Technical Why Twinair never really worked

[AGH1965]

It’s almost like the video in the first post of this thread was made by an engineer that knows what he’s talking about!

No one said the guy told crap, but you used it to bash the TA. With a TA especially the brainless drivers are heavily punished when it comes to fuel economy. More sensible drivers don't have to drive slow at all to realise very acceptable mpg figures. Guess which group of drivers complains the most...

 

[306maxi]

No one said the guy told crap, but you used it to bash the TA. With a TA especially the brainless drivers are heavily punished when it comes to fuel economy. More sensible drivers don't have to drive slow at all to realise very acceptable mpg figures. Guess which group of drivers complains the most...

Stop being emotional, it’s an engine and we’re having a factual discussion about it.

 

[PuntoHowTo]

With a TA especially the brainless drivers are heavily punished when it comes to fuel economy. More sensible drivers don't have to drive slow at all to realise very acceptable mpg figures.

Yeeeeah..... If I buy a car I want it to get me from A to B occasionally via Starbucks, and I want it to achieve reasonable MPG figures as quoted in the literature.

What I absolutely don't want is a car that will get within 20% of the quoted figures if you turn off anything and everything electrical, fold in the door mirrors, tape up the shut lines and then never exceed 2000rpm even up the steepest of hills.

A car should be brainless, get in and drive without having to carefully consider every exact bump and undulation in the road and how it might impact my fuel economy.

My 1600KG golf cabriolet will beat a TA hands down on fuel economy all day every day from its 2-litre diesel engine, and won't scream if you want to do 80 down a european motorway with a boot full of luggage and the roof down. 60mpg without driving mike Mr Magoo on sedatives. It is reasonable that a car should be capable of doing this. Quoted figures on my VW are something like 62-64mpg and I get 60mpg without breaking a sweat. So by saying that the brainless are the ones being punnished, 99% of fiats customers, will not be eco drivers trying to eak out every last drop of fuel and will just want to get from A - B like me.

 

[Twinkletwinklelittlestar]

Yeeeeah..... If I buy a car I want it to get me from A to B occasionally via Starbucks, and I want it to achieve reasonable MPG figures as quoted in the literature.

What I absolutely don't want is a car that will get within 20% of the quoted figures if you turn off anything and everything electrical, fold in the door mirrors, tape up the shut lines and then never exceed 2000rpm even up the steepest of hills.

A car should be brainless, get in and drive without having to carefully consider every exact bump and undulation in the road and how it might impact my fuel economy.

My 1600KG golf cabriolet will beat a TA hands down on fuel economy all day every day from its 2-litre diesel engine, and won't scream if you want to do 80 down a european motorway with a boot full of luggage and the roof down. 60mpg without driving mike Mr Magoo on sedatives. It is reasonable that a car should be capable of doing this. Quoted figures on my VW are something like 62-64mpg and I get 60mpg without breaking a sweat. So by saying that the brainless are the ones being punnished, 99% of fiats customers, will not be eco drivers trying to eak out every last drop of fuel and will just want to get from A - B like me.

...so you’re nominating yourself for which category?

 

[Mercky]

Think I’ll sell mine, it drinks juice and it’s not even any fun to drive, what was I thinking? I feel an i10 coming on.......

 

[PuntoHowTo]

...so you’re nominating yourself for which category?

Brainless when it comes to getting from A - B. I have far more important things to think about, than if I would be better off keeping it in 2nd for a few more rev or if I should change up earlier, or maybe I need to hang behind every lorry doing 56mph just to squeeze an extra 2mpg/per year.

If you treat any car as people are saying you need to treat a TA in order to get good fuel economy, then guess what? every car will give you better fuel economy!! I know its a surprise, but when coming out with idiotic comments like this, then you have to consider who is really brainless

 

[PaulD]

This is a very interesting discussion. Thank you everyone for your contributions. My experience with the TA in my Panda Cross has been very good. I don’t use the eco setting, leave the climate control on auto and set at 20 degrees C. I’ve never averaged less than 50mpg and often close to the manufacturers figures - see photo. After another 2500 miles touring Ireland, two up and a bike rack the economy has dropped to 55.9 mpg.

 

[gar074]

After another 2500 miles touring Ireland, two up and a bike rack the economy has dropped to 55.9 mpg.

PaulD's posts always leave me bemused, depressed, amazed and impressed, in equal measure.

 

[puntofan01]

10kg is a big deal when designing a car.

10kg for a battery here 5kg for something else there, saving every gram where you can, can mean the difference between the car meeting emissions requirements, which can make big differences in sales tax, can mean the difference between a car selling or not.

Fiat stopped putting spare wheels in cars a long time ago for the very reason of saving weight, as have many manufacturers. So Maxi is 100% right, 10kg might not seem a lot and yes one driver can weigh considerably more than another, but the carrying capacity of the car can be higher if they save every ounce where ever they can.

Weight costs money as well, every extra nut bolt and screw that’s not needed is wasted money, and for a high volume car like the 500 every extra unnecessary bolt could add Millions to the production costs across the life span of the production run.

So on this point Maxi is spot on.

I've got to ask: if that's the case, then how on earth are some cars so insanely heavy? For example, surely land rover could've designed the previous discovery so it weighed rather less than 2.7 tonnes?

 

[AGH1965]

So by saying that the brainless are the ones being punnished, 99% of fiats customers, will not be eco drivers trying to eak out every last drop of fuel and will just want to get from A - B like me.

You completely misinterpreted my post. I didn't mean hypermiling or eco driving at all. With the brainless I meant those who have no idea how easy it is to save a lot of fuel. For example, they find the gearshift indicator annoying, since they think they know much better what gear to use, although they don't. They don't look ahead and therefore never coast in gear towards a red trafic light. They never use S&S even when the car is more stationary than moving in city trafic. For some odd reason exactly those people complain the most about lousy mpg figures.

My current TA does 53 mpg (average over almost 40k miles). Just normal driving, no hypermiling or eco driving at all. It could have been a lot better if I would drive more on rural roads, but unfortunately I drive almost only on 75-80 mph motorways and in the city. These mpg figures don't come near the official ones, but that doesn't make me angry at all. In fact, I'm quite satisfied. There are several reasons one can be dissatisfied about the TA, but for me fuel economy isn't one of those.

 

[lsgraham_uk]

75% through a 500 mile trip in my abarth xsr, I am looking at averaging 40mpg. What is most obvious is that if I could bumble along at 40-50 I would easily match official figures.

I am away with some friends in a 996 carrera (tiptronic) and the twitchy foot keeps pressing a little harder than average. Said owner has been amazed by the noise, and the fact that if I accelerate from 30 in second gear to top end of third he cannot gain on me. Sadly aerodynamics is a cruel mistress.

 

[PuntoHowTo]

Sadly aerodynamics is a cruel mistress.

That and gearing...

 

[Goudrons]

I've got to ask: if that's the case, then how on earth are some cars so insanely heavy? For example, surely land rover could've designed the previous discovery so it weighed rather less than 2.7 tonnes?

It probably could have, but at the time they used old production techniques that required a separate chassis.

The very nature of their products lead them to perhaps lower their expectations of weight and fuel economy on this model.

If I think back and hazard a guess you're referring to the L319, which was the heaviest model at around 2400kg, I believe if you loaded the boot and towed the max permissible by the factory, you'd need a HGV license.

It could handle a 3500kg trailer with a nose weight of something like 150kg across a ploughed field, you can't do this with spit and kleenex, you need large chunks of steel.

I remember the first trip to a petrol station in my first Disco (and the second the next day), it still makes me shudder!

In regards to the latest trend of downsizing, I think we are only just at the start of the process.
The technology to truly make these engines and cars really efficient isn't yet cheap or light enough, there's also no consensus between manufacturers on which system is best or which system may have a future, the rules haven't been stable, clear or global.
It's probably safe to say the governments haven't really helped, the income generated by taxation on fuel will need to come from somewhere if it suddenly reduced or dried up, which is why there hasn't been the large investment in public charging stations for EVs.

I hope the fact that the new tests will be worldwide with worldwide goals that will focus their attention and it won't be long before we see more small petrol engines running Miller or Atkinson cycles, helped along with cheap, light and reliable hybrid systems.

 

[AGH1965]

MPG figures are supposed to be representative, that’s not to say you’ll get exactly that figure no matter where you live but you could expect results in the region of.

If there is a small difference 10% or so then that’s one thing but when there is a 30+% difference then it’s a clear case of misrepresentation.

It is an illusion to have official mpg figures that differ only 10% from everyone's real mpg figures. The difference between motorways, rural roads and city is already larger and the driving style/skills also have a large influence.

To illustrate that, I will show you some results from the German Spritmonitor website. (It is a kind of a German version of feully.com.) I created the following selection trying to make an honest comparison with my previous TA:
- FIAT 500
- 2011
- 85 hp TA (62-64 kW, petrol)
- manual gearbox
- results of at least 2000 km (1243 miles) submitted

This selection currently gives the following results:
- Number of cars: 53
- Best: 4.96 l/100km (57 mpg)
- Average: 6.03 l/100km (47 mpg)
- Worst: 8.55 l/100km (33 mpg)
- My previous TA: 5.45 l/100km (52 mpg)

What official mpg figure should FIAT have published to have a difference of no more than 10% for all of these cars???

 

[PuntoHowTo]

What official mpg figure should FIAT have published to have a difference of no more than 10% for all of these cars???

44mpg

Your selection of cars forms a bell curve, obviously there will be those who are pushing to get the best fuel economy they possibly can, and there will be those who thrash their cars about all over the place with no thought to the economy.

However most of those figures listed fall within about 10% of 44mpg

They even put that bell curve right there on the page.

 

[AGH1965]

44mpg

44 mpg? That is 6.4 l/100km. That is insane!

Especially when I compare it with the results of my previous TA:

Even the 4768 km (2963 miles) that I drove the car like a madman, doing almost every acceleration full throttle but with obeying the legal speed limits, my average was better than 6.4 l/100km.

 

[PuntoHowTo]

Ok so this was your question

What official mpg figure should FIAT have published to have a difference of no more than 10% for all of these cars???

I answered the above question using the data you provided. 44mpg

44 mpg? That is 6.4 l/100km. That is insane!

Nooooooo! What’s really insane is asking someone to answer a question based on the data you provided then disagreeing with that answer, despite having posted the data yourself that proves the rule.

The average is even there on the page for you to see! 6.03l/100km or 46.86mpg
Interestingly if you change the year of manufacturer from just 2011 cars, to 2011 - 2018, you still get the same figure 6.03l/100km but now you have the data from 131 different cars!

The range (2011 only) is 4.96 - 8.55 so a spread of 3.59, so the mid point of that range is 6.75l/100km so 41.8mpg

The Median of that data (2011 only) = 6.30l/100km or 44.85mpg so still worse than your claimed “madman” driving.

I don’t know what you want me to say? You provided the data and it shows that the TA is not as fuel economic as you’re claiming, don’t shoot me when you don’t agree with your own data!

 

[lsgraham_uk]

Ok so this was your question



I answered the above question using the data you provided. 44mpg





Nooooooo! What’s really insane is asking someone to answer a question based on the data you provided then disagreeing with that answer, despite having posted the data yourself that proves the rule.

The average is even there on the page for you to see! 6.03l/100km or 46.86mpg
Interestingly if you change the year of manufacturer from just 2011 cars, to 2011 - 2018, you still get the same figure 6.03l/100km but now you have the data from 131 different cars!

The range (2011 only) is 4.96 - 8.55 so a spread of 3.59, so the mid point of that range is 6.75l/100km so 41.8mpg

The Median of that data (2011 only) = 6.30l/100km or 44.85mpg so still worse than your claimed “madman” driving.

I don’t know what you want me to say? You provided the data and it shows that the TA is not as fuel economic as you’re claiming, don’t shoot me when you don’t agree with your own data!

I would have loved that average in my twin air lounge, 40 was all I could manage, but my journeys are usually super short.

 

[StevenRB45]

My one and only experience of a twin air managed 33mpg..only time I've felt the need to top up a courtesy car twice in the same day.

I feel as though that actually represents what you can achieve with "madman" driving although the faster and more powerful Suzuki I had at the time managed 37mpg in the same use..

 

[PuntoHowTo]

My one and only experience of a twin air managed 33mpg..only time I've felt the need to top up a courtesy car twice in the same day.

I had a 2litre 130bhp 1996 Saab 900 that would average more then 33mpg in regular use, which is a shocking comparison to a much smaller much lighter much newer Twinair engine of a 500.

I bought the car off eBay for £400, I then drove it from Norwich in Norfolk, to Ghent in Belgium via the channel tunnel and back again on one tank of fuel (68 litres) in one day and averaged 45mpg, even with the 80mph speeds on the continent, and a boot full of duty free on my way home oh and 3 people on board. :slayer:

Ironically the reason I got rid of it was the fuel cost, at the time I was doing 500miles a week and could not afford the £70 weekly fuel bill

That’s when I bought my punto multijet, which would do it’s quoted 62.5mpg and at the time Diesel was cheaper than petrol so I made a double saving.