Higher octane
Senior User
Joined: Mar 2005
Posts: 173
Likes: 0
From: TX
I've not found any increase in fuel economy with higher octane fuels; I believe in burng the lowest octane fuel that doesn't allow pinging. Any octane higher than that is a waste of money and energy (btu content).
Hotshot
Joined: Mar 2007
Posts: 10,101
Likes: 40
From: Pa
If you have detonation with 87 octane you have issues that need to be corrected. Since some higher octane "premium" gasolines have less ethanol content in some areas, (over 87) yes you could see some possible mpg increases. I'll only run higher octane fuel if I have a tune to to take full advantage of it.
Cargo Master
Joined: Jan 2007
Posts: 2,243
Likes: 79
From: Roman Forest, TX
I never saw any increases, but I was running higher octane only with the tow tune that required it. Any other time there was no differenct. And with up to a .30 cent difference in price, it's definitely not worth it.
Postmaster
Joined: Apr 2006
Posts: 3,524
Likes: 2
From: CA Bay Area
I've been driving vehicles with different octane requirements on different fuel and here are my conclusions:
-putting lower octane in high-octane engine will make you go slower. Slower speed = fuel saving. Would the engine run at the same accelerations -the fuel consumption would be higher.
-having low octane engine and facing mountain driving I was always filling up with premium. When on lower octane the engine would ping and I had to downshift -on higher octane I could keep on going on higher gear. That not only got me there faster, but higher gear saved some fuel. I do calculate mpg at each fill up, so do have solid confirmation for my experience, although differences are too small to make a big deal.
-putting lower octane in high-octane engine will make you go slower. Slower speed = fuel saving. Would the engine run at the same accelerations -the fuel consumption would be higher.
-having low octane engine and facing mountain driving I was always filling up with premium. When on lower octane the engine would ping and I had to downshift -on higher octane I could keep on going on higher gear. That not only got me there faster, but higher gear saved some fuel. I do calculate mpg at each fill up, so do have solid confirmation for my experience, although differences are too small to make a big deal.
