View Full Version : Gas Mileage and Grades

10-21-05, 03:31 PM
I was wondering what kind of gas mileage other members are getting per gallon, and the grade everyone is using... My Escalade is 100% stock, no large rims, and I do a lot of highway driving and am getting 14.9 miles to the gallon on the middle grade of gas, plus (89 octane). The dealer told me upon purchase to use 93 octane, but I just found that wasteful since I only keep my trucks till about 60,000 miles...

10-21-05, 03:53 PM
There was recently a long post about this.... http://www.cadillacforums.com/forums/showthread.php?t=52892

10-22-05, 12:01 AM
In most vehicles running lower octane fuel will get you better mpg. The 10.1 6.0 liter engine will run smoother on a high octane gas though. I can only speak for myself, and I get around 14.1-14.6 around town running 87 octane fuel )pretty hilly roads). I recently switched to 89 octane to compare the two in terms of mpg and how smooth they run in my Lade. My engine doesn't knock as much on 89 as it did 87 octane.....I've found this to be true on the first tank.

It's anectodal experience, but I'll post any differences after running a couple of tanks of 89.

10-22-05, 02:41 AM
higher the octane fuel is more resistant to burning. in high compression engines this will prevent the fuel from poping off early (knocking). it will also produce more power due to the fact that the A/F mix will burn slower, longer
and more compleately. the ECM will control the knock, but to do this it will retard the spark and you will have reduced power. what you save in gas price you might loose in MPG, because you will have to give it more throttle to get the same result as some one running highher octane

10-22-05, 03:54 AM
11 mpg :thumbsup:
I use 89 always.

10-22-05, 06:25 AM
started off at 10.1 mpg when I just first got it. Its been about a month now and I recently have filled up with two tanks using 92 octane. I really cant feel the difference but my mpg when up to 10.8 mpg woohooo. Currently its at 10.5 because I only drive to and from work traveling about 10 miles round trip and it just stayed at 10.5:o. Hopefully soon when I install the volant cold air intake, borla dual exhaust and a computer programmer, I hoping it should do better on gas mileage...I hope

10-22-05, 11:01 AM
You only need 91 octane, were we live you can get 89 octane or 93 octane, so I run 93. In city driving I get 12.2, that is just city stop and go, on the highway I get as much as 19+, driving over 75 mph I get about 18. If you live high enough above sea level then 89 octane would be fine.