New Guy 2002 Gmc 2500 Hd With A 8.1l

[REV353]

2002 GMC 2500 HD need 8.1L helpDo's and Don'tsI bought the truck 10 months ago, needed it to pull my 24' trailer. I went with gas for over all cost. I changed the motor and drive train over to Amsoil the week I got it, and that was it until last week. I got 8 mpg on the hwy, I put 2 tank fulls of Lucas injector cleaner and got 8.6 on the last tank. From what I have read I should be getting 11-14 on the hwy, 10 would be nice. When I got home I took out a spark plug and it was on it's last leg, I installed Autolite iridums and Taylor 25 ohm wires and a Helix type throttle body spacer. Boy could I notice the diff, I also have a cheap ebay cold air intake coming to replace the Amsoil hiflow airfilter. Not sure what else to do, I know a HyperTech programer will not help, I lost mpg on my last truck using one, gained a heck of alot more power though. Not sure if I should of bought a Cummings. Didn't mean to swear.

[Porter_]

don't have answers to your questions but just wanted to say welcome to the forum . there's some knowledgeable people here so i'm sure someone will chime in and answer your questions. nice toys you have there.

[Dirtbikindad393]

Welcome to the forums also.

 

As far as mpg goes thats a hard call there are so many factors. You might have 4:11 gears in the rear and that won't help much at all. Cruise control when ever possible. An Exhaust system would help. I run a PPE and it helped my mpg in my Duramax. Not sure if they make it for the gas engine but I would think they do and I would think it would help.

[REV353]

Welcome to the forums also.

 

As far as mpg goes thats a hard call there are so many factors. You might have 4:11 gears in the rear and that won't help much at all. Cruise control when ever possible. An Exhaust system would help. I run a PPE and it helped my mpg in my Duramax. Not sure if they make it for the gas engine but I would think they do and I would think it would help.

 

 

I checked into the gears, it's a GT4 code, should make it 3:73

[ALange]

Welcome to the forums also.

 

As far as mpg goes thats a hard call there are so many factors. You might have 4:11 gears in the rear and that won't help much at all. Cruise control when ever possible. An Exhaust system would help. I run a PPE and it helped my mpg in my Duramax. Not sure if they make it for the gas engine but I would think they do and I would think it would help.

 

 

I checked into the gears, it's a GT4 code, should make it 3:73

 

 

 

I had an 02 8.1 4x4 Alison with 4.10s in it. I think I got around 12 MPG give or take. It was bone stock and I was not trying to get good mileage.

[REV353]

Welcome to the forums also.

 

As far as mpg goes thats a hard call there are so many factors. You might have 4:11 gears in the rear and that won't help much at all. Cruise control when ever possible. An Exhaust system would help. I run a PPE and it helped my mpg in my Duramax. Not sure if they make it for the gas engine but I would think they do and I would think it would help.

 

 

I checked into the gears, it's a GT4 code, should make it 3:73

 

 

 

I had an 02 8.1 4x4 Alison with 4.10s in it. I think I got around 12 MPG give or take. It was bone stock and I was not trying to get good mileage.

 

 

This is what I keep hearing, 11-14. I just filled up lastnight, 8 mpg

[DofD]

Hi there and welcome to GM Trucks!

[BuckFeverZ]

Welcome to site

 

The mileage you are posting, is that while towing your trailer or unloaded?