2008 Chevy Silverado 6.6L Duramax fuel problem

20

Asked by Jan 21, 2014 at 06:49 PM about the 2008 Chevrolet Silverado 2500HD LT1 Crew Cab 4WD

Question type: General

I am only getting 10-12 mpg in my 2008 Chevy Silverado Duramax when other folks
claim their getting 16-17+.  What could be wrong? I had a certified tech put the monitor
on it and it checked out with no red flags or bad codes.

9 Answers

18,135

Do you have the factory size tires on it? Add a quart of transmission fluid to the fuel tank to clean the injectors. Air filter new?

2 out of 2 people think this is helpful.
20

My driver door says it should have 16 inch tires, but it has 265/17's on it and I'm pretty sure it came with the 17's on it. It's funny you mentioned the air filter. I had the tech check the truck out last night, and through conversation, we pulled the air filter out and it was grey and you couldn't hardly see light through it. I bought a brand new one today, but haven't had enough time to see if it helped.

1 out of 1 people think this is helpful.
18,135

That is a big part of it. You can also buy a chip for it and set it in safe tow mode and it will increase the mileage and power. Usually 3-7mpg gain. I run superchip in mine.

2 out of 2 people think this is helpful.
20

Also, are you referring to Dexron III transmission fluid? I have heard of adding transmission fluid to the fuel tank, but wasn't sure it would hurt the engine

1 out of 1 people think this is helpful.
20

I pull a 33ft fifth wheel camper with my truck or I will be. I just purchased the truck and figured I would be getting a lot better gas mileage. I have not pulled the camper yet to see what mileage I get with it behind the truck. I sure hope the air filter helps

18,135

Yes that is fine. One quart to a full tank of fuel is good for it occasionally.

3 out of 3 people think this is helpful.
20

Ok.....I'll try it and see if it helps. I appreciate your help!!

18,135

no problem.

tans fluid in the fuel tank is not recommended. Have replace many injectors on duramax's for people using "old school" tricks.

Your Answer

Add photo

Related Questions

Silverado 2500HD

Looking for a Used Silverado 2500HD in your area?

CarGurus has 27,211 nationwide Silverado 2500HD listings starting at $2,998.

ZIP:

Search Chevrolet Silverado 2500HD Questions

UK Questions

Are you a UK consumer? CarGurus now has a discussion forum in the UK.

Chevrolet Silverado 2500HD Experts

#1 Steven Loeffler
Steven Loeffler
Reputation 420
#2 FordNut
FordNut
Reputation 280
#3 Tom Demyan
Tom Demyan
Reputation 260
View All

Related Models For Sale

Used GMC Sierra 2500HD
156 Great Deals out of 13,277 listings starting at $3,500
Used Ford F-250 Super Duty
468 Great Deals out of 43,492 listings starting at $1,900
Used Chevrolet Silverado 1500
2,588 Great Deals out of 152,648 listings starting at $1,500
Used Dodge Ram 2500
162 Great Deals out of 5,650 listings starting at $2,995
Used Chevrolet Silverado 3500HD
99 Great Deals out of 7,732 listings starting at $6,995
Used GMC Sierra 1500
991 Great Deals out of 60,344 listings starting at $1,299
Used Ford F-150
3,112 Great Deals out of 209,132 listings starting at $1,200
Used Ford F-350 Super Duty
416 Great Deals out of 26,396 listings starting at $3,495
Used Chevrolet Silverado Classic 2500HD
24 Great Deals out of 378 listings starting at $4,790
Used Toyota Tundra
666 Great Deals out of 28,480 listings starting at $2,798
Used GMC Sierra 3500HD
70 Great Deals out of 3,535 listings starting at $9,995

Used Cars For Sale

2017 Chevrolet Silverado 2500HD For Sale
8,898 listings starting at $25,725
2016 Chevrolet Silverado 2500HD For Sale
17 Great Deals out of 7,663 listings starting at $23,384
2015 Chevrolet Silverado 2500HD For Sale
81 Great Deals out of 2,022 listings starting at $19,988
2014 Chevrolet Silverado 2500HD For Sale
21 Great Deals out of 608 listings starting at $15,995
2013 Chevrolet Silverado 2500HD For Sale
10 Great Deals out of 1,052 listings starting at $9,995