Technical Can Stilo 2.4 use 91 Octane unleaded?

[bhe130]

Can Stilo 2.4 use 91 Octane unleaded? Is there going to be any problems?

Cheers

 

[Shadeyman]

Australia's "regular" unleaded fuel is 91.

If there's and Australian 2.4 owners on here let us know..

 

[Yellow Peril]

I'm sure it would run, though power will be down I guess. Whether long-term use could cause valve damage, I don't know. I thought the emissions kit (lamda sensors etc) would rein back the timing to prevent pre-detonation and other potentially damaging effects...

 

[sixpotman]

Normally it would be the Knock sensor and ecu that retarded
the ignition until there was no pinking.

John

 

[Morty Mort]

I think (read ages ago) that using too low octane will cause abnormal combustion resulting in a higher pressure on the engine's internal components - just as a too advanced ignition timing. Use 98 instead.

 

[Morty Mort]

Normally it would be the Knock sensor and ecu that retarded
the ignition until there was no pinking.

John

Ofcourse. I keep forgetting the automatic adjusting. On earlier cars we just turned the distributor a couple of degrees.

 

[richydraper]

yes...

the octane (RON) rating is a measure of resistant a fuel is to knock... the higher the figure the more likely it is to knock. (i.e. how volatile the fuel is)

lower RONs wont be as responsive or give as much power but i cant imagine it would be that noticable.

i personally have never felt any difference between 95 and 98 RON fuels in any of the cars or bikes ive had. i wouldnt see a problem with using 91 RON at all

the yanks use 85 RON as their 'normal' unleaded and they run pretty much every car apart from fiats/alfas, due to saftey regs (altho they have started allowing the new 500 over there) i cant see our little lancias having any problem running on any fuel that you can buy from any pump anywhere around the world...

heres an idea... put some in and try it! its not gonna kill your engine!!

 

[vladof]

The manual says to use petrol no lower than 95. It does say to put unleaded in all circumstances and never leaded but it does not say your engine will explode if you put a lower octane unleaded inside.



It should work.

I use 98 and even 101 petrol all the time and believe me there's a big difference in how the engine reacts. Sharper acceleration, sharper engine response and noticeably more power.

 

[Morty Mort]

I use 98 and even 101 petrol all the time and believe me there's a big difference in how the engine reacts. Sharper acceleration, sharper engine response and noticeably more power.

I use 98 aswell, and the car uses less fuel pr. km. If I run 95 on a 350 km trip, I average at 6.8-7.0l / 10 km (full car). The same trip on 98 octane average at 6.2-6.4l / 10 km (full car). Strange but true, I've tested it several times over 5 years on the same trip, from one town to the other.

I just changed my plugs, after 2 years on 98 octane. They looked perfect, with an off-white "powdercoat" look with microscopic erosion.

 

[neonglow]

LPG has a RON (Research Octane Rating) of 110, but I don't feel any performance or milage gains I think it's the calorific value that matters, as Morty already said RON simply descripbes the tendency of Gasoline, Petrol etc to self ignite during compression. 98, 95 and 100 RON gasoline has almost the same calorific value, so it's doubtful you would have better milage or power...

 

[vladof]

I use 98 aswell, and the car uses less fuel pr. km. If I run 95 on a 350 km trip, I average at 6.8-7.0l / 10 km (full car). The same trip on 98 octane average at 6.2-6.4l / 10 km (full car).

Yeah yeah, I forgot to mention the economy. Mine doesn't go down by a liter but more of a .5 liter/100 km. Instead of 7.4 I may be able to reach 6.7-6.8. I can only get 6.2 or even 5.8 if I never go over 100 km/h and rarely stop for anything, but nevertheless, mine is a 1.8 so I should expect a difference.

LPG has a RON (Research Octane Rating) of 110, but I don't feel any performance or milage gains I think it's the calorific value that matters, as Morty already said RON simply descripbes the tendency of Gasoline, Petrol etc to self ignite during compression. 98, 95 and 100 RON gasoline has almost the same calorific value, so it's doubtful you would have better milage or power...

Everyone knows that LPG is a lot worse than gasoline. You are right it's not just the RON that matters but it's a much more complicated ecuation in mixtures that would give the petrol more power. We have a lot of taxis in Bucharest that run on LPG, their cars are pathetically slow. (1.4 or 1.6 Dacia Logan). You should check out "Heat of Combustion" on Wiki to see what really gives the engine power.

In regards to Octane Ratings Wiki says: "Octane rating does not relate to the energy content of the fuel (see heating value). It is only a measure of the fuel's tendency to burn in a controlled manner, rather than exploding in an uncontrolled manner. Where the octane number is raised by blending in ethanol, energy content per volume is reduced."

If I look at the charts I still see LPG as containing a higher burn rate than petrol or diesel so the only real explanation I can think of is the fact that the additives used have a much larger "heat of combustion" and although rise the octanic number of gas only in proportion to the amount used they actually do more in regards to the combustion heat. I think

 

[richydraper]

... I still see LPG as containing a higher burn rate than petrol or diesel...

LPG does burn faster which means its 'flame front' expands more rapidly... LPG in theory would run better at higher engine speeds due to this.

Internal combustion engines are designed to work optimally with, say for instance, a 95/98 RON petroleum fuel. it has a set burn rate which creates a flame front that the engine will be designed for... using different RON fuels will hinder the engines performance, smaller RONs the flame front will advance across the cylinder at a slower speed so the piston will be moving down as the flame front advances to the 'optimal' position.
Larger RONs flame front on the otherhand will advance too quickly across the cylinder reaching the optimal position sooner therefore putting extra stress on the internals this is effectively 'pre-detonation' or as some of you know it 'pinking' where the fuel is burnt too soon in comparison to the position of the pistons stroke

 

[Morty Mort]

Yeah yeah, I forgot to mention the economy. Mine doesn't go down by a liter but more of a .5 liter/100 km. Instead of 7.4 I may be able to reach 6.7-6.8. I can only get 6.2 or even 5.8 if I never go over 100 km/h and rarely stop for anything, but nevertheless, mine is a 1.8 so I should expect a difference.

It's not many years since we got 100 km/h allowed for some roads in Norway, and they are very few. 100 km/h (as you say) seems to be the 1.6 engine's magic limit aswell regarding fuel economy.

Anyway, the same trip with our Dethleffs caravan, easily reaches 1,2 l/100 km. So much for environmental friendly driving.

 

[vladof]

using different RON fuels will hinder the engines performance, smaller RONs the flame front will advance across the cylinder at a slower speed so the piston will be moving down as the flame front advances to the 'optimal' position.

This may be an explanation as to why they say to only use 95 Octane or above. Too low and you would use too much fuel and put too much stress on the engine, too high and you would do the same. But I guess that when it burns exactly how it should then the engine would run a little bit more efficient, thus the MPG increase we seem to see when using better fuel. This and, of course, you have a cleaner engine that will last longer.

It's not many years since we got 100 km/h allowed for some roads in Norway, and they are very few. 100 km/h (as you say) seems to be the 1.6 engine's magic limit as well regarding fuel economy.

Anyway, the same trip with our Dethleffs caravan, easily reaches 12 l/100 km. So much for environmental friendly driving.

Yes well we only have a 90 km/h speed limit as well but it's an unwritten law to only obey the speed limit on highways or towns/cities. Nobody will stop you if you go 130 km/h on a national road but nevertheless you're responsible for your safety, passengers safety and the other driver's safety if you hit them so I rarely go above 120.

Regular outside town roads limit: 90km/h
European Roads: 100 km/h
Highways: 130km/h

What model is your caravan out of curiosity? Is the Stilo struggling to pull it?

 

[neonglow]

Everyone knows that LPG is a lot worse than gasoline. You are right it's not just the RON that matters but it's a much more complicated ecuation in mixtures that would give the petrol more power. We have a lot of taxis in Bucharest that run on LPG, their cars are pathetically slow. (1.4 or 1.6 Dacia Logan). You should check out "Heat of Combustion" on Wiki to see what really gives the engine power.

Well I wouldn't say LPG is a lot worse it's a lot better at the end standing at the cash register Anyway it burns a lot cleaner, does not dillute the oil and opposed to what they say has a lower heat which is less stress for the internal components, besides the valves which lack the liquid gasoline cooling them. Are you sure the taxis in Romania run on LPG and not on CNG.. cause CNG burns slower than LPG and you'll need a turbo then Performance wise I don't find a difference running on LPG compared to running on petrol. But I wanted it configured that way so that it goes like before but burns slightly more. Next car will have this: http://www.vialle.nl/home.html?L=1 Have a look at the performance chart at the bottom

 

[vladof]

There are no CNG filling station in Romania so yes it is LPG. But anyway, I wouldn't do it because the can occupies a lot of the boot space and I hate that. There were Stilos with built in LPG support but I haven't personally seen any of them.

I would go for electric of hidrogen powered cars in the future if I have the dough for it. Gas prices are ridiculous and personally I'm sick and tired of seeing cleaner and cleaner cars when we could all just use an alternative which is much much better. Fossil fuel will be a thing of the written as one of the world biggest environmental mistakes in the history books, although I did help build all those nice arab cities.

Anyway, checking youtube for charts between petrol and lpg they are kind of the same so I guess we should all convert.

 

[neonglow]

There are no CNG filling station in Romania so yes it is LPG. But anyway, I wouldn't do it because the can occupies a lot of the boot space and I hate that. There were Stilos with built in LPG support but I haven't personally seen any of them.

I would go for electric of hidrogen powered cars in the future if I have the dough for it. Gas prices are ridiculous and personally I'm sick and tired of seeing cleaner and cleaner cars when we could all just use an alternative which is much much better. Fossil fuel will be a thing of the written as one of the world biggest environmental mistakes in the history books, although I did help build all those nice arab cities.

Anyway, checking youtube for charts between petrol and lpg they are kind of the same so I guess we should all convert.

You can go hydrogen, no problem, just find a bottle holding a pressure of 1000 times atmospheric pressure - the engine runs fine on pure hydrogen .. and you'll also need some hydrogen of course I never thought I would ever convert to LPG but I got sick and tired of these prices, I do 30000kms min every year and now I pay almost half of what I used to pay dor gasoline. As for the boot space I have mine fitted in place of my spare wheel, so the boot stays the same, the filler is in next to the petrol cap, so you can't tell it's been converted. You're very right about using petrol, there are two great movies on this topic: "Who killed the electric car" and "Peak Oil"

Anyway, checking youtube for charts between petrol and lpg they are kind of the same so I guess we should all convert.

I wanted to show you the chart of the Viale systems which inject ice cold LPG in liquid state and run much better than any petrol and cool the valves better than anything http://www.vialle.nl/lpg-producten/lpg.html?L=1

Back to the topic: I think @Richy best described what's the difference in engine operation between the different RON ratings.

 

[vladof]

Y As for the boot space I have mine fitted in place of my spare wheel, so the boot stays the same, the filler is in next to the petrol cap, so you can't tell it's been converted.

How much did you pay for the conversion? I have a space saving spare wheel which is brand new, was never used from 2002 until now, so I guess it's safe to say I can remove it and go for the cheaper alternative.

Also, how does this affect the MPG from the board computer? Does it always say you are doing a gazillion km/l or it works just fine but you always have the same amount of petrol in the car regardless of how much you drive it?

I'm sorry for being offtopic here maybe somebody could move this conversation to a new thread so we can discuss it there

 

[richydraper]

Back to the topic: I think @Richy best described what's the difference in engine operation between the different RON ratings.

that was one of things you learn in college and think you will NEVER EVER use in the real world... turns out 8 years later...

in addition, higher RONs give the same performance at higher altitudes as lower RONs at lower altitudes IIRC (i think thats the right way round).

its a bit like water boils at atmospheric pressure at sea level at 100*C if you go up in altitude the boiling point lowers to 70-80*C or less. if you pressurize the vessel the temperature at which water boils increases (thats why your cooling system runs at around 1bar/14 psi)

 

[neonglow]

How much did you pay for the conversion? I have a space saving spare wheel which is brand new, was never used from 2002 until now, so I guess it's safe to say I can remove it and go for the cheaper alternative.

Also, how does this affect the MPG from the board computer? Does it always say you are doing a gazillion km/l or it works just fine but you always have the same amount of petrol in the car regardless of how much you drive it?

I'm sorry for being offtopic here maybe somebody could move this conversation to a new thread so we can discuss it there

The conversion costed ~700 Euro: http://www.landi.it/layout.jsp?idz=60173&idtp=165&lang=3&idprodotto=6 That was the best and most expensive one for a 4 cylinder engine The LPG system has its own ECU which is connected to the car's ECU and recalculates the fuel injection timing for LPG. You should better read the description on their site. There are lots of options, you can run on both petrol and LPG, it automatically switches to LPG when some temperature is reached etc. When you run out of LPG it automatically switches to petrol, you can do emergency engine startups on LPG etc. You can also make it run faster than it does on petrol. No difference to petrol whatsoever, neither the car has changed in any way it's just that you pay half the price at the gas station and if travel to, let's say, Greece you can fill it up with both petrol and LPG and go in both directions without having to refill with some expensive Greek petrol The trip computer works just like before it calculates the range according to the fuel left in the tank and the current consumption it’s just that the range doesn’t really go down as the fuel level stays the same. It’s still showing the instantaneous fuel consumption although the injectors have been bypassed. If you buy a high quality sequential system you won’t have any problems. It’s the people who try and install 1 gen systems to old but computer controlled fiat engines that have problems, these use all of the sensors and the car’s ECU to create the mixture and advance the ignition.

Never been to the UK myself but I heard LPG conversions are pretty popular here, once watched on wheeler dealers how they tried to convert an old Land Rover

Edit: the biggest bottle you can fit in the spare wheel compartment is 40 litres which is has an usable volume of 80% (30litres). I get a range of min 350kms with a full bottle both urban and extraurban cause I drive >100km/h outside the city which gives me the same consumption as when driving in the city. Once I managed to do 420kms on a full tank of LPG but was driving very gently never exceeding 120km/h.