single wheel VS Dually drives

[OntarioVanMan]

I don't know what the official name for them is but I was with a guy in orientation, tractor driver and he had on that new configuration of two drive tires instead of four....extra wide tires. Looks cool, he said it saves him about 1 mpg which translates into almost 9,000 bucks a year in fuel savings. He said it costs about 5,000$ to change the axles over but well worth it.

I woulda thought the ATeam would have checked this out. Better yet
night creature a TT owner.

 

[ATeam]

They are called super-singles or wide-base single tires. We did check them out and decided to go with traditional duals.

Super-singles are most often seen on trucks where the weight savings of the super-single setup can translate directly into additional freight on board; such as tankers where a few hundred pounds off the wheels can mean a few hundred pounds more freight pumped into the tank. I believe Wal-Mart is also converting its fleet to super-singles over time.

The decreased surface area of super-singles and stiffer sidewalls mean reduced rolling resistance and thus improved fuel economy. On an 18-wheeler, a super-single conversion would change 16 wheels into 8. On a 10-wheel straight truck, it would be 8 wheels into 4. Thus, the super-single benefits are less on a straight truck, which brings the cost of the conversion into question.

When we spec'ed our truck, meaningful data about the fuel-economy savings that super-singles may bring to a straight truck was not available. As far as I know, is still isn't. While we could have spec'ed super-singles on the brand new truck, and thereby saved the cost of conversion later on, we chose not to. Super-singles were still finding their way to market acceptance at that time. In the event of a needed tire repair out on the road, service for traditional dual tires would be easier to find. Super-singles are more available out there now, but not in all markets, like remote Montana and rural New Mexico, where we sometimes find ourselves.

The slightly-wider stance super-singles provide may provide a stability advantage in some straight trucks. But body roll is not an issue with our current truck, so that is not a reason to convert.

Someday, after the truck is paid for, and just for the heck of it, I might convert to super singles. I remain curious about the difference super-singles may make on a straight truck. They also look very cool (personal opinion of course). It would be interesting to run super-singles on our truck for a year and compare the drivability and fuel economy results to the year-before when we were running duals on the same truck.

However, based on the information now available, I do not believe the fuel economy savings would be enough to justify the cost of buying the new wheels that super-single tires require.

 

[RichM]

I believe it is illegal for single axle trucks to have the super singles installed ,as if one was to blow out on you, the truck would not have the other tire to keep it upright. On dual axle tractors and trailers it's legal.

 

[LDB]

When building my Kenworth I looked into them. At that time the Bridgestone people said they estimated a savings of about 2/3 mpg for my application and felt certain it would fall in the .5-.75 window. I went with traditional duals for the same reasons already mentioned. If/when I do another one I will probably go with them.

Leo Bricker, 73's K5LDB, OOIDA Life Member 677319
Owner, Panther trucks 5508, 5509, 5641
Highway Watch Participant, Truckerbuddy
EO Forum Moderator
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[greg334]

Rich,
I know that the DOT and EPA is planning on promoting the tires soon on all trucks, targeting tractors but includes single axle trucks. They are slow with all their programs so I would expect to see something when we have converted to Hydrogen in 2027.

The reasoning not to use them seems to be a little more 'don't want to change a good thing' than it really has to do with safety and mileage.

The fact that these tires are used over in Europe for a few years before hitting our shores at least insures that they are accepted as safe and reliable.

I know you agree that the tire is only as good as the care it gets, tire pressure, regular cleaning and inspection and proper axle alignment. Many tires fail if they do not receive the proper care.

 

[OntarioVanMan]

I talked with a couple drivers this morning about these super singles and the foremost reason that came up was: In the event of a flat or blowout your done with. Stop where ya pop as they said, at least with a dually if it's an inside tire you can still drive to a service place and depending on the load even with an outside gone down. You would quickly lose the any savings in one service call and missed time.

 

[greg334]

I think being fully loaded and have an inside drive tire go and then driving on it is more dangerous than having a single tire blow out. The other thing is we don't have dual steers, do we?

 

[layoutshooter]

I would be concerned with performance on snow. I was raised with the idea that narrow tires work better on snow than wider tires. My snow tires were always 1 or 2 sizes narrower than my summer tires. On my 4-wheel drive we used narrow snow tires and wider tires on mud so we could "float" on it. I would love to see studies on the wider tires. Do they perform well on snow? Do they hydroplane more? I like the idea of the weight and fuel savings. I would love to see some real testing on these things. Layoutshooter