Better Mileage?

[thaihedgehog]

Just wanted to know which type of petrol will improve the petrol mileage in my car, the car is 10 years old and i would think any petrol could be added?? i don't care about speed and preformance, just want more miles to the gallon. Cheers

[Thaiboxer]

From what people have said, gasohol will not get better mileage than regular petrol. It contains less energy per unit and therefore gets used up faster to produce the same amount of work. Being that the price of gasohol is not much less than petrol 91, this probably cancels out the benefit of using it. This leaves 91 petrol vs. 95. The 95 petrol has a higher flash point so it's necessary for engines that produce more pressure in the cylinders (high performance cars like Porsches for example). With regular cars, I haven't seen any difference in mileage between the high octane petrol and lower octane petrol. In my current car, there is NO difference in mileage so I just go for 91 since it's cheaper. Perhaps you can try filling up from empty and doing some simple calculations, then factor in the difference in price/liter to see what's best for your car. Good luck!

[Upcountry]

With your engine tuned up according to spec, you engine will get the best performance and fuel economy with the gas it was designed to use. It's not good, generally to use 91 in a car that was designed for 95, and I think worse to use 95 in a car designed for 91.

I agree with Thaiboxer, ethanol will be less efficient. Another bad thing about ethanol is that it will tend to evaporate from your 10 year old car's tank. That's one reason why I'll put off using ethanol as long as possible. It may okay for new cars, but in general it's recommended that car owner's fill up jut prior to using the car, not before parking it (especially for a while).

[culicine]

With your engine tuned up according to spec, you engine will get the best performance and fuel economy with the gas it was designed to use. It's not good, generally to use 91 in a car that was designed for 95, and I think worse to use 95 in a car designed for 91.

How the car responds will depend on the engine itself. I'm led to believe the accord 3.0 will respond to 95, (something to do with a knock sensor), but the other honda's wiill not respond to 95. I've never used regular 95 in my civic 2.0, so I don't know. I do know when the fuel attendant accidentally put in gasohol 95, it ran more poorly and was relatively more expensive to run. The mileage was quite poor. Better to get a focus if you wanna run ethanol. Better still buy the ford focus diesel:)