Downsized Turbo Engines and Fuel Octane
Discussion
Recently I've been on the hunt for a modern runabout. The most suitable seems to be a Clio 0.9 TCe or 1.0 TCe with 90-100hp but I have looked at similar cars from other manufacturers.
I test drove some and generally speaking they were very sluggish until the boost kicked in, at which point they were surprisingly lively.
So for most of the test drives the cars seemed dependent on the turbo and were on boost a lot of the time.
After one test drive I opened the bonnet and the tiny 1.0T engine was radiating an enormous amount of heat (I've never felt so much heat coming off an engine) suggesting it had been working very hard.
Surely those are the kind of conditions where an engine would benefit from a higher octane fuel? Not for more power, but to help the fuel burn better under prolonged hot, stressful, high load conditions.
People say 'it's fine, engines have ECUs and knock sensors and will retard the timing' but won't that be happening a lot with these small turbo engines that are running hot and at high load all the time?
Would we be better using 97-99 octane in these 1.0T type engines? Not for power gains but to help the engine run better and maybe last longer?
I test drove some and generally speaking they were very sluggish until the boost kicked in, at which point they were surprisingly lively.
So for most of the test drives the cars seemed dependent on the turbo and were on boost a lot of the time.
After one test drive I opened the bonnet and the tiny 1.0T engine was radiating an enormous amount of heat (I've never felt so much heat coming off an engine) suggesting it had been working very hard.
Surely those are the kind of conditions where an engine would benefit from a higher octane fuel? Not for more power, but to help the fuel burn better under prolonged hot, stressful, high load conditions.
People say 'it's fine, engines have ECUs and knock sensors and will retard the timing' but won't that be happening a lot with these small turbo engines that are running hot and at high load all the time?
Would we be better using 97-99 octane in these 1.0T type engines? Not for power gains but to help the engine run better and maybe last longer?
RVB said:
Surely those are the kind of conditions where an engine would benefit from a higher octane fuel? Not for more power, but to help the fuel burn better under prolonged hot, stressful, high load conditions.
No. High octane fuel in effect prevents fuel from burning "too well" in a way.Using a higher octane than recommended by the manufacturer is a waste of money. Octane prevents premature ignition. If you don't have that you don't need any better. Turbo engines are lower compression and all moderns turbo or not will have anti-pinking devices. Certainly on cars where high octane fuel is recommended, this can increase power too even if they can use any fuel, as the timing won't be dialed back to prevent pinking. This will lead to even more heat (even if insignificantly).
Oh and a 900cc turbo will probably be undrivable where high torque at low engine speeds is required, such as negotiating a very steep incline from stationary, for example leaving a parking space, without performing embarrassing burnouts. I very literally could not enter an old hillside village in Spain with a rental with the same engine. An absolutely undrivable POS anywhere other than the open road, that had to be parked outside the village.
996TT02 said:
Oh and a 900cc turbo will probably be undrivable where high torque at low engine speeds is required, such as negotiating a very steep incline from stationary, for example leaving a parking space, without performing embarrassing burnouts. I very literally could not enter an old hillside village in Spain with a rental with the same engine. An absolutely undrivable POS anywhere other than the open road, that had to be parked outside the village.
Interesting.Is the car a Captur?
996TT02 said:
No. High octane fuel in effect prevents fuel from burning "too well" in a way.
Using a higher octane than recommended by the manufacturer is a waste of money. Octane prevents premature ignition. If you don't have that you don't need any better. Turbo engines are lower compression and all moderns turbo or not will have anti-pinking devices. Certainly on cars where high octane fuel is recommended, this can increase power too even if they can use any fuel, as the timing won't be dialed back to prevent pinking. This will lead to even more heat (even if insignificantly).
Oh and a 900cc turbo will probably be undrivable where high torque at low engine speeds is required, such as negotiating a very steep incline from stationary, for example leaving a parking space, without performing embarrassing burnouts. I very literally could not enter an old hillside village in Spain with a rental with the same engine. An absolutely undrivable POS anywhere other than the open road, that had to be parked outside the village.
Wow. You sound like an expert.Using a higher octane than recommended by the manufacturer is a waste of money. Octane prevents premature ignition. If you don't have that you don't need any better. Turbo engines are lower compression and all moderns turbo or not will have anti-pinking devices. Certainly on cars where high octane fuel is recommended, this can increase power too even if they can use any fuel, as the timing won't be dialed back to prevent pinking. This will lead to even more heat (even if insignificantly).
Oh and a 900cc turbo will probably be undrivable where high torque at low engine speeds is required, such as negotiating a very steep incline from stationary, for example leaving a parking space, without performing embarrassing burnouts. I very literally could not enter an old hillside village in Spain with a rental with the same engine. An absolutely undrivable POS anywhere other than the open road, that had to be parked outside the village.
evil.edna said:
996TT02 said:
No. High octane fuel in effect prevents fuel from burning "too well" in a way.
Using a higher octane than recommended by the manufacturer is a waste of money. Octane prevents premature ignition. If you don't have that you don't need any better. Turbo engines are lower compression and all moderns turbo or not will have anti-pinking devices. Certainly on cars where high octane fuel is recommended, this can increase power too even if they can use any fuel, as the timing won't be dialed back to prevent pinking. This will lead to even more heat (even if insignificantly).
Oh and a 900cc turbo will probably be undrivable where high torque at low engine speeds is required, such as negotiating a very steep incline from stationary, for example leaving a parking space, without performing embarrassing burnouts. I very literally could not enter an old hillside village in Spain with a rental with the same engine. An absolutely undrivable POS anywhere other than the open road, that had to be parked outside the village.
Wow. You sound like an expert.Using a higher octane than recommended by the manufacturer is a waste of money. Octane prevents premature ignition. If you don't have that you don't need any better. Turbo engines are lower compression and all moderns turbo or not will have anti-pinking devices. Certainly on cars where high octane fuel is recommended, this can increase power too even if they can use any fuel, as the timing won't be dialed back to prevent pinking. This will lead to even more heat (even if insignificantly).
Oh and a 900cc turbo will probably be undrivable where high torque at low engine speeds is required, such as negotiating a very steep incline from stationary, for example leaving a parking space, without performing embarrassing burnouts. I very literally could not enter an old hillside village in Spain with a rental with the same engine. An absolutely undrivable POS anywhere other than the open road, that had to be parked outside the village.
RVB said:
Recently I've been on the hunt for a modern runabout. The most suitable seems to be a Clio 0.9 TCe or 1.0 TCe with 90-100hp but I have looked at similar cars from other manufacturers.
I test drove some and generally speaking they were very sluggish until the boost kicked in, at which point they were surprisingly lively.
So for most of the test drives the cars seemed dependent on the turbo and were on boost a lot of the time.
After one test drive I opened the bonnet and the tiny 1.0T engine was radiating an enormous amount of heat (I've never felt so much heat coming off an engine) suggesting it had been working very hard.
Surely those are the kind of conditions where an engine would benefit from a higher octane fuel? Not for more power, but to help the fuel burn better under prolonged hot, stressful, high load conditions.
People say 'it's fine, engines have ECUs and knock sensors and will retard the timing' but won't that be happening a lot with these small turbo engines that are running hot and at high load all the time?
Would we be better using 97-99 octane in these 1.0T type engines? Not for power gains but to help the engine run better and maybe last longer?
Just use whatever fuel the manufacturer states.I test drove some and generally speaking they were very sluggish until the boost kicked in, at which point they were surprisingly lively.
So for most of the test drives the cars seemed dependent on the turbo and were on boost a lot of the time.
After one test drive I opened the bonnet and the tiny 1.0T engine was radiating an enormous amount of heat (I've never felt so much heat coming off an engine) suggesting it had been working very hard.
Surely those are the kind of conditions where an engine would benefit from a higher octane fuel? Not for more power, but to help the fuel burn better under prolonged hot, stressful, high load conditions.
People say 'it's fine, engines have ECUs and knock sensors and will retard the timing' but won't that be happening a lot with these small turbo engines that are running hot and at high load all the time?
Would we be better using 97-99 octane in these 1.0T type engines? Not for power gains but to help the engine run better and maybe last longer?
Using SUL will offer no real benefit. It will not run better or last longer. It will not make any difference, because it will be tuned correctly to run on whatever they have recommended and under more wide and varied conditions than most of us would ever be able to replicate.
But equally, it will do no harm. So if it makes you feel better, fire away
stevieturbo said:
Zarco said:
I don't understand the issue with entering the village.
Off boost, driving off say up a steep hill, it would be so gutless it may be difficult for some drivers to make progress.I've never driven a small capacity turbo, but I've driven some s
t boxes in the past and always made it to my destination. Zarco said:
Such that one literally couldn't make it up the hill?
I've never driven a small capacity turbo, but I've driven some st boxes in the past and always made it to my destination.
Reminded me of this:I've never driven a small capacity turbo, but I've driven some s
t boxes in the past and always made it to my destination. https://www.motoringresearch.com/car-news/fiat-500...
Unfortunately the video link doesn’t seem to work anymore.
My wife drove a 2010 Clio 1.2TCE (100hp & 107lbft of torque) for 11 years & now has a Fabia 1.0TSi (110hp & 148lbft). Both was/is great on the Cotswold hills that surround our home. The extra torque of the Fabia is very noticable, particularly at lower revs, & it uses far less fuel.
My Leon 1.4TSi {(150hp) with 184ftlb of torque is even better.
My Leon 1.4TSi {(150hp) with 184ftlb of torque is even better.
Some of this will be driving 'style'.
I recently hired a Fiat 500 hybrid. Nicely put together and supposedly very economic. The hybrid part works remarkably well, seamlessly.
But I was driving to Paris, over 250km so the hybrid feature was really only in action in a couple of towns and around the airport. Getting up hills on the autoroutes was a little problematic.
Car had a 6 speed gearbox and to maintain speed I was occasionally down to 4th, at full throttle. Very highly geared and just lacks the torque unless you change down - a lot!
But then I also drive a 2CV, so I know a lot about struggling up hills!
I recently hired a Fiat 500 hybrid. Nicely put together and supposedly very economic. The hybrid part works remarkably well, seamlessly.
But I was driving to Paris, over 250km so the hybrid feature was really only in action in a couple of towns and around the airport. Getting up hills on the autoroutes was a little problematic.
Car had a 6 speed gearbox and to maintain speed I was occasionally down to 4th, at full throttle. Very highly geared and just lacks the torque unless you change down - a lot!
But then I also drive a 2CV, so I know a lot about struggling up hills!
We have a 453 smart with the 900cc turbo 3pot... Think it's the same engine.
When it's on normal fuel at idle it knocks something chronic and it hunts. 3pots are inherently imbalanced anyway, but it's nasty. It's a totally different car with high octane fuel.
Despite telling my wife repeatedly she puts any old st in it. She'd put red diesel in it if it were available at the pumps and cheaper 
When it's on normal fuel at idle it knocks something chronic and it hunts. 3pots are inherently imbalanced anyway, but it's nasty. It's a totally different car with high octane fuel.
Despite telling my wife repeatedly she puts any old s
t in it. She'd put red diesel in it if it were available at the pumps and cheaper Zarco said:
Such that one literally couldn't make it up the hill?
I've never driven a small capacity turbo, but I've driven some st boxes in the past and always made it to my destination.
Some people struggle down hills, nevermind up.I've never driven a small capacity turbo, but I've driven some s
t boxes in the past and always made it to my destination. I've no idea what the gearing on said car is like, clutch, power delivery etc etc, or drive ability.
But I have driven some cars so gutless, but with tall gearing that more clutch use that desired has been needed to get underway at times.
Really, small engined vehicles like that, with limited power, should have proper automatic transmissions to make better use of them. Auto's, whether DSG or true auto are miles better than anything from decades ago.
Although automated manuals are usually s
t. CVT always had potential...just nobody ever really seemed to get it right996TT02 said:
Oh and a 900cc turbo will probably be undrivable where high torque at low engine speeds is required, such as negotiating a very steep incline from stationary, for example leaving a parking space, without performing embarrassing burnouts.
Just to confirm: the many thousands of small turbocharged engine cars that have been on the roads for years are actually undriveable and cannot go up hills from a standing start? Hilarious, do you have any more gems for us?stevieturbo said:
Some people struggle down hills, nevermind up.
I've no idea what the gearing on said car is like, clutch, power delivery etc etc, or drive ability.
But I have driven some cars so gutless, but with tall gearing that more clutch use that desired has been needed to get underway at times.
Really, small engined vehicles like that, with limited power, should have proper automatic transmissions to make better use of them. Auto's, whether DSG or true auto are miles better than anything from decades ago.
Although automated manuals are usually st. CVT always had potential...just nobody ever really seemed to get it right
I almost got stuck once visiting relatives with a very steep driveway, and no runup.I've no idea what the gearing on said car is like, clutch, power delivery etc etc, or drive ability.
But I have driven some cars so gutless, but with tall gearing that more clutch use that desired has been needed to get underway at times.
Really, small engined vehicles like that, with limited power, should have proper automatic transmissions to make better use of them. Auto's, whether DSG or true auto are miles better than anything from decades ago.
Although automated manuals are usually s
t. CVT always had potential...just nobody ever really seemed to get it rightThe car had a 1.2 litre, naturally aspirated engine which had no torque at all below about 4,000 rpm, because of the cam & carbs required to get decent power.
I eventually got up the driveway, after about 4 attempts, by sidestepping the clutch at 7,000 rpm and wheel spinning all the way up.
It only took about 5 years for me to be forgiven for that, and a lot longer before it was forgotten.
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