Increase MPG

There is only one guaranteed way to maximize fuel economy and it consists of having the vehicle as light as possible and driving it at its sweet spot in terms of MPG.

For my truck it gets the maximum MPG at 62 MPH and I drive it at 65 MPH most of the time. I could drive it at 75 MPH and burn 20% more fuel but to me that would be stupid. It seldom matters whether I get where I am going in 20 minutes or in 23 minutes.

I have decided that the 3 minutes saved is worth less to be than the cost of buying fuel for $1 more a gallon as that is the net effect of speeding, something that most people fail to grasp.

There is an entire industry though that will happily take your money and promise you big improvements in fuel economy. Even if they worked the breakeven point does not work for me. I saw a $500 tuner for my truck and if it did increase the fuel economy as much as was claimed the breakeven or point where I would recoup the $500 would be at 25,000 miles.

camperpaul wrote:

donn0128 wrote:

Dannyabear1 wrote:
THERE IS NOTHING THAT WILL INCREASE THE MPG On A 6.0 gm

Well, there are two things.
Slow down,
And......
Reduce weight!

I recently purchased a "new to me" 2011 6.0L GMC Sierra 2500HD Denali.
The previous owner never reset the trip odometer or the MPG calculator.
He got an average of 7.1 MPG for the 38,000 Miles he drove this truck and never towed a trailer.

In the past few months, I have driven it ~4000 Miles.
Without my trailer, I get ~14 MPG.
With my 7700 lb. trailer, I get ~9.5 MPG.

It's mostly how you drive ...

I had the same experience with my 2009 F250 5.4L. The previous owner never reset the trip computer and had put about 14,000 miles on it. The computer showed an average of 12.2 mpg, and he never towed or hauled anything (no scratches in bed or in tow receiver). I tow my toy hauler, and my utility trailers, and all around commuting, and always get at least 14.2 mpg.

I accelerate sensibly, slow down smoothly, and anticipate lights and stops, and drive anywhere from 55-70 on the highway. You can get at least 2 mpg better just by driving sensibly.

No concerns. Just an observation.

jfkmk wrote:
400 for a half mpg is a pretty poor investment.

Not when you tow approx. 5k miles a year! It adds up quick. And I didn't buy it for the fuel savings, I bought it for the increased towing performance! The .5 mpg is a plus. And in reality .5 mpg is pretty significant when you were getting 6.5 mpg! But thanks for being concerned about my finances! :B

400 for a half mpg is a pretty poor investment.

I`m running a 5 Star SCT programmer. I gained .5 mpg towing. yes it cost me $400 for the tuner, but the towing ability was also greatly improved!!!

I`ve also heard good things about Black Bear for GM gas trucks!

gmcsmoke wrote:

chevor wrote:
Drive slower, and highway tires aired way up.

so running a $250 tire at 80 pounds 24/7 is your way of saving money?

Why not? I do!

"" It's mostly how you drive ... """

From what I read a lot of people have accomplished significant improvements in MPG by using a ScanGauge 2 or a Scangauge E which allows them to closely monitor instant mpg and average mpg closer than the onboard computer on their vehicles and change their driving habits.
Also it allows for scanning any cel's that may effect performance of their vehicle.

Mr.Beebo wrote:
I'm at 10.5 mpg in town driving, 10 pulling a flat trailer and 9 pulling an enclosed cargo trailer (less with wind). Driving 60mph with a 10 mph tail wind this week I managed 14 mph over a tank and a half of gas. Most of the time on the highway it is 12-13.

The trucks computer controls everything. I can drive as gently as possible and it won't make any difference. I may gain a little mileage swapping out to a less aggressive tire, but that is about it. It is all about physics at this point-if GM could get more out of the truck, they would have done it.

They just need to dust off that 100 MPG carburetor from the 70's...lol

And to answer the OP's question, I've done it on an '11 2500 Suburban with the same engine, and I could only tell a small difference. I run an aftermarket intake and a B&B cat back exhaust with a Diablo tuner. I can tell by SOTP that it has a little bit more power, but fuel economy is only like 1 or 2 mpg better. That's about as close as any of my setups are, to what you have.