Best MPG, AFM & Important Fuel information for GM engines..

[BG1988]

I have been Testing Shell Vpower VS Chevron (aka Texaco, and Caltex stations)
Both using 91 Octane fuel (highest unless you pay for 100 octane unleaded racing fuel at $9.49 a gallon)

looks like so far Shell Fuel is a total loser.. so far..

on June 9th I started using Shell vpower fuel 91octane

you can see the downward Slope on my Fulley..
I'll be running a Freeway test(on Saturday ) but based on the results so far I doubt I'll tick passed 20-22mpg where normally i can get 24-27mpg

http://www.fuelly.com/car/chevrolet/tahoe/2008/brent88/905265/fuelchart


I noticed V4 mode being used way less I also find it hard to stay in V4 mode with the shell fuel..

 

[kbuskill]

Lew, from Diablew, is who did my custom tune for me on my Burb. He told me specifically when I was recording my logs to send to him for the tune...

NOT TO USE SHELL or any of the no name mom and pop stations due to poor fuel...

He told me specifically to use Mobil fuel.

Not that he is the be all, end all in fuel knowledge but when you tune as many vehicles as he does and see as much live data as he does I guess you kinda get a feel for what's good and what's not.

I use Mobil pretty much exclusively now unless I am some where it's not available.

 

[BG1988]

Lew, from Diablew, is who did my custom tune for me on my Burb. He told me specifically when I was recording my logs to send to him for the tune...

NOT TO USE SHELL or any of the no name mom and pop stations due to poor fuel...

He told me specifically to use Mobil fuel.

Not that he is the be all, end all in fuel knowledge but when you tune as many vehicles as he does and see as much live data as he does I guess you kinda get a feel for what's good and what's not.

I use Mobil pretty much exclusively now unless I am some where it's not available.

Yes I'm going to quit the test and start testing Mobil fuel for a month....

The Shell test is deemed a failure..

even thought the mobil station is slightly further away...

Chevron is in the top spot..

my next fuel up is on the 22nd i expect it to be about 11 gallons with whats currently in the tank (full tank)and the mpg i'm getting..

shell is pretty clearly a loser.


but i'll fill it up with Mobil Exhaust Fluid

 

[swathdiver]

For our vehicles around here, we have the same experience. You can count on Shell to deliver less economy than the competition. Chevron is tops but hard to get. Mobil is second best followed by Sunoco. But this LS runs best on about an E20 mixture, between 18%-22%, whereas it delivers its best economy.

The experiences (gasoline) mentioned above rang true 5 and 10 years ago with our other vehicles too. If memory serves, we switched off Shell for our Buicks in the early 1990s for Chevron and Mobil.

 

[BG1988]

For our vehicles around here, we have the same experience. You can count on Shell to deliver less economy than the competition. Chevron is tops but hard to get. Mobil is second best followed by Sunoco. But this LS runs best on about an E20 mixture, between 18%-22%, whereas it delivers its best economy.

The experiences (gasoline) mentioned above rang true 5 and 10 years ago with our other vehicles too. If memory serves, we switched off Shell for our Buicks in the early 1990s for Chevron and Mobil.

Well I like to update it we have good weather conditions for testing


it averaged 25.6MPG according to the DIC over 160 miles..(it was pretty accurate with in 0.1 miles as I had reset it before the trip)
with Driver side A/C on and AFM is back to working as normal..



I'm willing to let shell back to testing i'll fill it up tomorrow and we can watch the fulley log average.. i just did not like the initial mpg drop and no AFM...
(it could have been caused by the previous issues I had)
do you think I should let it have a pass this time and continue?

 

[swathdiver]

do you think I should let it have a pass this time and continue?

Sure, run it again and give a good test.

 

[BG1988]

Sure, run it again and give a good test.

I put in mobil


but i'm going to drain the tank and fill it up on sat or sunday with mobil

 

[Doubeleive]

Aah must be nice to just cruise the speed limit, lol

 

[BG1988]

Aah must be nice to just cruise the speed limit, lol

i need to get another rim before i can speed it's Bent starts wobbling at 70mph and get worse as the speed goes up


I have to make my suv last I mean i got money to get another but I'd like to keep it at lest 7 years... or 155k miles (my break even point on fuel savings) vs the regular tahoe


after only 5,000 miles I saved almost $838 on gas vs normal Tahoe @4.199/gallon

I speed a lot 120MPH was the FASTEST i went NOT in my car though

Rental minivan from LA to Phenox back to LA

it had a wimpy 4 banger though.. 23MPG was the average
2018 Dodge Grand scare-a-van

25 highway is the EPA rating Not too bad for 100+MPH

 

[Doubeleive]

i need to get another rim before i can speed it's Bent starts wobbling at 70mph and get worse as the speed goes up


I have to make my suv last I mean i got money to get another but I'd like to keep it at lest 7 years... or 155k miles (my break even point on fuel savings) vs the regular tahoe


after only 5,000 miles I saved almost $838 on gas vs normal Tahoe @4.199/gallon

I get terrible gas mileage, it's because I have a heavy foot, I don't feel there is enough of a mileage difference in any brand of gasoline to justify paying more for a "name" brand so i usually stick to Arco or quick stop because of the lower price and if I am in the area I may fill up at costco, just doesn't make sense or (cents) to pay more or to drive out of my way to save .10 cents a gallon either, I use a arco business gas card so no extra .35 cent fee on every fillup or i will use gasbuddy for other stations and save .5 cents off a gallon which is only a dollar saving but still better than nothing, They tax us pretty good in Comifornia, I would say the gas here is easily a 1.00 more a gallon than national prices