lsgraham_uk
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So all that research and you bought a proton arena! What's next a felicia pickup. 
Technical Why Twinair never really worked
- Thread starter 306maxi
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Technical Why Twinair never really worked
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The 335d is the biggest spec diesel engine with two turbos on it!
A fairer comparison would be the 320d and surprise surprise https://www.honestjohn.co.uk/realmpg/bmw/3-series-f30-2012/320d it gets 85% of the promised KPM. Mine is doing 98% of the promised extra urban figure...
Diesels do fine when driven hard, on the occasion that I put my foot down and have a spirited drive, I struggle to get it to do less than 50mpg. The great thing about diesels like a 330d or 335d is that you will still end up with 40ish mpg even if you drive like a loon.
I would suggest that a van which will be stopping frequently, is probably not the best example to use.
Clearly a post to try and get a rise but hear goes will run with it. (although any post on here by anyone else who referred to anyone else as a numpty a dozen or more times gets threats of temporary bans
Seems the moderators only concern them selve with punishing those who share a different opinion to themselves? perhaps jrkitching shout wade in here?
The ideal stoimetric ratio of petrol is 14.1:1
The ideal Stoimetric ratio of diesel is about 14.7:1 which means more air to fuel, however diesel engines do not combust like petrol engine and don't need a perfect ratio of air, A diesel engine can run with a stoimetric ratio of 60:1 so 60 parts air to fuel meaning hardly any fuel is being burned, less fuel burned the less products of combustion are produced which means considerably less CO2. typically 30% less CO2 is produced by a diesel engine but with new euro6 standards that can be as far as 50% less versus an alternative petrol engine.
The problem here is the conversion between L/100km and miles per gallon, one is a measurement of distance covered using a volume of fuel the other is a measurement of fuel over a specific distance.
if you have a car that does 20mpg then you will only do 20miles on a single gallon of fuel (4.54litres). If you then do an extra 20 miles, then your car is doing 20miles per half gallon of fuel (2.27litres). If you do another extra 20 miles your car is now doing 6mpg and 20miles per third of a gallon of fuel (1.515 litres). the value of one gallon doesn't go down but the amount of miles you get per portion of fuel goes up. Whats important is the difference. the fiat uses 30% more fuel than the quoted figures.
With litres per 100km it works very differently as the distances stays the same but the amount of fuel goes down. so 20mg = 14.1litres of fuel, 40mpg equals 7.1litres. 60mpg = 4.71 litres. They haven't traveled any further, but less fuel has been used. The ratio remains the same. 4.71 litres is exactly a third of 14.1 litres.
no one with a an ounce of maths ability would believe that because your fiat 500 is getting 20mpg less than the quoted figure, would think that the fiat 500 is burning an extra 14 litres per 100 km. However.... If you had a 20mpg engine and it got 30% less than its stated 20mpg figures then it would be getting 14mpg. If it was getting 30% more than its stated figure then it would be getting 26mpg. but if you had a car which claimed 28.7mpg and this performed 30% below what was expected this would get 20mpg.
This is the joy of maths and using calculations you want to try and say what you want to say.
Simple facts the 500 twinair gets 30% less than claimed figures and will cost you about 50% more than you expected to pay in fuel bills.
On the flip side fiat dealers, especially here in the uk, can literally not less to be helpful.
Fiat might have said that when they where trying to flog another twinair to a customer. Much like a cosmetics sales woman tells my wife that what ever cream or potion she is trying to peddal is designed perfectly for her specific type of skin.
Most manufacturers are moving to 500cc cylinders in modular form which can be scaled up and down to meet the requirments. 1.5litre 3 cylinders, 2 litre 4 cylinders and 3litre 6 cylinders. and so on.
If 875cc was the perfect cylinder size then all supercars would be running 7 litre engines. instead there seems to be an abundance of 5.0 litre V10, 6litre V12s and 4-4.5 litre V8s.......
Renault 1.6 petrol= 0.666cc/ton. Worst peak hour city commute was under 30mpg - seriously impressive for 2.4 tons and a .45Cd. Lifetime average was 35mpg, 99% city/cbd use. Much better than anything that heavy should do - certainly better than the 2.3 petrol (24mpg!) and 2.4 diesel that I drove prior.
Interesting that My 1.6 multijet punto has essentially the same engine as my considerably lighter and less boosted 120 hp engine, and that only just averages 60mpg with a quoted figure of 62mpg, your van however has a quoted figue of 46.3mpg and you apparently manage 30% better than the experts can achieve in a laboratory setting with the absolutle best conditions.
As enthusiasts are all numpties and non-enthusiasts are also all numpties, this means, by your own standard you consider yourself and everyone else to be a numpty.
That said, there isn't a guy here saying he is leaving his car idling for 2 hours neither is anyone talking about nailing the throttle.
Given that Maxi is getting 70mpg from his 3 series and I get 60mpg from a 2litre diesel golf and 60mpg from an older 1.6 diesel punto. I would say we're pretty good at reading the road ahead and managing corners without event.
My VW has done 50k on its current and only set of brake pads, and is still going, so I can say hand on heart that the brakes are used very little.
Obviously though still a numpty as that's all you're seemingly able to repeatedly say, no reasoned or well thought out arguments, just insults and nonsense.
a fantastic contribution.
Seems the moderators only concern them selve with punishing those who share a different opinion to themselves? perhaps jrkitching shout wade in here?
Ok so 35g/km of CO2 over and above what is claimed. That not only would push the twinair up several tax brackets in countries all over Europe, it doesn't meet the figures that most larger modern diesel can manage.
So a car with more than three times the displacement of the twinair produces a staggering 57g/km extra in fuel. given that the BMW has a stated CO2 output of about 177g/km this equates to a difference of 32% above the claimed figures in a car that weighs as much as a house and isn't designed to be the most fuel-efficient car in the world (when you're paying upward of £40K you don't bother too much with the cost of fuel) versus a car claiming to be ultra fuel efficient and having a supposedly super frugal petrol sipping engine, producing 35% more Co2....
Plenty of diesels do very well around town they have low down torque perfect for stop start driving, new stop-start technologies use no fuel when stationary on both petrol and diesel engines. so like for like in town a diesel will also use a lot less fuel. on long runs and motorways, low geared cars like the twinair start to sruggle and economy figures creap up as the gearing is set more towards low speeds in urban areas. A big 2.0l german diesel will do 80mph all day every day at around 2000rpm.
Utter nonsence, its not a question of maths its a question of chemistry.
The ideal stoimetric ratio of petrol is 14.1:1
The ideal Stoimetric ratio of diesel is about 14.7:1 which means more air to fuel, however diesel engines do not combust like petrol engine and don't need a perfect ratio of air, A diesel engine can run with a stoimetric ratio of 60:1 so 60 parts air to fuel meaning hardly any fuel is being burned, less fuel burned the less products of combustion are produced which means considerably less CO2. typically 30% less CO2 is produced by a diesel engine but with new euro6 standards that can be as far as 50% less versus an alternative petrol engine.
The problem here is the conversion between L/100km and miles per gallon, one is a measurement of distance covered using a volume of fuel the other is a measurement of fuel over a specific distance.
if you have a car that does 20mpg then you will only do 20miles on a single gallon of fuel (4.54litres). If you then do an extra 20 miles, then your car is doing 20miles per half gallon of fuel (2.27litres). If you do another extra 20 miles your car is now doing 6mpg and 20miles per third of a gallon of fuel (1.515 litres). the value of one gallon doesn't go down but the amount of miles you get per portion of fuel goes up. Whats important is the difference. the fiat uses 30% more fuel than the quoted figures.
With litres per 100km it works very differently as the distances stays the same but the amount of fuel goes down. so 20mg = 14.1litres of fuel, 40mpg equals 7.1litres. 60mpg = 4.71 litres. They haven't traveled any further, but less fuel has been used. The ratio remains the same. 4.71 litres is exactly a third of 14.1 litres.
no one with a an ounce of maths ability would believe that because your fiat 500 is getting 20mpg less than the quoted figure, would think that the fiat 500 is burning an extra 14 litres per 100 km. However.... If you had a 20mpg engine and it got 30% less than its stated 20mpg figures then it would be getting 14mpg. If it was getting 30% more than its stated figure then it would be getting 26mpg. but if you had a car which claimed 28.7mpg and this performed 30% below what was expected this would get 20mpg.
This is the joy of maths and using calculations you want to try and say what you want to say.
Simple facts the 500 twinair gets 30% less than claimed figures and will cost you about 50% more than you expected to pay in fuel bills.
as the old saying goes, lots of more to go wrong, having said that We've had 4 BMW minis over the years and as yet have had nothing go wrong with them thats needed them to go back for any major repairs. There was a cosmetic issue with a texture used on the sterring wheel buttons but they replaced them without any quibble whatsoever. They will bend over backwards to do what ever they can for you and on one occasion one of the minis was in for service they lent me a 2 seires cabriolet to spend the day, with a full tank of fuel.
On the flip side fiat dealers, especially here in the uk, can literally not less to be helpful.
No idea what maths you are working too hear or what you are trying to say. Diesel and petrol cars add fuel with and without boost. when a diesel is floored then yes it will dmp a but of extra fuel in as will a petrol, however when on the normal 30mph run the diesel needs significantly less fuel, to keep it ticking over and running at a regular speed, versus a petrol car that still needs to match its fuel to the volume of air, reguardless of speed, run a petrol car too lean and damage the engine with excess heat, as indicated in the intial video these small petrol engines need extra fuel adding to prevent over heating and knock. Diesel engines run considerable cooler and do not suffer the same problems.
Depends on who you ask.
Fiat might have said that when they where trying to flog another twinair to a customer. Much like a cosmetics sales woman tells my wife that what ever cream or potion she is trying to peddal is designed perfectly for her specific type of skin.
Most manufacturers are moving to 500cc cylinders in modular form which can be scaled up and down to meet the requirments. 1.5litre 3 cylinders, 2 litre 4 cylinders and 3litre 6 cylinders. and so on.
If 875cc was the perfect cylinder size then all supercars would be running 7 litre engines. instead there seems to be an abundance of 5.0 litre V10, 6litre V12s and 4-4.5 litre V8s.......
Renault 1.6 petrol= 0.666cc/ton. Worst peak hour city commute was under 30mpg - seriously impressive for 2.4 tons and a .45Cd. Lifetime average was 35mpg, 99% city/cbd use. Much better than anything that heavy should do - certainly better than the 2.3 petrol (24mpg!) and 2.4 diesel that I drove prior.
do you have a 2.5 and a 2.4 engne as well to compare yourself?
Interesting that My 1.6 multijet punto has essentially the same engine as my considerably lighter and less boosted 120 hp engine, and that only just averages 60mpg with a quoted figure of 62mpg, your van however has a quoted figue of 46.3mpg and you apparently manage 30% better than the experts can achieve in a laboratory setting with the absolutle best conditions.
As enthusiasts are all numpties and non-enthusiasts are also all numpties, this means, by your own standard you consider yourself and everyone else to be a numpty.
That said, there isn't a guy here saying he is leaving his car idling for 2 hours neither is anyone talking about nailing the throttle.
Given that Maxi is getting 70mpg from his 3 series and I get 60mpg from a 2litre diesel golf and 60mpg from an older 1.6 diesel punto. I would say we're pretty good at reading the road ahead and managing corners without event.
My VW has done 50k on its current and only set of brake pads, and is still going, so I can say hand on heart that the brakes are used very little.
Obviously though still a numpty as that's all you're seemingly able to repeatedly say, no reasoned or well thought out arguments, just insults and nonsense.
a fantastic contribution.
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So all that research and you bought a proton arena! What's next a felicia pickup.
Handling by Lotus. Most fun FWD I've owned- lift off oversteer capable. No ESP to ruin your fun. Ridiculously practical - easily handles 4x8 sheet material - but small enough to park anywhere. 45mpg and mechanically unbreakable. Wish someone still sold such vehicles, nowadays all you can get is a stupid ladder frame truck, that drives like a stupid ladder frame truck.
Yes, because down sizing works - the EE video only highlights the challenges, not why it's impossible. Andy specifically said 'big'. Where we come from a 320 isn't big. Twin Turbos aren't exactly exotic these days.
I agree that you or I would still get 40mpg driven like a loon from a 335d, but the Numpties on HJ can only manage an 'average' 37. So how is that different from any other engine? I really tried to get as bad ecomony as the Numpties on HJ with my Twinair and really just couldn't. Why should the Numpties set the standard? I get 60mpg tank in tank out, and I have a passenger 95% of the time, which seems to make a difference.
My 1.6 Renault (the 'big' one with twin turbos) is even more downsized than your BMW and currently sitting on 101% of it's claimed city figure - which is what I look at since I average 26-30km/h - same as the NEDC city average speed. Keeping in mind I'm carrying around 400kg on board - and I've got the LWB fully optioned model - (the NEDC figures are for a SWB with no options- the effect of options is now being tested in WLTP).
I'm not a courier driver so no frequent stops. To work in the morning, home in the afternoon. Same as any other commuter. Besides, these downsized engines are supposed to be bad in stop and go /frequent stops.
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do you have a 2.5 and a 2.4 engne as well to compare yourself?
Interesting that My 1.6 multijet punto has essentially the same engine as my considerably lighter and less boosted 120 hp engine, and that only just averages 60mpg with a quoted figure of 62mpg, your van however has a quoted figue of 46.3mpg and you apparently manage 30% better than the experts can achieve in a laboratory setting with the absolutle best conditions.
As enthusiasts are all numpties and non-enthusiasts are also all numpties, this means, by your own standard you consider yourself and everyone else to be a numpty.
That said, there isn't a guy here saying he is leaving his car idling for 2 hours neither is anyone talking about nailing the throttle.
Given that Maxi is getting 70mpg from his 3 series and I get 60mpg from a 2litre diesel golf and 60mpg from an older 1.6 diesel punto. I would say we're pretty good at reading the road ahead and managing corners without event.
My VW has done 50k on its current and only set of brake pads, and is still going, so I can say hand on heart that the brakes are used very little.
Did a Fiat run over your cat? Specifically a Twinair?
Because frankly you'll find similar discrepancies with the makes you seem to love so much:
https://www.honestjohn.co.uk/realmpg/mini/cooperone-f56-2014/one-automatic 64%
I looked at a Mini before buying my 500, but I couldn't deal with the creaky plastic interior. Creaking armrests would drive me crazy, I tried the $55K+ coupe/cabrio thing as well and it had the same creaks. Dealer seemed really nice though
https://www.honestjohn.co.uk/realmpg/bmw/3-series-f30-2012/318i 57%
The NEDC test doesn't represent 'ideal' conditions - in fact it represents arbitrary conditions. If it did it would be impossible to beat:
https://www.honestjohn.co.uk/realmpg/volkswagen/t5-caravelle-2003/25-tdi
I used have one and averaged 125% of it's claimed MPG. The problem with your 'percentage' logic is that the new 1.6 uses less fuel, even though it's percentage of official figures is less stellar.
https://www.honestjohn.co.uk/realmpg/bentley/azure-convertible-1995
I mean we shouldn't all be driving Bentley's just because they exceed official figures, should we?
How do you know that the Numpties reporting on HJ aren't idling for hours on end? I mean I see it basically every day. I notice there's a slight trend for enthusiast vehicles doing better than Numpty mobiles, because they're less like to be driven by Numpties. The Toyota 86,ND MX5 and even Lotus doing particularly well.
You're basically saying that you and Maxi drive better than the Numpties on HJ, but you're only too quick too compare yourself to them. HJ says your Punto is only good for 50mpg, hardly better than the 44mpg of the Twinair that keeps triggering you (and that actually puts them equal terms of energy use and CO2). My 60mpg TA is 15% more efficient than your 60mpg diesel Punto.
That makes it only 10g CO2 over claimed.
You constantly go on about how great diesels are but when I say I get good economy from mine you suddenly doubt it? I average 6.7/100km tank to tank, but I regularly see as high as 8's and even 9's for single trips. For the average to work out I have to see trips in the 5's and even some times 4's. I get 70mpg cruising in 6th at 74km/h (minimum speed in top), sadly most of my driving is in 4th.
Diesels still use fuel mixtures to control heat (or NOx), except heat is less of an issue. The Stoichiometric ratio for petrol is 14.7:1.
A diesel engine has to burn 15% less than a petrol to match it's CO2 output, that is basic chemistry. So to match a 60mpg petrol a diesel has to be getting near 70mpg. To better a 60mpg petrol by 50% as you claim you'd have to have a small diesel car averaging 90mpg. That's the reality of diesel.
AGH1965
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Well, then it's time for real data. You may know that the 500 has the possibility to continuously log fuel consumption data to an USB stick to be analysed by FIAT's EcoDrive software. It is not too difficult to write your own software to analyse the data yourself. (You can find several examples on the internet.) So I did.
Below you see logged data from my previous 500 with TA85 Euro 5 engine and from my current 500 with TA80 Euro 6 engine. In both cases it is full throttle acceleration in 5th gear.
Both cars appear to accelerate equally fast, but the difference in fuel consumption is huge. It proves that FIAT managed to get rid of the extremely low air/fuel ratios at high engine loads by using a water-cooled exhaust manifold on the Euro 6 engine.
Both cars appear to accelerate equally fast, but the difference in fuel consumption is huge. It proves that FIAT managed to get rid of the extremely low air/fuel ratios at high engine loads by using a water-cooled exhaust manifold on the Euro 6 engine.
What’s interesting from your amazing 10 seconds of data....
Is that if you put your foot down in either car, despite the increase in speed, neither seem to see any increase in the amount of fuel consumed.... actually it looks like the fuel use goes down despite burying the throttle
So yeah, great way to prove your point with tip top accuracy
I looked at a Mini before buying my 500, but I couldn't deal with the creaky plastic interior. Creaking armrests would drive me crazy, I tried the $55K+ coupe/cabrio thing as well and it had the same creaks. Dealer seemed really nice though
The NEDC test doesn't represent 'ideal' conditions - in fact it represents arbitrary conditions. If it did it would be impossible to beat:
I used have one and averaged 125% of it's claimed MPG.
HJ says your Punto is only good for 50mpg, hardly better than the 44mpg of the Twinair that keeps triggering you (and that actually puts them equal terms of energy use and CO2). My 60mpg TA is 15% more efficient than your 60mpg diesel Punto.
That makes it only 10g CO2 over claimed.
You constantly go on about how great diesels are but when I say I get good economy from mine you suddenly doubt it? I average 6.7/100km tank to tank, but I regularly see as high as 8's and even 9's for single trips. For the average to work out I have to see trips in the 5's and even some times 4's. I get 70mpg cruising in 6th at 74km/h (minimum speed in top), sadly most of my driving is in 4th.
Diesels still use fuel mixtures to control heat (or NOx), except heat is less of an issue. The Stoichiometric ratio for petrol is 14.7:1.
A diesel engine has to burn 15% less than a petrol to match it's CO2 output, that is basic chemistry. So to match a 60mpg petrol a diesel has to be getting near 70mpg. To better a 60mpg petrol by 50% as you claim you'd have to have a small diesel car averaging 90mpg. That's the reality of diesel.
So several points to address, so here goes
1. you tried a mini but seem unsure if it was the coupe or the cabriolet, either way you found creaky arm rests too much to bear, but went out and bought a proton.... and the best bit is the R56 doesn’t even have arm rests as standard, infact very few have them and most that do have them fitted afterwards as an optional extra, don’t like it, flip it out the way or better yet mini will remove it.
2. The NEDC is a standardised test, manufacturers would do things to try and cheat the tests to get the absolute best numbers for example making sure the battery was completely, fully charged before the test began so there was no electrical load and therefore minimal drag from the alternator.
3. I’m glad you “used have one” no idea what you’re talking about but I’m happy for you!
4 & 5, you’re 1.6 Renault van has the same basic 1.6 litre engine as my punto, you’re however has 20hp more and considerably more weight and all the aerodynamic properties of the side of a barn.
One minute your are saying my smaller, lighter and much more slippery punto could only get 50mpg because that’s what a website with a known and rather dubious history of accuracy reports, on the other hand your bigger fatter ‘ fourgon de livraison de pâtisserie‘ can apparently, not only beat its own quoted figures by a huge margin, it can also beat the figures of much smaller, lighter cars that use the same engine but are less powerful.
And finally the last point is about diesels burning less fuel to meet the same figures of CO2 output as a petrol car, well the simple and undeniable fact is that Diesel engines are more efficient and getting energy from the fuel they burn, thermodynamically a petrol at its best is about 35% efficient at best, where as an average diesel can easily top 45% thermodynamic efficiency.
So off the bat a diesel is already getting 10% more energy from the fuel it burns, but then the way it burns the fuel equals more torque at lower speeds, it means again less fuel burned to achieve peak power, a petrol will typically achieve peak power at 6000rpm while a diesel will do it at 4000rpm. So again less fuel needed. Then a petrol car does indeed need a very specific stoimetric ratio of air to fuel, too little and you get too much heat, knock and damage the engine, too much and you don’t burn all the fuel and emit huge amount s of unburnt hydrocarbons and CO which the catalyst turns to CO2.... man while diesels don’t need a perfect ration because they burn the fuel rather than exploding it, the burn is slower and longer, the engine ignites due to reaching flash point rather than relying on a spark.
The amount of air is irrelevant, it’s the amount of fuel you put in to a diesel, and so the throttle is controlled by pumping more or less fuel in to keep a diesel ticking over you need next to no fuel, and they can keep chugging over at very low revs on tiny amounts of fuel, with the same amount of air for each charge. A diesel will still run with a fuel air mix of 60:1 a petrol can never do that. This is the reason all diesel versus petrol cars, like for like use much less fuel and emit less CO2.
A prime comparison is the 1.2 fiat 500 with 70hp and 1250cc capacity, versus the 1.3 multijet diesel with 1250cc capacity and 95hp
Despite a turbo, a more powerful engine and the added weight of the Diesel engine, the diesel CO2 output is ~100g/km, while the 70hp non turbo petrol car produces ~112g/km
You could argue the turbo on the diesel makes it more efficient but by your standard model of stoimetric figures the turbo means more air which means a directly proportionate amount of fuel is needed to match the increase in air, it’s just not the case at all.
If you just burn a litre of petrol in the open and a litre of diesel in the open then yes diesel will produce more carbon and that is chemistry, however in an engine a diesel doesn’t need to burn as much fuel as a petrol engine, to get the same amount of power and performance per litre.
seriously go look it up!
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Such a Mini fan and doesn't even know Mini made a Coupe/ Cabrio thing:
https://en.wikipedia.org/wiki/Mini_Coup%C3%A9_and_Roadster
Really the armrests in the doors were optional? Were the door trims an option too?
You're obviously not a car guy if you don't understand the value of owning a 'beater'. The surprise is how many looks and comments the Proton gets. When Mini make a vehicle that can handle half a ton of gravel, let me know. On second thoughts, forget it, I won't be dumping gravel into a $50k vehicle anyway.
When HJ confirms Andy's point:
When HJ undermines Andy's point:
Either we use HJ's number across the board, or we go with out own experience, that is my point. Andy's the one only too quick to claim that a Twinair can only get 44MPG, while HIS Punto gets 60MPG - conveniently ignoring that HJ's average is only 50MPG.
44MPG petrol matches 50MPG from a thermodynamic efficiency point of view (assuming the same car- I think the Punto has the aerodynamic advantage). 60MPG from my TA beats 60MPG from a diesel.
Andy can't even fathom that there's a massive difference between a single trip, and a tank average. If you get 60MPG, you're going to have individual trips well in excess of that. Anyone who bothers to watch their MPG daily will know that. The ~40MPG tank to tank for my van is nothing unreasonable - only a couple of MPG better than the HJ figure, and only 102% ahead of official. There's a statistically 1 in 400 chance that every light on my commute will be green - in theory that happens once a year. So on that day my economy will be much better than on that statistical day where the opposite happens. Making zero stops in city driving is much better than the NEDC test. I specifically said 'best commute' and gave my tank averages as well, but certain types will miss the point and then fixate over it.
Since I have seven cars to maintain - they each get hooked up to solar power when parked - for me precharging does represent the real world, and frankly for modern cars regular grid charging the battery is a very good idea.
Do you know the story of how GM fitted lock out devices to their V8 engines, forcing you to shift from 1st to 4th in the name of test cycle efficiency? That shows how arbitrary the test cycle is - too slow for peak efficiency of some engines. I shift my NA cars 1-3-5, not allowed under NEDC, but good for economy.
No, you need to look it up. 1 litre of open petrol/ diesel burning in open air produces exactly the same Co2 as burning it in an engine. Unless you have an engine with some kind of Co2 trap, which we all know doesn't exist. The only reason you get more power out of a litre of diesel is because one litre of diesel contains 15% more power (energy) and therefore there's 15% more Co2. Therefore if you get a real world 60MPG petrol car you're using 15% less energy/Co2 than a 60MPG diesel.
For the sake of simple numbers:
~50MPG petrol = ~60MPG diesel.
~60MPG petrol = ~70MPG diesel.
So a 60MPG diesel isn't really that impressive, since plenty of petrols can get 50MPG.
In the real world we know the Fiat 1.2 does 60MPG, and we also know the Diesel does 70MPG, so they are thermodynamically all but equal. It's interesting that current petrol engines we know are 35-40% efficient, but you'll never find thermodynamic efficiency published for any diesels. Best I've found is scholarly articles some claiming as low as 35% for diesels. Diesel 'efficiency' is largely just a quirk of measuring fuel in litres rather than kilos.
Plus, call me crazy, but I prefer not having my car fill with diesel fumes every time it stops, which makes me even happier with my 69MPG diesel equivalent TA.
https://en.wikipedia.org/wiki/Mini_Coup%C3%A9_and_Roadster
Really the armrests in the doors were optional? Were the door trims an option too?
You're obviously not a car guy if you don't understand the value of owning a 'beater'. The surprise is how many looks and comments the Proton gets. When Mini make a vehicle that can handle half a ton of gravel, let me know. On second thoughts, forget it, I won't be dumping gravel into a $50k vehicle anyway.
When HJ confirms Andy's point:
When HJ undermines Andy's point:
AndyRKett said:
Either we use HJ's number across the board, or we go with out own experience, that is my point. Andy's the one only too quick to claim that a Twinair can only get 44MPG, while HIS Punto gets 60MPG - conveniently ignoring that HJ's average is only 50MPG.
44MPG petrol matches 50MPG from a thermodynamic efficiency point of view (assuming the same car- I think the Punto has the aerodynamic advantage). 60MPG from my TA beats 60MPG from a diesel.
Andy can't even fathom that there's a massive difference between a single trip, and a tank average. If you get 60MPG, you're going to have individual trips well in excess of that. Anyone who bothers to watch their MPG daily will know that. The ~40MPG tank to tank for my van is nothing unreasonable - only a couple of MPG better than the HJ figure, and only 102% ahead of official. There's a statistically 1 in 400 chance that every light on my commute will be green - in theory that happens once a year. So on that day my economy will be much better than on that statistical day where the opposite happens. Making zero stops in city driving is much better than the NEDC test. I specifically said 'best commute' and gave my tank averages as well, but certain types will miss the point and then fixate over it.
Since I have seven cars to maintain - they each get hooked up to solar power when parked - for me precharging does represent the real world, and frankly for modern cars regular grid charging the battery is a very good idea.
Do you know the story of how GM fitted lock out devices to their V8 engines, forcing you to shift from 1st to 4th in the name of test cycle efficiency? That shows how arbitrary the test cycle is - too slow for peak efficiency of some engines. I shift my NA cars 1-3-5, not allowed under NEDC, but good for economy.
No, you need to look it up. 1 litre of open petrol/ diesel burning in open air produces exactly the same Co2 as burning it in an engine. Unless you have an engine with some kind of Co2 trap, which we all know doesn't exist. The only reason you get more power out of a litre of diesel is because one litre of diesel contains 15% more power (energy) and therefore there's 15% more Co2. Therefore if you get a real world 60MPG petrol car you're using 15% less energy/Co2 than a 60MPG diesel.
For the sake of simple numbers:
~50MPG petrol = ~60MPG diesel.
~60MPG petrol = ~70MPG diesel.
So a 60MPG diesel isn't really that impressive, since plenty of petrols can get 50MPG.
In the real world we know the Fiat 1.2 does 60MPG, and we also know the Diesel does 70MPG, so they are thermodynamically all but equal. It's interesting that current petrol engines we know are 35-40% efficient, but you'll never find thermodynamic efficiency published for any diesels. Best I've found is scholarly articles some claiming as low as 35% for diesels. Diesel 'efficiency' is largely just a quirk of measuring fuel in litres rather than kilos.
Plus, call me crazy, but I prefer not having my car fill with diesel fumes every time it stops, which makes me even happier with my 69MPG diesel equivalent TA.
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What’s interesting from your amazing 10 seconds of data....
Is that if you put your foot down in either car, despite the increase in speed, neither seem to see any increase in the amount of fuel consumed.... actually it looks like the fuel use goes down despite burying the throttle
So yeah, great way to prove your point with tip top accuracy
Again you show a complete lack of understanding. I don't even know where to begin to explain.
I'll let you have a think about it.
AGH1965
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The accuracy is surprisingly good. If the logged fuel flow in litres per hour is integrated over a long period with multiple refuelings, then it is within a few percent of the real litres.
That you don't believe reality, that is your problem. Don't make it ours.
Deuce........New balls please...
AGH1965
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The reason for showing these 10 seconds is that here the accelerations match surprisingly well. Otherwise you would have complained about that.What’s interesting from your amazing 10 seconds of data....
Is that if you put your foot down in either car, despite the increase in speed, neither seem to see any increase in the amount of fuel consumed....
The figure below shows the same accelerations, but now for a longer time and in this case the logged fuel flow in litres per hour is shown.
As you see, the fuel flow definitely increases when the speed increases. There is nothing wrong with this data! When accelerating to 160 km/h (100 mph) the Euro 5 TA even exceeds 30 litres per hour!
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there was a coupe, and there was a roadster and there was a cabrio, 3 different cars, I was trying to confirm which one you claim to have driven, your lack of understanding here, to me suggests none of them. also
Really the armrests in the doors were optional? Were the door trims an option too?
As i said, we've owned 4 minis, not just once est driven one on one occasion and we've driven a dozen more different minis when the car has been in for servicing, of all the complaints I do have about the mini, creaking arm rests has never affected any of them..
As yu come from a country full of V8 utes, I can't imagine that a proton makes anyone turn their hear or feel envious in anyway.
In comparing data on Honest John website. There are at best 120 (data available from howmanyleft.co.uk) Punto 1.6mjtd in the UK they only made them from 2010 -2013 and next to no one bought them, conversely there are thousands and thousands of fiat 500's with a twinair engine.
So weighing up the accuracy of data on such sites its best to bare in mind how many driver/owners will be uploading data. For the punto numbers could be as low as one bloke once uploaded one tanks worth of fuel of driving, with economies of scale its likely considerably more people are uploading twin air data or renalt van data and over longer periods of time, meaning that information is likely to be more accurate. You can keep going back to that site as much as you want, there are other sites about, some discussed in this thread which shows different figures to HJ.
My claim of the twin air doing 44mpg was taken from a website where you could seel all the data for over 100 cars across thousands of miles of driving. you just get a figure on HJ, and no idea of the data set behind it.
why are you now comparing a punto to the twinair, I was comparing your claim that you similarly engined van to my punto can some how magically 60mpg on a run with much more power, and weight and the aerodynamics of a shed, yet you claim that a much smaller lighter, more aerodynamic and less powerful car is incapable of achieving this on a regular basis. I'm not getting over the claimed MPG figures for the car, yet you scoff at what I say then claim your van with 400KG in the back can get highter than the claimed figures
This is where you make no sense at all.
The relative energy density per litre of fuel is about 35Mj/L for diesel and 34MJ/L for petrol, so you plucked your 15% figure out of thin air.
you can look all this stuff up online, but there is more carbon per litre in diesel than in petrol so to combust 1 litre of petrol and one litre of carbon you will produce slightly more CO2, however you're ignoring all other byproducts of combustion, diesels are lean burn and tend to combust more of the fuel extracting more of the energy for every litre given than a petrol does. A petrol car is more reliant on a perfect mix of air and fuel, for a perfect combustion while managing hear, which if even fractionally under or over fueled will lead to heat build up and potential knock, or incomplete combusion, were an element of fuel is wasted and the car produces more Carbon monoxide and unburnt hydrocarbons, the CO gets turned by the catalyst into more CO2 and the hydrocarbons get pumped into the air as microscopic droplets of petrol. As shown in the video right at the begining of this thread, small turbos need to deliberately overfuel to manage engine temperatures and exhaust tempretures to prevent engine damage.
Stop-Start, been fitted to most cars for the last 7 - 8 years, not really a problem.
The reason for showing these 10 seconds is that here the accelerations match surprisingly well. Otherwise you would have complained about that.
The figure below shows the same accelerations, but now for a longer time and in this case the logged fuel flow in litres per hour is shown.
As you see, the fuel flow definitely increases when the speed increases. There is nothing wrong with this data! When accelerating to 160 km/h (100 mph) the Euro 5 TA even exceeds 30 litres per hour!
Whats really weird about this new graph you've posted, supposedly from the same data as before, is that your new data shows an increase in fuel consumption from 17ishL/h to 20L/h with acceleration from 5 - 15 seconds, when your previous graph showed an almost completely flat 15L/h for the same car over the same period.... yet you claim its accurate?
and besides all of that, these are different cars driven at different times, we don't know on what roads, in what conditions, on hills or inclines, at what altitude or with how much weight in the car. wind direction, the list goes on.
You have taken a 10-second snippet of information from only two cars and searched the data for instances where the road speed and acceleration matched then looked at the fuel being used.
Even Andrew Wakefield used more data than that and look how his research turned out
I have a friend who is a specialist 'Data miner' He writes computer programs which will analyse whatever data you give him and show whatever you want it to show.
You're both arguing in circles here and quite frankly its not adding anything to or in anyway detracting from Maxi's orignal post way back at the start.
It doesn' matter what fuel economy figures any other car does or doesn't get, or the CO2 output, or the pros and cons of petrol V diesel, nore does it matterhow much an armrest rattles on a mini (hard to believe I know!) for the purposes of this thread, the Twinair engine does not and can't in regular normal use get anywhere near the figures fial claimed for it back in 2010. which is why I suspect the Twinair is being ditched for a newly designed engine after just 8 years in production, meanwhile the 1.2 is still going strong 25 years on.
AGH1965
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The first graph was l/100km, the second is l/h. Don't you get the difference?
Very lame! I did my best to provide a honest comparison. At least I contributed to this discussion by providing data. That can't be said about you.
Hm the thread seems to be getting a bit off topic here.
couple of things to say. wasn't the twinair more of a replacement to the 1.4 16v? hence the 85 and 105 hp comapred to the 1.4's 100-ish hp? Only it was meant to be better on fuel, lower on emissions but similar performance.
If I remember correctly the idea of downsizing engines is with smaller capacity and a turbo charger is to have for example a 1.4 turbo with similar performace to a 1.8 N/A engine but when driven slowly or sensibly keep similar economy to a 1.4. Weather it works or not people argue for both sides.
I own an Abarth (2016 euro 6 140hp) I average between 39 and 43 mpg mixed drivng and occasionally putting my foot down. I'd consider that pretty food for what the car is and the T-jet isn't exactly a super modern engine
couple of things to say. wasn't the twinair more of a replacement to the 1.4 16v? hence the 85 and 105 hp comapred to the 1.4's 100-ish hp? Only it was meant to be better on fuel, lower on emissions but similar performance.
If I remember correctly the idea of downsizing engines is with smaller capacity and a turbo charger is to have for example a 1.4 turbo with similar performace to a 1.8 N/A engine but when driven slowly or sensibly keep similar economy to a 1.4. Weather it works or not people argue for both sides.
I own an Abarth (2016 euro 6 140hp) I average between 39 and 43 mpg mixed drivng and occasionally putting my foot down. I'd consider that pretty food for what the car is and the T-jet isn't exactly a super modern engine
AGH1965
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You are right. In my country the 1.4 16v disappeared ingloriously when the TA was introduced.
But now we have new problem, since the almighty Honest John doesn't know the 500 with 1.4 16v. Oh dear, how will Andy and Maxi survive this?
I see the 500 TA as a very lukewarm hot hatch with a comfy ride. And from mid '17 top rate spec as a Lounge in Red Coral. Sure you may spend all the price difference between that and a proper hot hatch on fuel, but I'd argue who cares? Modern cars pretty boring, small Fiats are fun, hence Maxi has gone to time and trouble to get his back on the road. 1.2 is fun in it's own way.
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jrkitching can you just lock this damn thread?
Aye! you are never sure what threads will go on & on & on & on, well, just practically go all over the place . Apart from this being quite a large forum & there is "some" on here that just cannot resist commenting more than is really necessary, but hey ho that's human nature fore you. It can get a bit entertaining though for all the wrong reasons as has been seen so many times before......Just my observations.
It's only too easy to vent your feelings in front of a computer screen to total strangers, simple. As I've said before willy waving can take on many faces, & to a certain degree I've done it myself when I first started on here. Strung out on tramadol & sav blanc getting over a hip replacement operation, & getting to grips with the workings of a computer for the first time. I have to admit I used the forum as a form of amusement at times. Further on up the line, I'm older,wiser & off the drugs...
It's only too easy to vent your feelings in front of a computer screen to total strangers, simple. As I've said before willy waving can take on many faces, & to a certain degree I've done it myself when I first started on here. Strung out on tramadol & sav blanc getting over a hip replacement operation, & getting to grips with the workings of a computer for the first time. I have to admit I used the forum as a form of amusement at times. Further on up the line, I'm older,wiser & off the drugs...
