19.5 Tires

[Flying W]

Does anyone out there have any experience with 19.5 tires or some links to sites with information? I've been trying to find out if the smaller size tire will affect the lifespan, fuel mileage, load bearing capacity, or gearing for a truck.

There is all kinds of information on low profile tires, super singles, and converting from steel to aluminum wheels, but I can't find much about 19.5 tires. Any help is appreciated. Thanks in advance.

[asdfghjkl]

I have run them for years on my car hauler. My experience has been that if you get 100k miles out of 19.5 steers consider yourself lucky. Drives 150k. trailer 225k. If you go with 19.5's go with Michelin, they are far more expensive but you'll definitely see a return versus Goodyear or Continentals.

[asdfghjkl]

Plan on carrying a spare as most tire centers don't stock them unless your near a large city.

[GMAN]

I had them on my car hauler trailers. They heat up more than the larger tires and don't last as long due to the heat. If you plan on putting them on your tractor it will change your gearing so that your speedometer will not be accurate. The only advantage in having them on a tractor is if you haul high loads such as a car hauler and full size vans on the head rack. Other than that I would go with the taller rubber. I prefer 24.5 tires on a tractor. If I were still pulling cars around I would go with smaller tires due to the height. One other thing to keep in mind is that you will likely blow more tires in summer if you run in the desert much. It is best to keep your highway speed down and stop more frequently to allow them to cool down when running in hot climates. I had a tire dealer tell me once that the major cause of tire failure is heat.

[Rev.Vassago]

When I was doing HHG, I believe that's what was on the trailers. I'd never put them on a truck, for 2 reasons:

1. They'd look stupid, and
2. More tire rotations = more fuel.

[GMAN]

Swift ran them on some of their trucks at one time. I don't remember the reasoning, but it was needed for one of their accounts. They really looked strange going down the highway. I haven't seen one of them in some time. And you are correct, Rev, they would most likely burn more fuel since the tires would turn faster. You might be able to change the gearing in your rears, but that seems like a lot of expense for no real advantage. The tires might be a little less expensive, but you would spend more in fuel and tire replacement.

[Flying W]

"One example is the use of 19.5-in. tires on auto transporters. Non-standard brake packages, wheels, axle ratios, and other components are required, but resale value is a low priority since these specialized vehicles have very long lifecycles and are resold to limited market. The productivity considerations of transporting taller vehicles (SUVs, for example) within legal height limits, as well as ground clearance requirements to safely negotiate railroad crossings, define the height envelope dimensions of which these tires are an integral part." It's not much, but I found this at Tires of the future.

If a 19.5 would get less mpg because of more turns, then wouldn't 24.5's get better mpg than 22.5's which from what I have seen isn't the case (I attribute that to less rolling resistance of the smaller tires, but am not 100% sure)? What GMAN said about the heat is something I was worried might be the case (less surface area to spread a load/heat over). I would think the smaller tires are likely rated at a lower payload rate. Can anyone confirm this or disprove it(say even the 22.5's vs. 24.5's)?

[GMAN]

I have one truck with 24.5 tires and another with LP 22.5. The one with the 22.5's gets a little better fuel economy. I am not certain that it is the tires that makes the difference. I believe the T600 with the 22.5 has higher gearing and is more aerodynamic than the 9400 which has the 24.5's. Both have the same CAT engines but the T600 will get about .5-.75 mpg more than the T600. The T600 is also about 1500 pounds lighter than the 9400 and has a super 10 rather than a spicer 10 speed. In order to be completely accurate in calculating the difference in fuel economy you would need to have identical trucks with the same drive trains and the different size tires. There is a website (I don't recall the web address) that shows the different types and sizes of tires and compares fuel economy. I believe they stated on their site that the LP 22.5 tires got better fuel economy than the 24.5 due to rolling resistance. I am not sure that I buy that, but that is what I remember about the website. I prefer the taller rubber. I think they ride better than the smaller 22.5 tires. I know they run a little cooler due to the larger size and displacement of the heat over a wider area. When I bought my step deck I wanted the 19.5 tires or 17.5 tires. I bought the 255/22.5. There were primarily two reasons for my decision. First, the tires would likely not last as long as the larger tires and were not as readily available. Second, brakes were larger on the larger tires. I felt that it would be better to have the larger brakes based upon where I was running at the time. Perhaps someone else knows the web address for the tires. It may have been Michelin's website.

[BanditsCousin]

I run 19.5's on my van and a 17.5 on my pusher axle. They look like they are about to ripoff the rim when I do tight backing mauevers. They aren't too obsolete at the major truck stops like Petro. I got a lot more life out of 22.5's on a moving van than 19.5's.