Frequently Asked Questions

In DOT number, I understand first two digits denote plant code and last 4 digits for week & year. Is the two digits after plant code indicates tyre size? If so, how do I understand the coding?

U.S. DOT Tyre Identification Number... This begins with the letters "DOT" and indicates that the tyre meets all federal standards. The next two numbers or letters are the plant code where it was manufactured, and the last four numbers represent the week and year the tyre was built. For example, the numbers 3105 means the 31st week of 2005. The other numbers are marketing codes used at the manufacturer's discretion. This information is used to contact consumers if a tyre defect requires a recall.

Our 33000 lb class A motor coach came with expensive 10R22.5. The 11R22.5 is standard, easy to get and cheaper. What is the difference?

Basically, a 10R22.5 is like a size 10 shoe and an 11R22.5 is like a size 11. Although the dimensions can vary slightly from brand to brand and from one tyre type to another, the 11R22.5 is around a half inch taller and a half inch wider than a 10R22.5. Since it is larger, it can carry more loads. Each may be mounted on a 7.5" wide rim or an 8.25" wide rim. Before buying the larger tyre size, make sure that there are no clearance issues with the vehicle.

I’m considering storing my truck.. If I leave my truck in storage for 2-3 years, and it remains stationary for the entire time will the tyre (11K miles on them) be permanently damaged?

If you plan to store a vehicle for a long time, it would be best to get the tyres off the ground by putting the vehicle on a good set of jack stands for the storage period.

I just noticed a bubble on one of my front tyres. I’m taking it back to the dealer to be checked. How dangerous is it to continue to drive it in this condition?

It all depends on the size of the "bubble" and the reason it is there. Tyres can often have a raised area up the sidewall from the bead area where a splice is made in the ply material during the building process. This would present no problem whatsoever as the tyre is actually "stronger" where the splice is made. But, if the bubble, bump or bulge is caused by some sort of ply separation and the sidewall rubber is bulging because the air in the tyre is pushing it out, you should be concerned and have the tyre replaced.

What effects do retreaded drive and trailer tyres have on fuel economy in comparison to new tyres?

Goodyear recently introduced a line of new tyre and retread products to enhance fuel economy. We call them Fuel Max. You can purchase steer, drive and trailer tyres that will help enhance the fuel economy of commercial trucks and retread drive and trail axle tyres with treads made with the same fuel-efficient properties. Other tyre manufacturers and retread manufacturers make fuel-efficient products, also. We cannot speak for them but, in the case of Goodyear, our goal was to design new tyres and retreads to perform equally in all the ways that performance can be measured.

Is there anything you can other than replace flat spotted tyres that were caused by sitting too long?

We assume you mean a vehicle that has not moved for a very, very long time. Just sitting overnight can often cause the tyres to have a slight flat spot on each tyre that will tend to go away within about 15 minutes of highway travel. Vehicles that have been sitting for months or years can cause a more severe flat spot that just won't go away. We can't image anything you could do to get rid of these kinds of flat spots.

What is the primary seal of any truck tyre? I hope the answer is the metal valve cap.

We suppose it is a matter of opinion but, we think you are correct. A metal valve cap seals the valve and dirt, water and other undesirable elements from getting into it.

What are the advantages or disadvantages of an all steel tyre vs. a non all steel tyre?

All steel tyres (tyres with a steel body ply and steel belts) are considered "commercial tyres" at least in Goodyear terminology. This means that they are intended for use on "working trucks" on a daily basis. Tyres with fabric body ply and steel belts are called "consumer tyres". Occasionally, these tyre might be used in some sort of working environment but, for the most part, they are on vehicles that provide transportation to a driver and a passenger or two.

I have a 2006 Freightliner 265 wheelbase. I run with approx.31000 lbs on the drives about 85% of the time. What is the best inflation pressure for wear and mileage??

The key to your question is the comment about running 31,000 lbs, 85% of the time. We assume this means that 15% of the time, your drive axles are loaded to something more than 31,000 lbs. Unless you plan to raise and lower your pressures based on the load being carried, you should sent your pressures based on the highest loads you expect. For a tyre, overloaded or underinflated has the same effect, potential casing damage even if it happens only a small percentage of the time.

Does a bias tyre wear differently from a radial tyre when under or overinflated? For instance, does a bias tyre wear more in center and a radial wear more in the edge when under inflated?

Overall, we think the bias tyre's footprint shape is affected more by inflation pressure than the radial tyre. This is due to the belts under the tread of the radial that create a flat tread surface in an over inflated or under inflated situation. So, given the same under inflated condition or over inflated condition, the radial tyre's wear would be fairly uniform across the tread. The bias tyre would tend to "crown out" if over inflated and "dip in the center" if under inflated leading to center wear in the first case and shoulder wear in the second.

I drive a dump truck hauling slag on a daily basis. Small pieces of slag is getting in the tread and working its way into the tyre (sometimes all the way to the cords if I don’t notice it and remove it). Have you ever heard of this and do you have any solutions?

Stone drilling is, unfortunately, common for tyres that travel "off highway". Goodyear and the other major tyre manufacturers make tyres for off highway applications. If you are using highway tyres in an off highway situation, that could be a large part of your problem. Check with you tyre supplier to see if the tyres you are using are the one's best suited for the roads you travel.

What tyre pressure should I run on the steer axle of a line haul tractor?

The proper inflation pressure for any tyre is determined by the highest load it is most likely to carry. Tyre companies publish load/inflation tables. To see these tables for Goodyear tyres go to Of course you need to know the load on each tyre. With a vehicle loaded, have the truck weighed axle by axle. Divide the steer axle weight by two and any other axles by the number of tyres on each axle. If it is difficult to measure just the forward or rearward axle of the drive or trailer axles, weigh the tandem axle load and divide by the number of tyres (usually 8). For the size tyre you are running, find what inflation pressure corresponds to the load on each tyre. When in doubt, round up to the next highest pressure. It is always better to have too much inflation pressure rather than too little.

I’ve heard that a ribbed steer tyre was an appropriate choice even when drives were lugged. I drive several types of 4-wheel-drive vehicles in a rural, often off-road setting. Recently, all the tyres were replaced, but, over several objections, the lugged steers were replaced with ribbed tyres while the drives stayed lugged. All our operators have complained about the change in handling, saying that the vehicles are difficult to get into trim so they drive straight on asphalt, without a lot of manual steering correction. We don’t put a lot of miles on these tyres, so I don’t know if breaking them in would have any effect on the handling. We feel we’ve sacrificed traction for a rule-of-thumb. For this application, should we be using the ribbed steers, or are lugged steers the appropriate choice?

There are exceptions to every rule. In most cases, commercial vehicles traveling on paved roads work best with rib steer and trail tyres and lug drive tyres. This combination of tyre types provides the best compromise in for handling, traction and tread wear. Special cases (like extended usage off-highway) may require a different combination of tyres. Also, it may be a matter of the drivers getting used to the different feel of the rib tyres on asphalt.

Is balancing of truck tyres important?

With the airride suspensions and cushy driver seats, it takes a lot of imbalance for a driver to feel an unacceptable vibration. Our tests have shown that it takes about 20 oz of imbalance for the driver to feel it. However, tire/wheel imbalance does take a toll on vehicle components. So, it becomes a value judgment.