20 mpg?

[Fordubishi]

Ethanol is crap.... It has less energy then none ethanol and you will use more in the long run then with standard gas. It also eats rubber and will loosen rust that has built up in the tank over the years. This will cause fuel filter,carb jets and bowl to fill with rust.

Higher octane is not needed for an engine with 8.5:1 or lower compression with out boost, and no you will not get better mileage running 91 over 87 on a none computer controlled engine (Timing) as the engines now a days will increase timing till it knocks then back off the timing. On a higher compression engine or boosted you will need to run a higher octane so they don't ping under load. My 2002 F-150 I use 87 octane as the engine is only 8.5:1 compression but the D50 is running 11:1 and the bastard pings like a mother unless I run 93.

If you run 91 you can advance your timing up before it pings and it might help with the MPG and give you a little extra power.

[BradMph]

Ethanol is crap.... It has less energy then none ethanol and you will use more in the long run then with standard gas. It also eats rubber and will loosen rust that has built up in the tank over the years. This will cause fuel filter,carb jets and bowl to fill with rust.

Higher octane is not needed for an engine with 8.5:1 or lower compression with out boost, and no you will not get better mileage running 91 over 87 on a none computer controlled engine (Timing) as the engines now a days will increase timing till it knocks then back off the timing. On a higher compression engine or boosted you will need to run a higher octane so they don't ping under load. My 2002 F-150 I use 87 octane as the engine is only 8.5:1 compression but the D50 is running 11:1 and the bastard pings like a mother unless I run 93.

If you run 91 you can advance your timing up before it pings and it might help with the MPG and give you a little extra power.

Don't forget the water it collects. Ethanol is the #1 killer of 2 stroke boat motors collecting moisture and ruining the internals of the engine. This additive is a total scam on the public and destructive to all internal combustion engines. Search your local area for fuel stations that do not yet use this product. Your mileage increases and your engine last longer without this crap.

I have to agree with Merrill also, I have read many articles about octane and cars nowadays only require higher octane if your pinging and knocking. Then again if you have to climb in octane more then the manufacture requires, there is something wrong with your engine. In the old days, Octane helped, I agree to this also, but the biggest helper was that wonderful metal, LEAD. Oh how I miss that stuff in my engines. Octane only will help to a point then it starts to make things worse. Start burning things in your engine and getting hot spots among other issues. If your not running high performance, higher octane is usually a waste of cash if your not getting engine pings. There is one more thing that is good though. Some higher octane fuels carry detergents that clean your engine. Chevron use to have good cleaning properties in their fuels and if not mistaken their premium was the grade that they used to push detergent fuel additives. So, in tis case a higher octane would benefit your engine I'm sure.
Cars now are not like cars we use to have. Feeding and engine it's own crap is what we deal with today. Keep shoving that exhaust back in it's mouth until it's all just clean air coming out, lol.
What I noticed from the earlier years of cars to now is this. Come to a traffic light and watch the idling steam out of the exhaust pipes in the morning. It just barely flows out maybe a couple inches from the tip of the pipe and then disappears. In the earlier years, exhaust pipes would be thrusting that exhaust out and pulsating so hard it would shoot a foot or more out the tip of that pipe before it would loose resistance and flow away.