What can I expect?

[blairboy3]

I've got a 2002 Tahoe 4x4 w/ 5.3l V8 getting around 15mpg average.

I'm planning on installing some Edelbrock headers, a dry filter cold-air intake, & maybe a throttle body spacer (w/ the nitrous ports... I lika the juice!). Everything else being stock, what kind of MPG & HP gains can I expect using the DiabloSport tuner?

Yes... I know how to keep my foot out of it. The nitrous comment is just a thought, I have it on my 68 Plymouth & it's VERY fun!

[blairboy3]

Well, luckily... this is my wife's car. She drives much better than I do

And, more than likely the nitrous will not go on the car for that reason... kids & car seats & all that stuff! So, I guess it'll be worth the upgrade. How much tweaking does the 87 Octane tune need?

Thanks!

[ches111]

You would just need to follow the stickys on this forum to set up your LTFTs or Long Term Fuel Trims.

After that the 87 Tune is pretty stout..

[blairboy3]

There are a couple guys w/ 6.0's getting 17(mixed) & +/-21 (freeway)

http://www.diablosport.com/index.php?na ... pic&t=8276

Is it rediculous to expect to see the same or a little better from my setup w/ the tuner?

I'm COMPLETELY new to all this tuner stuff. I'm used to the old school stuff. My Plymouth has a 500" engine w/ nitrous & low gears. It get's tuned w/ a screw driver & sockets. The only thing that touches it that remotely resembles a computer is my digital timing light! MPG's for that beast are the last things I worry about

[CANUCKPREDATOR]

Trucks aren't made for mileage. I have a hard time seeing anyone with a truck getting over 20 mpg. Not saying its impossible, just very unlikely.

Trucks are heavy and aerodynamics of a barn. If you want mileage get a 4 cylinder car. If you want a truck live with the fact you will never see over 20 mpg

[BJL630]

If you're getting 15 combined now, the best you're gonna see, realistically, is 17-18 combined. If you think about it, that's over 15%, so it's pretty good.

[blairboy3]

I know I wasn't going to get Prius MPG's out of a 4x4 Tahoe, but was hoping to get closer to 20. Is ther anything else I need besides the U7198 tuner? I saw on summit part# U7778. Looks like a power pack & a usb cable to hook up to the computer. Is this necessary?

Thanks for all the help guys, I really appreciate it! Like I said, really have no clue when it comes to the computer tuning!