View Single Post
Old 02-19-2009, 03:53 PM   #1 (permalink)
Rolling conundrum
Join Date: Feb 2009
Location: Madison, WI
Posts: 12

Yota - '99 Toyota 4Runner Limited
90 day: 19.44 mpg (US)
Thanks: 0
Thanked 1 Time in 1 Post
87 octane and retarded timing

I have a 2001.5 Passat wagon with the 1.8T engine. It calls for 91 octane or higher. For the past year or more, I have been using 87 octane, as the car seems to run just fine on it (no pinging). I rarely challenge the turbo (i.e. accelerate hard), and I haven't had any fuel-related issues.

However, I've been reading about how the computer will adjust timing to compensate for the easier-to-ignite low octane fuel, and how this can effect FE.

Since "premium" (I hate the fuel "grade"'s so misleading) costs on average 20 cents per gallon more than "regular", am I offsetting any savings at the pump for a loss in FE? What I mean is, am I coming out even, or am I doing worse by running lower octane than what is recommended?

Since gasoline is so cheap right now, I have no problem paying $2.20 for high octane...but when it was $4.50, for some reason I balked.


  Reply With Quote