programer for a gas truck?

[96GST16g]

i recently have purchased an 03 gmc with a 6.0. just kind of wondering if the programmers would give me a great jump in performance and mpg if wanted. IO know abunch of people with desiels and i know i wont get the results they do just hope to get better than 8 mpg its lifted with big tires

[Kevin 1G Drummer]

6.0, lifted with big tires and you're concerned with mpg? Good luck... Even with a tuner you probably won't see anything better than 10mpg.

[96GST16g]

i forgot to also mention to change the shift points and line pressure..

[JET]

Most of them suck, get a new chip/flash from one of the guys out there, Wester's is a big one.

[Shane@DBPerformance]

Most gas tuners save gas by changing the trans shifting. It's hard to save fuel on a gas vehicle that already has working o2 sensors.

[niterydr]

HP Tuners is an option for modifying the trucks. The torque management program and lean fueling actually typically hurt MPG if you have a foot that needs power "now" and eases up later as you are on it longer.

My 2500HD with larger tires, drop in filter, and a hp tune tweak gets 12mpg city, as high as 16 on the highway. Truck has 113k on it and features the extended cab with the long box. (ECLB). I tuned it around 93k.
I have the 6.0 LQ4 and the 4L80E with 4.10 gearing.

However, the "unlocked" power is nice.

[96GST16g]

i basically have the same truck minus long box i love the truck but hate the econ. whatd you all have to do to tune it?

[96GST16g]

meeeeatty tires

[niterydr]

Originally Posted by 96GST16g

i basically have the same truck minus long box i love the truck but hate the econ. whatd you all have to do to tune it?

I own HP Tuners VCM Suite so it wasn't much more than:
-Scan Truck and pull map
-Purchase Credits
-Tune truck

I haven't messed with wot power and timing as my engine modifications aren't significant yet, and frankly I haven't had time to find that last little bit. If I threw a wideband on it, it would be done, just to lazy.

I did adjust transmissions shift points, and a variety of torque management and fuel trims to bump the mileage about 1-2mpg on average and much better throttle response.

I did the same treatment to a local 5.3 Avalanche to help him for towing his camper. Much better throttle response and better mileage as the tune suites his driving style. Plus hopefully his 4l60E will hold on longer with the transmission adjustments.

My truck has the 4l80E, so its damn near bulletproof in most stock applications.

The 12/16 isn't automatic, I have to work for it. Light throttle application stop light to stop light and using my cruise control on the highway helps. As much as this long box loves to cruise back roads at 80-90mph up in the sticks, mileage is much better at 55-65.

[96GST16g]

how much would you say you have stuck into it?

[niterydr]

the HP Credits were $100. I need to pick up a universal wideband for tuning other cars anyway, so I won't count that cost.
Filter was $40 ish?

I have a 1/2 dozen hours into tweaking/researching/reviewing logs so far, more to come.

[jrohner]

You have the 6.0 gas hog, you have big tires, you have a lift kit. All are strikes against you for gas mileage, and now you're wondering what to do to get better mileage? Maybe you should start pulling a big ass trailer while you're at it to get even worse mileage...

[jrohner]

Get rid of the lift kit. Get rid of the big tires.

[JET]

Throw some 3.73's in it if you have 4.10's. Our Denali XL gets about 17 on the highway at 70. Normal driving is mid 15's to 16, not bad for a 325hp 6.0 than can haul 7 people in comfort. I might have to come see you about a tune Swanny, the new tranny shifts a little hard from 2-1 and more mpg is always better.

[Shane@DBPerformance]

Don't go and delete EGR also, that will make it even worse.