2009 Duramax Mileage

[corncob]

What kind of mileage numbers are owners getting when you are towing the Montana with a 2008/9 GM Duramax? I am looking at the 09 truck and hearing mileage will be less than the one I have due to the 'new' exhaust. Supposedly, the new exhaust sprays fuel on the particle collector to burn it off, thus reducing mileage. It certainly seems like a moot point to me. Probably an issue for ones that idle much of the time.
Any thoughts?

[exav8tr]

We have an '08 and we get between 9.5 and 11.5, depending on conditions and terrain.

[Jolu]

Our 08 is the same as exav8tr. At times it appears to get better mileage in tow haul mode. I am still evaluating the tow haul mode mileage. I think it all depends on the terrain.

[dmaxmountaineer]

I only towed mine for about 50 miles, but while doing so i got about 10.8 mpgs doing around 65-70. It only uses that extra fuel once per tankfull. The truck isn't constantly regenerating. It all depends how much city driving and idling you do. But on average, it will do it once a tank full. When running empty i get about 21mpg's and with regen, it brings it down to about 10. I would guess that if i'm getting 10 towing, then the regen can't get much worse.

[cmp-shooter]

I was just on a 3 week vacation with my 2009-3500 dually
[ and montana] with
3000 miles + I got 9.2 most of the time and should goto 10 after break in......I get 15 to 17 while NOT TOWING ACCORDING TO DASH READ OUT.

[padredw]

We just returned from an RV trip to California and up through Utah to Colorado and back across New Mexico and much of Texas. Our average for the entire trip, mostly towing but some local driving, 11.15. What I noticed is that wind proved to be the biggest factor affecting mileage. Even over some major passes in Colorado, the mileage evened out, but wind can be a "no win" situation:

[imghttp://dwilliamson.com/TripMiles.jpg[/img] This jpg is too large and causes many folks to have to scroll to read posts. Please use as a link or reduce size to comply with MOC policy.
Thank you,
RVWheels

Neglected to say that our pickup is a 2008 Silverado, Duramax/Allison. I use "Tow/Haul" only in the mountains.

[KathyandDave]

HOW DO i reset the mileage in the dic. I think I'm looking at the average of all miles since the truck woke up in the plant.

[KathyandDave]

Does the regen stink? We notice that sometimes we get a strong diesel exhaust smell.

[exav8tr]

KathyandDave, while the MPG is displayed in the DIC, push the check mark at the bottom. This will start it all over again. When I start on a leg I usually reset it to zero to see how I am doing.

[KathyandDave]

That sounds easy! I'll try it. Thanks.
On edit, it worked! I had to hold it down a couple of seconds.

[corncob]

Have not towed the Monty yet with the 09 Duramax, but drove it over 700 miles bringing it home and averaged 20.5 mpg running at 69 mph by GPS. Around town, at 17 mpg. Thus same as the 06.
Regards

[Delaine and Lindy]

We had a 2008 Chevy LTZ 3500HD DRW's 4x4 with all options and towing our 5er Gross weight was 24,400 lbs we averaged between 9.5 to 11.5 running at 60 mph. Bob-tailing we got 15 to 17 mph running 70 mph. Corncob your mileage sounds awesome. GBY.....

[Bill and Ann]

We went on a trip to Nashville this summer with Potvin who has an 09 2500 GMC Crew. Our truck is the same but it is an 03. When we stopped for diesel we were putting in the same amount so I would say the MPG hasn't changed much.