mine with all the mods that it has gives me 12mg on the highway empty but put a trailer with my brothers 99 chevy on top and it goes down to about 7-9mpg on the highway but yet i also drive it like it is not my truck

 

My 02 6.0 2500HD has a K&N intake system, Granatelli MAF sensor, ? TB, shortie headers, stock cats , true duals Magnaflow mufflers dumpped, Hypertech PP (pos) and I'm doing 24-27 MPG. It has Nitto Terra Grabblers and 20x10 USA Forge Wheels. It does the same as my 2000 Z-28 except, the car does a modest 440hp at the fly.

 

How do you guys like the LTs on these trucks? I've been thinking of swapping them out. It came with Edelbrock shorties so they do the trick of improving gas milage but what do the LTs provide as far as power? Let me know. I was thinking of getting them from Texas Speed. Anybody? Pinche raza...

 

I thought that going with a CAI and exhaust would help out on our Yukon like it did with our previous Durango we had, but when it came down to it, the 4.10 gearing makes the motor spin so fast on the highway there isn't much you can do.

The best we've seen is 16 on the highway. We only saw 13 mpg on the highway recently with the wind in our face going down I-40.

 

Here's the solution, trade the 2500 in and get a 1500 HD. It has 3.73's in it and even with the lift and tires I'm running, I still see 16 or 17 on the highway (when my girlfriend is with me) When she's not with me, I like to pick on imports and my mileage goes straight to ****, but there's no reason a mature adult like yourself couldn't get at least 16 mpg with my setup.


Oh, by the way, it tows without looking back.

 

our is stock, crew cab 4x4 4:10.. about 12 mpg is the best it gets unloaded.

The 4:10 vs 3:73 is only about 5-700 rpms depending on if each tach is the same. The truck at 80mpg truns 3000rpms with 245-75-16 tires, the suburban 8.1L turns 2450-2500 ( the tach seems to float) at 80 mpg with 245-75-16's... that assuming the speedo's are correct on each one.

One thing you might look into is a gear vendors over drive kit. It will over drive the over drive... probably drop you 1,000 rpms or so on the free way. I have one in the supra behind a th400. works like champ.

As for the chip / tune they usually get the better milage buy leaning out the motor... not something that sounds safe if your pulling. Id say bite the bullet and pay the gas bill. If it makes you feel better this is our 6.0 towing.

 

[QUOTE=Kerr;3907872]If it makes you feel better this is our 6.0 towing.
/QUOTE]

That is your instant MPG. What is your average MPG while towing?

 

Yea that climbing hills.. Depends on the load. the supra and trailer. about 10 mpg. the trailer adn the suburban ( that is when that picture was taken) was 8.5 mpg but thats a lot of weight. I figure a 2500 burban is 7K, and the trailer is 3K.

Also i go with traffic. Im not the guy going 45-50 mph on the freeway. that instant mpg picture was at 75. mph. It seem ( no proof behind this ) that if you stay between 75-80 mph with a lot the mileage is better than when going 65. Im not sure if that puts the motor in the sweet spot on the rpms or if the weight overtake the rolling resistance...

 

I have observed the same thing with one of my previous trucks. It had 4.10's and at 80 it would get slightly better mileage than at 60-65. The truck I have now has 3.73's and speed doesn't change the fuel economy.

 

I have 35's on my RCLB '01 2500HD with the LQ4, and I usually get around 11-12mpg in the city, but that's also pretty hard driving. When I'm on the highway, I can get about 15mpg when I stay around 60-65mph, but anything above that ends up 12-13mpg.

I did manage to get 21mpg one time, but that was with a 70+mph tailwind from a really nasty storm shoving me down the freeway . Sadly I only got single digits when I drove back into the wind, so the whole trip came out a wash .

Tom