Diesel Truck MPG

whistlebritches wrote:
We averaged 13.5 mpg on a 2 week trip to Tennessee, Georgia, South and North Carolina last summer, pulling a 37' 5th wheel with a 2003 Silverado Duramax/diesel. At home solo, we get 22 mpg. I understand the newer Silverado's only get around 16-17 mpg. And this is diesel.

Is your truck 6.6 V8? Thanks.

Camper 2012 wrote:

laknox wrote:
One thing that occurred to me a few weeks ago as I was filling up my wife's car and calc'ing her mileage. Almost all of us tend to over-fill our tanks; I know I do. Could that .5 to 1.5 gallons of "extra" fuel we pack in be why the dash lies to us when we hand-calc our mileage? I know DW's Genesis is consistently 1.2 to 1.5 mpg less than the dash reports but, as I say, I tend to pack the tank. Another issue that many may forget to take into account is the size of their tires. I'm running 265's instead of 245's on my D'max and I'm 4% under on both miles and speed. If I forget to add those miles when doing an mpg calc, I wonder why my mileage dropped. When I add them back in, I'm up to about where I expect to be.

Lyle

Thanks but I don't need 3500 for my 26' 5th wheel. I am looking for3/4 ton truck.

Just making a comment, Camper2012. I'll refer you back to my previous post, where I said that, from reading here, and other places, towing mpg seems to fall into about 9-12 mpg, no matter the size of your truck. Could be my '02 D'max 3/4 ton or the next guy's twin-screw Peterbuilt towing 20 tons. The single =biggest= factor in mileage is simply how fast you drive...to a point. All trucks seem to have a "sweet spot" where, all things being equal, they seem to just work better and more efficiently. One guy's spot might be 58 mph and the next guy, with the same model truck and a similar trailer, might be 62, or 64, or 66. I know I picked up about 1-1.5 mpg simply by slowing from 65 to 60. I just don't tow enough to get more accurate numbers.

Lyle

Camper 2012 wrote:
The console showed 13.5 and you think this is right.Thanks.

is it 6.7 L. Thanks and have a nice day.

Too Young to Retire wrote:
I have a 2011 Silverado 3500 HD with the Duramax. It gets about 12-13 mpg when towing, and about 16 when not. I don't know if that's "best", but it's good enough for me. And it's for sale with 12,800 miles on it, and still under factory warranty.

Thanks but I don't need 3500 for my 26' 5th wheel. I am looking for 3/4 ton truck

laknox wrote:
One thing that occurred to me a few weeks ago as I was filling up my wife's car and calc'ing her mileage. Almost all of us tend to over-fill our tanks; I know I do. Could that .5 to 1.5 gallons of "extra" fuel we pack in be why the dash lies to us when we hand-calc our mileage? I know DW's Genesis is consistently 1.2 to 1.5 mpg less than the dash reports but, as I say, I tend to pack the tank. Another issue that many may forget to take into account is the size of their tires. I'm running 265's instead of 245's on my D'max and I'm 4% under on both miles and speed. If I forget to add those miles when doing an mpg calc, I wonder why my mileage dropped. When I add them back in, I'm up to about where I expect to be.

Lyle

Thanks but I don't need 3500 for my 26' 5th wheel. I am looking for3/4 ton truck.

One thing that occurred to me a few weeks ago as I was filling up my wife's car and calc'ing her mileage. Almost all of us tend to over-fill our tanks; I know I do. Could that .5 to 1.5 gallons of "extra" fuel we pack in be why the dash lies to us when we hand-calc our mileage? I know DW's Genesis is consistently 1.2 to 1.5 mpg less than the dash reports but, as I say, I tend to pack the tank. Another issue that many may forget to take into account is the size of their tires. I'm running 265's instead of 245's on my D'max and I'm 4% under on both miles and speed. If I forget to add those miles when doing an mpg calc, I wonder why my mileage dropped. When I add them back in, I'm up to about where I expect to be.

Lyle

I have a 2011 Silverado 3500 HD with the Duramax. It gets about 12-13 mpg when towing, and about 16 when not. I don't know if that's "best", but it's good enough for me. And it's for sale with 12,800 miles on it, and still under factory warranty.

The console showed 13.5 and you think this is right.Thanks.

Camper, it's a 2012 GMC Sierra D/A combo crew-cab short-bed 4X4 with 373 gearing. We had an old 2003 GMC, traded for a 2011 Ram Diesel Crew-Cab, long bed with a six-speed manual and 3.42 gearing and only kept it for about nine months, fuel mileage was getting worse rather than better as it got broken in and I came to the conclusion that I didn't like backing, looking over my shoulder, with the manual and having to keep both feet active on the pedals. Just hard for an older, somewhat less than svelte guy like me. The 2012 GMC has been a dream to drive with no problems so far. Just finished another shorter trip to Grand Teton National Park to fish and the console showed 13.7 after we got back home. However, there was quite a bit of none-trailer pulling, we had to stay quite a ways from the lake, about 30 miles, so towed the boat there and back each day. Couldn't tell you about the L, whatever that is, I am not a gear-head, I just buy them and drive them.

jalichty wrote:
Don't know what the best one would be, but my 2012 GMC just did a little over 3,800 miles pulling our Jayco HT 26.5 RLS from Wyoming to Idaho, Nevada, Lake Tahoe, Yosemite, Sequoia, Palm Desert, California, Zion, through Salt Lake and back to Wyoming and got 12.2 MPG hand calculated. Console showed 12.6 so it wasn't that far off.

Can I get more information about your Truck model, L, bed. Thanks.