Does This Sound Right?

tooch420 · May 30, 2011

Ok, My first question would be, what is my mpg out of the factory for my 06 GMC Sierra 2500HD with the 6.0? The reason I ask is because my mpg is averaging about 9 or 10 mpg...which sucks.

All I've done (well mostly) is do m ods to improve mpg...I've removed nechanical fan for set of electric fans, new K&N intake and dual Magnaflow exhaust, E3 plugs with Granatelli wires, and Diablo 93 oct tune.

On the down side, I've increased tire size and put leveling kit to raise and fit tires.

But after all that I should at least be little better mpg than stock, right?

Knowklew · May 30, 2011

bigger wheels and tires plus a lift....there's your mpg problem.

if you want better mileage put smaller less aggressive tires on.

I am suspect of the E3's and anything that has to do with Granatelli...just my .02

WilliamBos · May 30, 2011

bigger wheels and tires plus a lift....there's your mpg problem.

if you want better mileage put smaller less aggressive tires on.

I am suspect of the E3's and anything that has to do with Granatelli...just my .02

I agree on both counts. Pitch the E3's, put AC Delco plats/GM wires back on.

Why the tune, and switch to 93?? The engine was built for 87 octane, leave it at that.

JMHO.

Carder09 · May 30, 2011

Yeah same on the last replies, the tune to 93 doesnt help gas mileage at all, the grade of that gas actually takes more energy to activate, but gives a better compression for performance, so less octane quicker activation. or something within those limits lol.

tooch420 · May 31, 2011

Yeah same on the last replies, the tune to 93 doesnt help gas mileage at all, the grade of that gas actually takes more energy to activate, but gives a better compression for performance, so less octane quicker activation. or something within those limits lol.

I got worse gas mileage with the 87 tune...

Carder09 · May 31, 2011

Yeah same on the last replies, the tune to 93 doesnt help gas mileage at all, the grade of that gas actually takes more energy to activate, but gives a better compression for performance, so less octane quicker activation. or something within those limits lol.

I got worse gas mileage with the 87 tune...

What kind of "tune" are you talking of? higher octane of gas does not increase mileage whatsoever, there have been several researches against this and all say the same thing, higher octane helps zero in mileage, and if it does help, you need your car checked.

http://www.state.mn.us/mn/externalDocs/Com...OctaneFacts.pdf here is one of the hundreds of sites that state the same thing about higher octane gas...

cghbuilder86 · May 31, 2011

The things you did to improve mpg probably did little to nothing. Whats killing you is your leveling kit and bigger tires.

tooch420 · June 1, 2011

The things you did to improve mpg probably did little to nothing. Whats killing you is your leveling kit and bigger tires.

I was afraid you all would say that...I knew they would but I thought the improvements would more than weigh that out. And the Diablo Predator tune is supposed to give better fuel economy and performance.

tooch420 · June 1, 2011

LET ME ASK YOU ALL THIS....WHAT IS THE MPG OUT OF THE FACTORY FOR MY TRUCK???

Mckenzie · June 1, 2011

Dont feel bad my truck gets about 10.5-11 mpg around town and maybe 15 if im lucky driving like a grandpa on the I-state

MikeNH · June 1, 2011

LET ME ASK YOU ALL THIS....WHAT IS THE MPG OUT OF THE FACTORY FOR MY TRUCK???

They don't rate the HD trucks but I'd bet 10-12 maybe in city driving and 13-15 highway depending on axle gears. There's a 6.0/HD gasser thread around here somewhere.

old-chevy-dude · June 1, 2011

The things you did to improve mpg probably did little to nothing. Whats killing you is your leveling kit and bigger tires.

I was afraid you all would say that...I knew they would but I thought the improvements would more than weigh that out. And the Diablo Predator tune is supposed to give better fuel economy and performance.

LOL.. no offense, but I have yet to see a tuner give better MPG.. why? because with better performance your foot is it in more and as a result your MPG goes down..

Car Manufacturers spend MILLIONS in R&D to produce a vehicle that meets the very strict EPA and MPG requirements, there is NOTHING that you can add to a vehicle after the fact that will increase your MPG, I don't care what any marketing advertisement on some products box says..

The only way to meet or slightly exceed the EPA stats on the Window Sticker of any vehicle is driving habits and road conditions..

if you jack rabbit from light to light, drive 10 plus over the speed limit, change lanes and zip in and out of traffic speeding up and slowing down constantly, and drive like Mario Andretti just to get to your destiation 5 seconds sooner, your MPG will suffer.

Only true way to maintain decent MPG especially in a 6,000 - 8,000 pound truck is to:

accelerate slowly, maintain consistant RPMs (not Speed, RPM's) while cruising, coast when you see stale green lights or upcoming red lights, maintain a 55 - 60mph speed on the highway keeping the RPMs as low as possible, driving on flat (not hilly) roads, and being gentle as possible on that gas pedal under any and all circumstances..

I also avoid drive-thrus that is an MPG killer for sure (car just idling for 10 minutes or more in a DT) plus I have found going inside is usually faster than waiting in line at a DT anyway. I also turn off my ignition at long red lights, especially if I arrive as it turned red.

I can't speak for your 6.0L but my 5.3L with AFM is averaging 18.5 - 19.5 mpg because of my driving habits, and I have seen it drop to 15 mpg when I decide to be a little heavy on the peddle..

cghbuilder86 · June 1, 2011

I can never find factory EPA numbers for the 2500-3500 HD's They may be out there but hard to find. I guess they assume that it is bought with a working purpose and people wouldn't be too concerned. I've always heard 12-13 for a 2500 6.0. Thats why I drive a 5.3 1500 and go 48 mph to milk that gas mileage. Maybe just try slowing down and coasting as much as you can. If a few mpg's are a big deal go back to stock tires and height.

old-chevy-dude · June 1, 2011

prior to 2011, the 2500 and 3500 series were exempt from EPA testing, hence why there are no numbers:

http://www.fueleconomy.gov/feg/which_tested.shtml

wages999 · June 1, 2011

My brothers stock 2500HD (reg cab, 4x4, 4.10's) with the 6.0 could not get better than 14 and that was all highway, empty. I think he averaged 12, but really didn't tow much and babied the throttle as much as possible. A neighbor has the same set-up in his truck and his truck won't get over 14 (all highway). He is a farmer and has a lot of short trips. He said he was lucky to get 10 around town.