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Chevy Silverado and GMC Sierra Duramax Fuel Mileage

620 messages,  Last post on Dec 15, 2012 at 3:45 PM

You are in the Chevrolet Silverado & GMC Sierra Forum.

What is this discussion about? Chevrolet Silverado 2500HD, Chevrolet Silverado 3500, GMC Sierra 2500HD, GMC Sierra 3500, Diesel, Fuel Efficiency (MPG), Truck

Messages Page 60 of 63

#588 of 620 Re: 2011 Duramax,CrewCab,2500HD,long bed [hillsdale56] by barrail

May 26, 2011 (2:24 pm)

Replying to: hillsdale56 (May 26, 2011 10:18 am)
hi hillsdale; when you say your gutting the catalitic converter, are you just replacing it with a test pipe and do you have to reprogram the onboard computer?

#589 of 620 Re: 2005 Duramax Fuel Mileage [aarongd] by jerryel

May 30, 2011 (6:23 am)

Replying to: aarongd (Jun 28, 2005 3:53 pm)
I owned a 2001 Silverado, 3500 HD dually with the 8.1/Allison. I owned a very large camper at the time(11 1/2 footer that weighed over 5000 lbs). My mileage when I carried the camper was 8 mpg and around 11 empty(at 75 mph){we lived in Nevada at the time}. When I towed and carried the camper my mileage was around 6 mpg(at 60 mph). The truck was very powerful but the fuel consumption was expensive! I have owned a 2002 Duramax and recently bought a 2011 Duramax and find the diesel is well worth the extra dollars for reliability and much better fuel economy.

#590 of 620 hey barril, whats up? by hillsdale56

May 30, 2011 (2:50 pm)

What I'm going to do isremove the cat, and run with a test pipe. I'm also removing the stock muffler. Installing a magnaflow. 28 inches long, 3.5 inches in and out. When I get it set up and drive for a while, I will let you know how my milage is. I'm going to bring it back to stock. Tune

#591 of 620 my results by hillsdale56

Sep 01, 2011 (11:36 am)

Hello everyone what a storm, upstate ny is a mess. Here are my results. After doing what I said I can get 26 to the gallon with a good grade fuel. I used 3.8 galllons to go 102 miles. City and highway mix use is around 6t00 miles per tank now. Filled to top of neck. Truck does not smoke at idle or while running. I'm happy with it

#592 of 620 MN, but anyone in California in this thread by bulldoggit2

Sep 11, 2011 (9:32 pm)

How do these modifications impact CA emissions tests at registration?

#593 of 620 Re: my results [hillsdale56] by barrail

Sep 12, 2011 (5:19 am)

Replying to: hillsdale56 (Sep 01, 2011 11:36 am)
May I ask, what modifications were made and to what year D-max?

#594 of 620 hello by hillsdale56

Sep 12, 2011 (6:21 am)

What I did was remove the cat and stock muffler. Installed magnaflow number 129909. Pipe is stock size. Truck does. Not smoke at idle or when running. Also have a tuner froom diesel domiination. Ruunniing 25 lbs of boost at 1600 rpm. Look into his tuner. Steve shellly s a good guy and kknnows what he's doing. My truck is a 06. 3.73 4wd hd.. now at 420 hp. To answer the post about california, I not familar wth your emission. Testing. Dooo they put a snffer n the tail pipe, use a mirror to look under the truck? Here n new york we don't have that.no. emiissiion testng on diesels

#595 of 620 06 GMC Sierra Allison by chevyhorsegurl

Oct 03, 2011 (9:07 am)

Looking for some advice here folks...
i drive my truck about an hour each way to work daily, purchased this truck in may of 2011 and was thrilled to see it was getting 18mpg on the drive home! After having the truck a bit i put a soft tonnaue cover on it and immediatly noticed a drop in fuel mileage, to date the truck has been getting around 15.9-16.2 mpg. Wanted to improove mileage so we put cold Air intake system with K&N and did Exhaust with hypertech programmer on stage 2. mileage has not gone up at all since the updates
Any advice would be much appretiated!!!

#596 of 620 Re: 06 GMC Sierra Allison [chevyhorsegurl] by barrail

Oct 03, 2011 (6:28 pm)

Replying to: chevyhorsegurl (Oct 03, 2011 9:07 am)
did you rely on the on board DIC to determine your mileage or did you divide gallons put in to miles driven actual.

#597 of 620 They FIXED my turbo and the fuel mileage dropped by coontie66

Oct 06, 2011 (6:31 am)

Back 1.5 years ago the check engine light came on so I took it to the local Chev garage... Five trips later they eventually installed a new turbo in the 06 Diesel Chev. The fuel mileage never returned to its pre FIX of nearly 21 on the road. Now its about 17-18 on the road.
 
This week the check engine light came on again so its back to the Chev dealer. This time he says its a glow plug and the EGR/ERG pump and a dirty air filter. The truck went out of warranty in July this year based on years NOT mileage... it now has 45300 on it. During the discussion he told me that the new turbo that they put on about a year ago produces more boost than the factory model AND less fuel mileage. Not happy with that. At first the dealer wanted $1050 to fix my problem but when he was told I would trade it in first he decided to extend my warranty a BIT and cover most of the costs. My NEW cost is about $250. What I didn't tell him is my next attempt to buy a diesel PU would be a Dodge. Sure wish they were quiter.
 
I will have to say this 06 Chev is rapidly approaching the top of my list of bad vehicles. So far the Chev Vega of 72 fame and the 80 VW Rabbit are on the top of the list with the 99 Ford diesel in 3rd place. This vehicle is catching up fast and could take 3rd place next year.

Messages Page 60 of 63

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