DuraMax mileage

[Steven_and_Ann]

I am the new owner of a 2008 DuraMax crewcab with 52,000 miles on it. I am getting 13 miles per gallon in town and 17 on the highway with no 5th wheel hooked up. I expected a couple of miles per gallon better than this but have little diesel experience so dont know. The air filter was dirty and I am thinking of replacing it with a K&N. Is this mileage typical and does anyone know what I can expect pulling a 3250 (which we will pick up next week). Other that slow starts and gentle stops is there anything that will improve my mileage? Thanks in advance for your response. Steven

 

[Bob&Patty]

Steven, I have an 07 Classic C/C L/B 4WD. I get about 13-14 around town and 17-19 on the road. Pulling I get 11-12. I would say that your truck is about normal. The big 3 all get about the same. As far as the K-N filter system...save your money. They have a terrible dirt stopping record. My best advise is to leave your truck the way it came from GM. All the hype about better mileage from tuner's is a bunch of crap (now the arguing starts). All tuner's do is dump more fuel for more power. So do the math...if you dump more fuel your mileage will go down. You also can damage the engine because of too much combustion pressure and heat. I say all this as a retired GM for 47 years. So, start the fight, I bet I know more about the Duramax than most. I have seen what these tuner's do to engines and it's not pretty. A new Duramax engine is about 13K. BTW, the Duramax's computor will up the HP by 100HP by itself when in Tow/haul depending on the throttle angle. SO LEAVE IT ALONE and enjoy...it will pull anything you want.

 

[SJH]

I agree with the K & N filter statement...I have read nothing but negative things about them on the Duramax Forums! As far as mileage...average about 10 - 11 towing the 3450TS over the North Cascades. Town mileages are the same as Bob&Patty above only I don't think I have ever gotten 19 on the highway...more like 16 - 18.

The Duramax will tow your 3250 just fine! The Big Country's tow really nice.

Congratulations on your new rig!

Best Wishes!

 

[JohnDar]

The mileage on my 2009 is right in line with what Bob posted. Don't forget, driving around town is stop and go. Every time you take off from a stop, you're sucking fuel until you get to a steady speed. Idling at a stop, you're burning fuel but not getting mileage out of it.

And unless you reset you mileage display for each driving situation, you're getting a composite average from the last reset. The only "upgrade" I made to my truck was to replace the 34 gallon fuel tank with a 56 gallon one.

 

[branson4020]

Same mileage - 10-11 mpg towing with my 6.7L Cummins. Only way to improve it, is to park it.

 

[caissiel]

I would recommend a ScangaugeII and learn to drive the truck with a load. Best investment done for my truck. I have been using the Max Energy programer for 4 years with very good success, but only by observing the driving habits with the ScangaugeII. I would never pull the trailer without the ScangaugeII.

 

[TedS]

My 2004 crewcab, 4x4, long box has 100k miles and the computer average for all those miles, including towing, city-go-to-work, highway, shows 15.6 mpg for overall driving.

 

[Bob&Patty]

Bob (branson) your a funny little guy. "park it" LOL. Steve, you bought a vehicle made to pull weight. If you don't try to burn the tires down to the lug nuts from a stop, you will be fine. At a steady speed in 6th gear traveling you will be surprised what you get. Use the tow/haul...drive in the "M" position and select your gears. I love that feature...works good for downhills. The only thing that you might add is a Jake brake or the Banks exhaust brake. The only thing that I want add is a turbo boost guage and EGT (pyrometer), anything over 1300* and you start to melt pistons. They are on my bucket list and Patty's crap list.

 

[rustyshakelford]

i have a 2010 lmm and on my way home from elkhart with our 3010 full of water/fuel and rhino we got around 10.5-11. I only have 12k miles on it know. when we got into NW arkansas, we dropped down to 8.7, but that was with some 20 degree grades and not going much over 45 up and down the hills.

With bob's statment about gaining 100 hp with t/h...Thats the first i have heard about that. I was in the diesel performance world with my old cummins and was pretty knowledable about the common rail 5.9s. The duramax is new to me but I have yet to see any dyno report that shows such a large increase with using t/h. Not saying its not true, just I havent ever heard that. My understanding is that is adjust the shift points top reduce downshifts and enables transmission braking when slowing.

The only upgrades i will be doing will be some sort of aftermarket exhaust brake (fleece more than likely) and maybe a small tow tune. I am leary about voiding my warranty on this truck!

brett

 

[gmc]

I to get around 13 to 14 around town upwards of 17 0n the road and about 10 to 12 towing my 3055 bh (06 sierra duramax)

 

[Nabo]

We must be the oddballs - our 09 Dodge 3500, single rear wheel with 373 axle gets 17-18 mpg driving back and forth to work. Byrd drive it daily going about 25 miles each way over a mountain ridge. Pulling the BC we average about 12mpg.

 

[ATLJOHN]

I get about 17-19 hwy w/o towing. Towing I set my speed control at 62-63 and get 10-11.5 on average. I love my 2006 Duramax. I think if your change your air filter with OEM filter that will improve your mileage for sure. Good luck with your new BC. They are great rigs.

 

[tmcran]

Don't waste your $$ on K&N. They foul the MAF sensors and gum up with dirt. Stay with OEM filter. Can order online.07 LBZ city 13-14. Highway 17-20. Drive about 65-70. RPM below 2000. Towing 10-12. 65 mph max. When towing use T/H and leave it there. JMO.

 

[Duramax1]

I use T/H mode whenever I am towing. I did not know that this was providing me with an extra 100HP. Wow!

 

[hillsonwheels]

Have an '08 Silverado 2500 short box with 4WD. Bought it new and picked up Bighorn 3400 RL right away. Have never gotten much better than 16 mpg empty and have ranged from 8.8 mpg (while new) to around 10 mpg (now have 48k on truck) when towing. Always use tow haul and run 65 mph when I can @ 1750 rpms. That is all hand calculated...not from the dashboard wizard. Had hoped, when I bought, that I'd get 12 mpg or better but I don't believe it's in the cards.

I did add a 50 gal aux to reduce worries about where's the next fuel and a Banks braking system to take the worry about serious down grades out of the equation. Have saved a lot of seat cover material from puckering since that was installed.

Nevertheless, we will keep doing the camping "thang" as long as we can. There are many rallies out there that need attendees!

 

[GOTTOYS]

Finally! People are recognizing that that this K&N, and Cold Air Intake hype is just what it is. Highly profitable JUNK for all it's manufacturers that makes lots of claims of "up to" so many H.P. gains but produces nothing...If it was all that easy it would come from the factory that way...Don

 

[Bob&Patty]

Don, thats what I like about you......straight to the point. No wishy-washy from you. It is what it is. It is really crazy how people get there blummers in a twist when you tell in like it is. ROTFLOL

 

[caissiel]

I had 2 GM Diesels that I had to change the air filter at every oilchange. I used K & N filters for 13 years with absolutly no problem and got great increase of power with the naturaly aspired 6.2L.
The Ford has the best air filter so I did not bother using one in mine so far.

 

[Bob&Patty]

Laurent, 6.2's didnt have a MAP or a MAF sensor either.

 

[tmcran]

I had 2 GM Diesels that I had to change the air filter at every oilchange. I used K & N filters for 13 years with absolutly no problem and got great increase of power with the naturaly aspired 6.2L.
The Ford has the best air filter so I did not bother using one in mine so far.

Wow where do u live ? Air filter every oil change...Did u have big blue round one? I drive a ton on dirt roads have changed air filter 3 times with 70,000.