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.

10 Answers

19,915

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 of 2 people found this 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 of 1 people found this helpful.
19,915

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.

3 of 3 people found this 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 of 1 people found this 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

19,915

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

3 of 3 people found this helpful.
20

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

19,915

no problem.

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

Marvel mystery oil works wonders in fuel gas are diesel it cleans your system out an saves on gas one quart per tank don't matter how many gallons

Your Answer

Add photo

Related Questions

  • 2008 Chevy Silverado 6.6L Duramax fuel problem 10 answers

    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...

    2008 Chevrolet Silverado 2500HD LT1 Crew Cab 4WD

    -

    General

  • Chevy Silverado 2003 2500 Duramax 3 answers

    Ay my chevy Silverado 2003 2500 duramax Suntimes die when I first started in the morning, a half minute after I started it? It won't start again until I hand pump fuel and then it will start Loo...

    2003 Chevrolet Silverado 2500HD 4 Dr LS 4WD Extended Cab LB HD

    -

    General

  • will a 1999 silverado cap from a short bed fit on my 2008 silverado 2500 4 answers

    will a truck cap from a 1999 Silverado fit a 2008 if their both extended cab short beds. Also, mine is a 2500HD series, if the other was a 1500, would that matter

    2008 Chevrolet Silverado 2500HD LTZ Ext. Cab 4WD

    -

    General

  • 2006 duramax diesel 6.6 gas mileage 2 answers

    I am looking to buy a chevy or gmc silverado crew cab with the duramax/allison combo short bed. I would like to know what type of gas mileage I can expect to receive during normal driving and what I c...

    2006 Chevrolet Silverado 2500HD LT2 4dr Crew Cab 4WD SB

    -

    General

  • Towing limit on a 2003 Chevrolet Silverado 2500 HD 6.0 liter 2 answers

    How much weight wait can the stock bumper on a 2003 chevy silverado 2500 HD towe before possibly breaking off.

    2003 Chevrolet Silverado 2500HD

    -

    General

Silverado 2500HD

Looking for a Used Silverado 2500HD in your area?

CarGurus has 28,514 nationwide Silverado 2500HD listings starting at $1,500.

ZIP:

Search Chevrolet Silverado 2500HD Questions

Chevrolet Silverado 2500HD Experts

#1 Steven Loeffler
Steven Loeffler
Reputation 480
#2 piocon
piocon
Reputation 280
#2 Tom Demyan
Tom Demyan
Reputation 280
View All

Related Models For Sale

Used GMC Sierra 2500HD
123 Great Deals out of 12,841 listings starting at $2,995
Used Ford F-250 Super Duty
324 Great Deals out of 44,694 listings starting at $1,450
Used Chevrolet Silverado 1500
1,916 Great Deals out of 183,083 listings starting at $1,495
Used Dodge Ram 2500
125 Great Deals out of 5,076 listings starting at $2,999
Used Chevrolet Silverado 3500HD
101 Great Deals out of 9,956 listings starting at $6,950
Used Ford F-150
2,162 Great Deals out of 195,111 listings starting at $290
Used GMC Sierra 1500
788 Great Deals out of 68,701 listings starting at $1,800
Used Ford F-350 Super Duty
359 Great Deals out of 24,430 listings starting at $2,588
Used GMC Sierra 3500HD
47 Great Deals out of 3,882 listings starting at $10,933
Used Toyota Tundra
458 Great Deals out of 34,712 listings starting at $2,500
Used Chevrolet Silverado Classic 2500HD
22 Great Deals out of 388 listings starting at $4,790

Used Cars For Sale

2017 Chevrolet Silverado 2500HD For Sale
3 Great Deals out of 17,357 listings starting at $28,429
2016 Chevrolet Silverado 2500HD For Sale
16 Great Deals out of 1,752 listings starting at $25,985
2015 Chevrolet Silverado 2500HD For Sale
33 Great Deals out of 1,720 listings starting at $18,900
2014 Chevrolet Silverado 2500HD For Sale
10 Great Deals out of 479 listings starting at $18,095
2013 Chevrolet Silverado 2500HD For Sale
5 Great Deals out of 906 listings starting at $7,200

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.