Fuel mileage of a dually vs. single

[JSteward]

I'm in the market for a new truck and am concerned with fuel economy. I'd like to have a dually like I do now. I like the look and the feel whenever I'm pulling my RV. But I'm concerned about fuel economy. I'm sure it makes some difference considering the extra surface area w/ contact on the road and additional weight.

Anyone know how much difference we're talking?

Thanks,
Jason

[cowboywildbill]

On a Duramax C/C If your towing big and heavy, then you won't notice much difference in mpg while towing with a dually vs a single. But the added stability in my mind is well worth the 1/2 to 1 mpg difference. If you drive empty not towing a lot, you will see somewhere in the 2 to 5.5 less mpg with the dually. These are guesstaments. It depends on how and where you drive. Speed is a big factor. Hope that helps. There are some forums about milage on this page. Check them out they may shed a lot more light on the subject. Good luck in whatever you drive.

[JSteward]

I drive as economicly as possible. I will very seldom drive w/ a trailer. Probably only a couple times per year. I'll be driving on a variety of grades... but mostly flat.

Thanks. 5 MPG difference would make a big enough difference for me to forgo the dually.

On a similar note, if I wasn't going to get a dually, I could see no reason to get a 3500.... that is, if the 2500HD gets better fuel mileage.

Thanks,
Jason

[JSteward]

I didn't see a "fuel economy" forum. Should this be posted in the "performance" forum instead of this one?

[cowboywildbill]

I think this page is probably OK for the fuel mpg post.
I notice that the moderators have moved some of the post if they fit into another area better.
Back to the 2500 and 3500 trucks. I don't know this for a fact, but I would think that the 3500 single rear wheel models would get about the same mpg as the 2500 trucks in the same cab and bed styles. Just a thought if you do ever need the extra beef to tow heavy and don't want to go the 3500 dually route, then maybe the 3500 single rear wheel will work for you.

[Craig M]

With the same engine, transmission and rear end ratio, you will see little difference in fuel mileage with a 2500 or 3500 single rear wheels. Since you were considering a dually, the 3500 single rear wheel would probably be a better choice. I also think the prior post on mileage "loss" for a dually were overly pesimistic. Get some more data before you make your decision.

[Mark Rinker]

What kind of weight is your truck carrying when towing? It really comes down the the scale ticket - the weight on your rear axle should not exceed the combined DOT weight rating of the tires under the load.

Sounds like a SRW 3500 would be the ticket for you, yielding better mileage year around, and good weight carrying capabilty while towing.

[cowboywildbill]

I was just guessing on the milage loss for a dually going by what our friends average and my own experiences. I just averaged 15.7 mpg driving 108 miles at semi hwy speeds of 55 to 65 and a few traffic lights and rolling hills.
Our truck only has 1100 miles on it and we were empty. On a simular trip a friend of ours in a 2500 short bed version averaged abour 18 mpg on almost the same trip.He only had 37 miles on it, just picked it up at the dealer. He did his when the weather was warmer. We did ours at 35 to 40 f. That may have had some bearing on it. Most people I talk to tell me that empty they lose about 3 or 4 mpg with a dually when empty compared to a non-dually. I don't think there is much difference in the two if you are towing heavy.
I agree with the other post that maybe a 3500 SRW would be the way to go.
Good luck and let us know what you end up with.

[mshicks]

i had an 'o1 duramax 2500 extcab shortbed and now i have an '05 duramax crew dooly. the dooly gets 21.5 mpg at 60 miles per hour and 17.5 at 75 miles per hour. i love the dooly for the extra stability and with roughly the same mpg as the '01 on a bigger chasis rocks.

[cowboywildbill]

WOW that is great mpg. I never got more than 18 mpg at 55 mph on our 02. I averaged around 15.9 mpg. And towing any where from 10.5 to 13.5 mpg.
I sure hope after our 07 dually gets past the break in period, that it will get the kind of milage you are getting now.

[MartyB]

Older versions will get 15-18 empty, ie duallies, but my 05 gets 13-14.5 for the most part around town, I think I have hit 17-18 maybe 4 times in the last 18 months and 36K miles. But those 4 times, are the ONLY times I can say I was ALL freeway miles at 60'ish or so with cruise on. Most of the time it is city driving. I am ave less than 30mph based on miles and hrs.

Singles will get 2-3 mpg more empty than a dually. My old 96 SW K3500 6.5 got better mileage than currrent rig, at times other than power, I wish I still had her, but not shifting a manual, is nice!

[STPETEBLUE]

I'm about the same as MartyB, except I do a little better highway. If I drive 55mph :eek: I can get around 20-21 mpg. At 75mph I get around 17mpg.

[Albee]

I had an 02 LB7 2500, I would get 15-16 running around town. I now have an 06 3500 Dooley with the LLY. I see about 12.5-13 around town. It did drop. These are and were both crew cab long beds. Good luck.