Just curious, anybody know what the advantages/benefits are for using super single tires on big rigs as opposed to standard dual tires? I'm seeing a lot more trucks using singles nowdays, short haul and long haul trucks.
From what I am told weight savings of 70LB per wheel with singles and better fuel milage.
I have heard the same and something was said the rolling resistance is better also. My oldest boy drives for TMC and is running super singles
My grandparents run 255's on thier trucks, we weighed them and found that a set of two 255's on aluminum wheels are 50 lbs lighter than one super single on an aluminum rim.
If I remember correctly one super single is cheaper than two trailer tires if you are running virgin rubber. I guess they are supposed to save fuel too. That being said they are a pain to change and if you're running long haul you might have trouble finding one. Also once you have one go down you're dead on the spot. Road calls can get really pricey when someone has to come from 100 miles away to change one.
Can someone explain this a little more? I've never heard of them. One bigger tire carries the same weight as two? I guess if the tire must have (almost) twice the patch on the ground, to spread the same amount of weight?
I seem to remember hearing that a Super Single will run cooler than duals. Most of the internal tire friction (thus heat buildup) is from the sidewall/tread junction, and so a SS would have half the friction as a set of duals. This is where a lot of the fuel savings come from. Another benefit is that you can't miss a low tire. I am sure you all know how "hard" it is to check tire pressure on duals, which results in people just thumping the tires instead of actually checking pressure. Even just a few pounds off, or a few pounds difference between duals will create a lot of extra drag, heat and wear. You don't get as much scrub as with duals when turning sharp, and you don't have different tread heights from mismatched tires or different wear rates. Then you get the downsides like not being able to limp home with 1 flat tire, often a narrower wheelbase by a couple of inches, the rim often being destroyed in a blowout, the cost, lower availability of the tires, etc. @Stevenbrla: Basically! Look at the Flotation tires often used on the front of dumptrucks and cement mixers. They are very similar. The ones I have on the front of my 10 wheeler are rated at 10K+ each. Around here they have been using them on wine and fuel trailers for a long time, and now some are starting to use them on drive axles as well. Ben~
With hazmat loads you don't have to get out and inspect the inside duel every 100 miles if you have singles. (i think)
You also get a tire that runs true instead of the wobble of poorly matched or mounted duals. The reduced friction and fuel savings are becoming more critical as the price of fuel drives ever higher. I would wonder about the safety of losing one on a downhill curve.
Unknown to me, but I have to think there has to be some research info out there that shows a benefit/advantage to using super single as opposed to duals because I'm seeing more and more trucks using them, and I don't think "corporations" are fitting these tires on their fleets simply to be a part of a fad. There has to be some logic to it. As for blowouts, again, unknown to me, but I speculate there may be an advantage by virtue of it being a single tire. I mean, in order for a single to carry the same load as duals paired up, wouldn't the single have to have a radically thicker build as compared to a typical tire used for duals? In a radical sense, kinda like a "wheel loader" tire on a rig, making the super single a beefy, thick build tire. With that being the case, does that somehow make them a tougher tire that is more resistant to the circumstances that cause a blowout on a rig traveling down the highway?
Thanks for the explanation, Ben. A SS must be radically wider than a normal tire, for DOT to accept that much weight to be transferred to the road... isn't that the reason for mulitple axles(tires)....?
The tire isnt any thicker, the rubber is not what is holding the weight, the air pressure inside is. They are almost as wide as a set of duals and are supposed to save fuel by having less rolling resistance. If weight savings are your goal super singles are not the lightest setup, dual 255's are still lighter.
they look to me like they would hydroplane easily in the rain
I haven't found much difinitive info on the web yet, but I've found that one reason for the fuel savings is the reduced friction of running singles as opposed to dual tires. It seems the friction on radial tires are at the point where the sidewall meets the pavement, and the compression of the tire upon road contact rolls the sidewall tread under the tire, kinda sorta, hence the reason running low tire pressure increases fuel consumption, it causes even more of the sidewall to be rolled under and scrubbed. The advantage of singles is there is only two sidewalls per tire/wheel set up to cause friction, as opposed to four sidewalls to cause friction on dual wheel setup. Multiply that eight times...rather substantial difference.
You're screwed when you have a blowout, with duals you can limp on one tire to get the other fixed. With the super singles you better have a spare, tools, and a driver that's not too lazy/stupid.
Freight Company's are using them.Read where one driver sat for four hours for repair truck to show up with a tire.O/O can carry a spare.
Yes, that has been mentioned previously. And although that may be a point of consideration for individuals who operate trucks, I would guess it's a managable expense for large fleets, who are the ones most likely seen using these tires. If the fuel savings are substantial for a trucking company that consumes fuel in thousands of gallons per year, the cost of occasionally sending out a tire truck to repair a flat on the road is an insignifacant expense compared to the fuel savings. Just my guess.
Reduced friction, lighter weight in most cases and believe it or not reduced air drag are what contribute to the fuel savings. Blowouts are caused by improper inflation pressures, a super single is susceptable as well. More diligent monitoring would be required.
It's all about fuel economy. Guys running them were reporting upwards of .5mpg improvements without any other changes compared to other trucks in the fleet. The super singles are susposed to also have better wear on them. But im not sure about that.
This is the most information I've found in a published article thus far. It seems it's mis-information to call these new single tires "super singles", as that term is traditionally given to the severe service single tire used on construction vehicles. It seems those tires have thicker side walls and tread to reduce tire damage from curbing and gravel chips at jobsite conditions. They also run at higher air pressure, 130 PSI, whereas the new wide base singles run around 100 PSI. Appearantly, these new wide base singles are a completely different tire than the old super singles. http://www.truckline.com/Newsroom/White Papers/New Generation Wide Base Single Tires.pdf
As for the tire blow out issues how often with todays tires do you see a blowout? I see VERY few and the tire Manufactures claim most of those are caused by uninflation. What I do see is auto inflation systems on new trucks and trailers so tires are always at correct PSI. With these systems in place even a small leak can be kept aired up until you find a tire shop. I told that tire PSI monitoring systems are becoming manidated on new trucks in the near future because of safety concerns of underinflated tires.
Here's a easy to use system for keeping an eye on tire pressure: http://www.linkmfg.com/catseye/catseye.html
with TPMS (Tire Pressure Monitoring Systems) being spec'd in almost all new fleet trucks it makes keeping them inflated much easier. Your not going to get some wheel holder out there to change the tire himself thats for sure. A very well spec'd fleet i know thats on the cutting edge of technology is pushing a FLEET AVERAGE of 10mpg. they run all the crazy advanced areo devices, wide based tires, wheel covers, side skirts, areo tractors, Single drive axles with lockers and auto deflate on the tag, boat tails Direct gear 10spds and super high ratio rear ends. cutting edge fuel economy stuff.
Probably without pay too. A spare would be heavy compared to a single tire(not a super single).
If have of these companies were concerned about fuel savings they would put their trucks on trains or build stuff in America again and not have to rely on containerships from China for our daily bread.
How do we go from a conversation about fleets useing single tires to a rant about stuff being made in China?
Long ago discussion of the topic. Less long ago, (but shorter) discussion. Interesting to compare the information being shared in this one, to the threads from 5 and 6 years ago...
The replacement cost is something to consider as well. If i recall correctly, the super single is cheaper than 2 duels by about 30% Has anyone driven a truck with singles on the drive tires off road on jobsites? I am curious how they do in soft/muddy situations and also how they do in sandy "wheel hop" material.
Our new Mack Granite grease trucks have singles on them. They seem to get around a little better off-road on the job site. I have heard they are real scary to run in the snow/sleet. I will try to get some pics of them if you guys want to see the trucks.
EGS, of course we want pictures.... Here in my area, I do see trucks with super singles on trailers, and the occasional rig, but I don't think they are that popular because of the winter conditions.
Some of the dump truck guys run them because they dont drag as much mud on the street. Im told they get around prety good off road
That is what I have heard too
When I was talking blowout I was not talking about defective tires or inflation. I guess I failed to mention debris in the road and some road conditions in general. I have seen some super singles that were re-capped and they make quite the mess when they explode. I guess that's the chance you take. Personally I wouldn't run them, could you imagine one on the rear axle of a frameless dump? At least with 2 you have half a chance. But I guess if all did was stay on the road and not going into quarries, landfills, scrapyards, etc. you'd be alright. Also like I said you will have to carry a spare(extra weight) or wait on a service truck. I guess I'm old school trucking when it comes to improvising to get back on the road and making money. I doubt a fleet driver carries a 20 ton jack, cheater pipe, or a lug wrench, let alone get paid while waiting. As far as safety concerns your pre-trip inspection mandates a tire inspection. There's always a new gimmick or law in trucking to get into your pockects. If you cannot thump a tire and determine that's it close to proper inflation by the sound then you couldn't pass the hearing test on a DOT physical. A good PSI monitoring system is a good driver who checks his tires with a good tire gauge.
Ok lets fire up an old thread. Can some one tell me how much lighter vs 11-22.5 duals with aluminum rims. how do they perform in soft ground. How about longevity, will one out last the other under normal use? Would be on a trailer not the tractor. Anyone have any actual facts on comparing the two set ups.
In 86 I ordered a new pup trailer with super singles. It was fine going down the highway. It was a little frightening dumping on the fly on a fill. It lacked the stability of a "conventional" arrangement. It never went over, but the grade hops gave it a wide berth. I eventually put 11/24.5s on it. I think that if I had ordered wider axles the stability factor would not have been an issue. The trailer box was aluminum, steel frame extendable reach. It handled pretty well on "pumpy" fills. It did not cut in when jackknifing to dump. They also do not drag a bunch of material out on the road and "rocks stuck in the duals" are not a problem. I had hooks on the frame above each axle. If I developed a flat empty I would chain the axle up and go to the tire shop. I checked the pressures weekly and did not have an issue. I have a few images of it. I will try to find a couple.
Know a Few locals with SS tires on dump trucks and pups, use them for Priority ON HIGHWAY primarily deliveries, still have duals set ups they take Off Road as the damn things are hogs on ice in any slime or slick. MD hit on the stability issue, watched as another local Dump Trailer service here using them emptied trailers on a grain haul, NO THANKS, lean and bobble even with air suspensions dumped, drivers say they never get used to it.
For a set of dual tandems, on the rear of a trailer, you will save about 700lbs. 4 super singles mounted=1036lbs. 8 x 22.5's mounted should be around 1750 lbs. So you would gain 700 lbs of payload with going to super singles. I would never put them on a tractor. Snow and mud are a no go. I wouldn't put them on a trailer either, personally, because I have been known to have a low tire, and I much prefer dual's in that situation. I could see super singles, if you were hauling a particular counterweight arrangement for a large crane, and had already a day cab light truck, and aluminum trailer, and had to have another 700lbs to get legal. But I would try every other way to save weight, before I went to super singles. I just don't like them.
There's a commodity trucking business around that runs super singles on all of their rigs, but these are 8 to 11 axle rigs so the weight savings adds up a little better. Have them on their tractors too, but they rarely get into off road slop. They usually make their scheduled deliveries all year long from my experience. Trailers are either auger bottoms with stinger or live bottom belt unloaders.
SS are bad to eat a rim when they have a blow out. Maybe related to brake application?
A friend of mine runs a dozer at a large landfill, according to him they are not very good off-road and they spend a lot of time pushing those trucks. Apparently in the rain not so good either. I run 24.5 and don't understand all the 22.5 rims and tires out there. Cross the boarder into Massachusetts they still run 1200 24 tires and split rims, seen new macks with them.
Major fleets like them because they are cheaper both in overall cost and fuel. I would never have them on my truck, because of the maintenance issues and potential down time. When I am 4-5 hours from the nearest tire shop, I want to be able to limp along to get closer. When you have 200+ trucks and trailers it might make sense, when you have 5 or less I do not think it makes sense to run them.
Only place big single tires look good is on a steer axle.
Would they maybe work good for site work on fresh clay?
I agree IF the truck has an 18 or 20 front, however, if you put super singles on a 12k front you are a poser!