The Diesel Page Forums

2020 - TDP's 24th Anniversary
What's New | Feature Articles | Product Reviews | Member's Area | Free Forum Registration
Duramax 6600 Diesel Page | Advertiser's Section | Classified Ads | The Diesel Page - Publications

Go Back Forums > 2001 - Current Chevrolet & GMC 2500HD/3500 Light Trucks > Duramax 6600

Duramax 6600 Welcome to the Internet's first Duramax 6600 diesel discussion forum for the LB7, LLY, LBZ, LMM, LML, LGH & L5P RPO code engines. Tips on performance, fuel economy, troubleshooting and more.

View Poll Results: 2004.5 or newer LLY Duramax local driving fuel economy
less than 15 mpg (US gallons) (55-65-mph) 454 41.58%
15-16 mpg 163 14.93%
17-18 mpg 165 15.11%
19-20 or more mpg 220 20.15%
Don't own an LLY - just wanted to see poll data 90 8.24%
Voters: 1092. You may not vote on this poll

Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 06-23-2005, 04:05 PM
G Slaton G Slaton is offline
Join Date: Jun 2005
Location: Bowie,Texas
Posts: 1

I have an 05 CC 2wd Duramax/Allison. This is my fourth Duramax. By far the 03 got the best fuel mileage and ran just about as good as the LLY. I hae driven several LLYs and all run better than mine, local diesel tech says it happens and no real reason why. Running at cruise control 70 It will get a best of 14.7 and a headwind will knock it down below 14. I dragrace and tow a 42ft enclosed gooseneck hauler(14,000#). Normal mileage is 8.9 towing 67 mph.. Headwind will take it below 8.0 I check all fuel mileage by filling to the neck and useing the trip odo. The truck indicator is usually within .1 to .2 mpg of the actual. This truck has 20,000 miles on it and the fuel mileage has not improved with age as I have towed with it from 500 miles on. The LLY has been a bit of a disappointment. I have owned Chevy trucks all my life and am not about to change but this particular truck is not the best one I have ever owned. My LB7 trucks would get 10 towing the same trailer and have been as high as 11.5 on no wind level ground.

Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -7. The time now is 07:08 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Copyright 1996-2020 by - All Rights Reserved