what is the difference between octane91 & octane95 in terms of fuel consumption.?

Answer 1

There is no difference. The octane ratings just indicate how well that particular fuel will burn (without premature ignition pinging) in a high compression engine. Mileage is no different.

Answer 2

That is a big question. On a N/A car with about 9.5:1 compression and aluminum heads. Not much. Heres the thing though. By running 95 in a car that doesnt need it you dont burn all the fuel, thusly you are not getting closer to 100% volumetric efficiancy. By running 91 without detination you are. On the other hand if the engine has an agressive tune then you need the 95 to stop detination due to the lean condition you would have. But at that point you would be running about 12.5:1 compression. However if your car is carbureted then you are computer and have to give it a good tune. With that in mind you have to use what fuel you tune it for. But go with the 91 becuase you really dont need 95 unless you are running like 14:1 compression on a carbed car. I know this is a bit confusing but I hope it helps.

Answer 3

No difference in fuel consumption. The higher octane prevents pre-detonation in a high compression engine. Read your owner's manual and see what octane the manufacturer recommends.

Any factory-built car should not need an octane rating higher than 91. The 95 would be for custom built high compression engines.

Answer 4

In terms of fuel consumption: zero to .01% improvement with 95.

(not enough to make it worth the extra money)

Answer 5

no not fuel economy just performance on a high compression motor.

Answer 6

mechanic my whole life.

I don't know for sure.

cars don't have octanes test,It spend the fuel by metering.

But the computer claim,she know when and how accelerate which end up in better "octanes more millage."

Hum.........

Answer 7

http://en.wikipedia.org/wiki/Octane_rating#Effects_of_octane_rating