View Single Post
Old 02-13-2013, 01:06 PM   #46 (permalink)
rmay635703
home of the odd vehicles
 
rmay635703's Avatar
 
Join Date: Jun 2008
Location: Somewhere in WI
Posts: 3,882

Silver - '10 Chevy Cobalt XFE
Thanks: 500
Thanked 865 Times in 652 Posts
Quote:
Originally Posted by razor02097 View Post
Unless your vehicle pulls timing when you use lower octane fuel you will not benefit from using a higher octane. Period. If the engine runs with full advance on 87 octane, using higher octane fuel will make zero difference.
Most vehicles now days are 10:1 + compression, my vehicle will run full advance on 87 octane but bucks at low RPM and then pulls timing until my rpms increase.

Most new vehicles benefit from higher octane due to the way they can alter timing (OBDII anyone) but the benefit may not be significantly better FE, for me it was about 2mpg going from 87 e10 to 89e10, but on 48-52mpg that is only about 4% or so. It was about the same differance as going from 87e10 to 87e0
Cheers
Ryan
  Reply With Quote