Regular or High Octane gasolene
Discussion
In the "old" days of mechanical igntion and mechanical distributors, there was only very limited control of timing. Therefore you either set the timing for regular gas (and got lower performance and gas mileage but no knocking) or for premium high octane gas and got better performance and gas mileage (but NOT at the same time!).
Modern cars have a knock sensor which controls the ignition advance. The ignition system will push the timing ahead until a knock is sensed and then will back it off. It will continually try to advance the timing as far as it can all the time. Higher octane gasolene resists knock and therefore should allow the timing to be advanced further than regular gasolene. More advanced timing gives higher engine output. Following me? Therefore, using premium gas in my (for example) Honda Accord will produce more power across the entire spectrum and better gas mileage overall (if I don't use the extra power by standing on the gas pedal more).
However, everything I read says using premium gas in a car designed for regular will not improve performance or gas mileage. Can anyone explain if using premium in an engine designated for regular will improve performance?
Modern cars have a knock sensor which controls the ignition advance. The ignition system will push the timing ahead until a knock is sensed and then will back it off. It will continually try to advance the timing as far as it can all the time. Higher octane gasolene resists knock and therefore should allow the timing to be advanced further than regular gasolene. More advanced timing gives higher engine output. Following me? Therefore, using premium gas in my (for example) Honda Accord will produce more power across the entire spectrum and better gas mileage overall (if I don't use the extra power by standing on the gas pedal more).
However, everything I read says using premium gas in a car designed for regular will not improve performance or gas mileage. Can anyone explain if using premium in an engine designated for regular will improve performance?
Haltamer, again back in the old days, increasing the advance by turning the distributor would make a notable improvement in performance. However, maybe modern cars are so well set up that the improvement would not be noticeable. And in response to "Toomany2CV", yes I am indeed stateside (New Jersey to be exact).
I frequently treat myself to 100RON when topping up my 156 GTA in Germany, and have admixed aviation fuel with plain cooking fuel elsewhere.
It might just be confirmation bias on my part, and I'm humming along the surface of a German autobahn after Belgian/Lux roads, but the car does seem to run smoother and feels a little bit more powerful. However, I have absolutely no hard data to back this up.
It might just be confirmation bias on my part, and I'm humming along the surface of a German autobahn after Belgian/Lux roads, but the car does seem to run smoother and feels a little bit more powerful. However, I have absolutely no hard data to back this up.
For a vehicle with a modern electronic engine control unit then higher octane fuel will give more performance. However from my experience over a number of cars:
- The improvement in performance won't be 'earth shattering' for NA engines. In fact, it's usually hardly noticeable.
- The improvement in performance can be quite noticeable for turbo engines.
- The cost reduction in improved fuel efficiency is likely to be marginal, if anything at all, when compared to the extra cost (particularly here in the UK) of higher octane fuel.
In other words - turbo engine, go for it; NA engine, don't bother.
- The improvement in performance won't be 'earth shattering' for NA engines. In fact, it's usually hardly noticeable.
- The improvement in performance can be quite noticeable for turbo engines.
- The cost reduction in improved fuel efficiency is likely to be marginal, if anything at all, when compared to the extra cost (particularly here in the UK) of higher octane fuel.
In other words - turbo engine, go for it; NA engine, don't bother.
DoubleD said:
TooMany2cvs said:
Over here, virtually everything has a basemap set up for 95RON, our vanilla fuel. 97/8/9 is available, but at a big price premium.
A big price premium? TooMany2cvs said:
DoubleD said:
TooMany2cvs said:
Over here, virtually everything has a basemap set up for 95RON, our vanilla fuel. 97/8/9 is available, but at a big price premium.
A big price premium? Burnzyb said:
Turbo cars benifit from higher octane fuels a lot more than N/A engines.
My E36 I6 2.5 Nat Asp benefitted from 98 RON over the standard 95 RON. Much smoother, better fuel consumption and more power. This was a 1998 built car, standard apart from the fuel. About 2 to 3 mpg improvement and smoother. Once I had done several comparisons over a year or two, I stuck with 98+ RON. The car’s knock sensor adjusted to the higher octane fuel.Garvin said:
For a vehicle with a modern electronic engine control unit then higher octane fuel will give more performance. However from my experience over a number of cars:
- The improvement in performance won't be 'earth shattering' for NA engines. In fact, it's usually hardly noticeable.
- The improvement in performance can be quite noticeable for turbo engines.
- The cost reduction in improved fuel efficiency is likely to be marginal, if anything at all, when compared to the extra cost (particularly here in the UK) of higher octane fuel.
In other words - turbo engine, go for it; NA engine, don't bother.
Not in my experience. - The improvement in performance won't be 'earth shattering' for NA engines. In fact, it's usually hardly noticeable.
- The improvement in performance can be quite noticeable for turbo engines.
- The cost reduction in improved fuel efficiency is likely to be marginal, if anything at all, when compared to the extra cost (particularly here in the UK) of higher octane fuel.
In other words - turbo engine, go for it; NA engine, don't bother.
Gassing Station | General Gassing | Top of Page | What's New | My Stuff