Fuel Mileage difference between SRW & DRW??

[Gobbler]

Thinking of upgrading this year and am researching. Can't get the "search" feature to work for me this morning so I apologize if this has been asked before. Generally speaking, how much difference can one expect in fuel mileage between a 3500 single rear wheel and 3500 dual rear wheel?

[rob from bc canada]

Can't help you with the difference exactly, but I've been following this and another forum extensively, and have not seen a big difference come up in any of the many fuel mileage topics.

The biggest differences always come down to driving style, speed, wind resistance, hills, and load weight, but all else being equal, there has to be some difference for the Dually.

However, if you don't need the extra width for stability of a huge camper or something, or the few extra pound of legal load capacity, I'd go with SRW every time no regrets,

- Easier to drive and park (unless you never go to town)
- Tire wear is much faster on DRW, and you have to replace more tires
- I think they look ugly - that's a matter of opinion!!

[Gobbler]

Thanks, Rob. Anyone else?

[cowboywildbill]

I am convinced that if you have two trucks in exactly the same configuration, example crew cab long bed D/Max allison 6 speed. One is single rear wheel and one is dual rear wheel and driving them the in the same manor, the dually will get any where from 1 to 3 miles per gallon less when running empty. The faster you drive above say 60 mph in the dually the milage will fall off more than the single rear wheel will. But if your towing 9,000 lbs or more, both trucks will get pretty close to the same mpg. I don't have any data to back that up, but we run together with different trucks going to rodeos and pennings and this seems to be the case. If you don't need the duals and your running empty a lot and not towing heavy, then the single rw might be the ticket. It is easier to park and get past bank drive thru's.And rides a little better empty. But if you tow moderate to heavy loads, the dually is safer and more stable. Hope that helps.

[Mark Rinker]

I concur with most stated here, but will add my conclusion after owning, towing and plowing with a few late model K2500 and K3500 trucks.

"The only compelling reason to own a dually is to carry the pin weight of a gooseneck or 5th wheel trailer."

We have towed 6K-8K average loads day in day out, snow, rain, sleet, etc. with a bumper pull 30' trailer literally hundreds of thousands of miles behind SRW trucks and have saved plenty on fuel. I have never felt unstable braking or laterally - even when towing boats that outweighed the truck by 50% off the bumper. Any of my operators will pick the SRW over the DRW any day for plowing snow as well. No advantage for traction.

We just upgraded our 'in town' rig from a '02 K2500 (SRW) pulling a the 30' bumper trailer, back to a 30' gooseneck behind the 2006 dually, and are averaging a solid 2mpg average less MPG, and picked up only an additional 3K (legal) load carrying capacity. Most of that loss is in the additional weight of the truck and the trailer. The phrase "Diminishing point of return" comes to mind.

We have not tested the '06 with the bumper pull trailer, but may in the near future to do a fair comparison of that mileage compared to the '02 K2500 which has yielded great mileage for us.

If you can get by with the SRW, and intend to use the truck as a daily driver more than a tow vehicle, save the fuel, save the tires, and have a more trade-friendly truck at the end of your ownership. SRW 3500s are a rare bird and bring a good price down the road. The guys that like them will pay a premium for them used and clean. Duallys are easy to find, and always suspect of just how hard they were towed.

My $2.02 cents worth. :)

[mark45678]

the duramax motor is more sensitve to RPM while driving more then weight. I tow at 70~72 mph with my holiday rambler , If its reasonable flat it will get over 11 mpg. The same truck no trailer in tow gets 15~16 mpg , if I drive faster like 80 mph it gets 14 mpg.

I think a 4x4 truck may hurt mileage comparted to a 2 wheel drive but its only going to be 1/2 ~3/4 mpg in my opinion.