Real Gas vs. Ethanol Gas Question

[mtnguy]

Originally Posted by TheSasks

Chap,

Some vehicles do get better mileage towing running higher octane, we use mid grade 89 if we can get or high if not. The reason is simply the higher octane keeps the engine from detonating under load and which causes the computer to richen the mixture and pull timing out so you get less power and more fuel burnt.

Makes sense.

[jimh]

Originally Posted by TheSasks

Chap,

Some vehicles do get better mileage towing running higher octane, we use mid grade 89 if we can get or high if not. The reason is simply the higher octane keeps the engine from detonating under load and which causes the computer to richen the mixture and pull timing out so you get less power and more fuel burnt.

that's it. octane rating is a ping measurement. in the very old days, they put lead in to smooth out the explosion. not sure what ethanol will do. it is interesting on how some additives will increase octane in small amts but go the other way in larger amts.

[DF5.4]

I'm also using the Superchips tuner. The tow program is tuned to run at least 91 octane. I always use that when I tow and I still got better MPG.

[TheSasks]

Originally Posted by DF5.4

I'm also using the Superchips tuner. The tow program is tuned to run at least 91 octane. I always use that when I tow and I still got better MPG.

I would expect you would. So at the very least their programmer seems to work as advertised for you. I have been mulling over getting one for our truck but have not seen anything too conclusive to say it was worth it for a daily driver/TV.