Break in for 6.0L

[Colossus]

Correct, 2001 introduced the GMT-800s for the 2500 & 3500 series. Prior to that they were the old box style 90s look. 99 introduced the 1500 GMT-800.

[revrnd]

Correct, 2001 introduced the GMT-800s for the 2500 & 3500 series. Prior to that they were the old box style 90s look. 99 introduced the 1500 GMT-800.

GMT400s

[Colossus]

Why can't they just go in sequence? <sigh>

[revrnd]

Why can't they just go in sequence? <sigh>

Who knows? 400, 800 900 then K2XX. When we started building the CC short short boxes that program was the GMT943 (43 has been GM's code for CC for years.

 

https://en.wikipedia.org/wiki/GM_GMT_platform

[RJP44]

You can't base the MPG off a truck with 55 miles on it!! Im sure its only been on test drives and i have a feeling not everyone babied it on the test drive. The milage will go up the more you drive it. Yes the MPG suck on the 6.0 but its a proven design and plenty of power imo.

[revrnd]

You can't base the MPG off a truck with 55 miles on it!! Im sure its only been on test drives and i have a feeling not everyone babied it on the test drive. The milage will go up the more you drive it. Yes the MPG suck on the 6.0 but its a proven design and plenty of power imo.

I've had 3 and picking up #4 next week. I've never bothered checking the mileage as it is what it is. I had an '88 S15 & went back to a full size in '94. For me the hauling/towing capability was more important than mileage.

[Rob2500hd]

FWIW my 2016 6.0L has 700 miles on it and I filled up today at 13.5mpg, hand calculated. Was expecting worse.

[RNGRBOB]

I just broke 1500 miles on my 2016 2500HD, and I'm sitting at 14.3 for the last 400 miles from a drive from Fayetteville NC to Knoxville TN with a mountain pass in-between. Thats traveling about 70-75 and no weight in the back or hauling anything. Not too shabby for that truck....

 

FWIW my 2016 6.0L has 700 miles on it and I filled up today at 13.5mpg, hand calculated. Was expecting worse.