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The Doctor's Archives

Inflation . Tire Application . Tire Facts . Tire Maintenance
Tire Performance . Tire Specs . Tire Wear . Unidirectional Treads

Dear Tire Doctor,

At what interval should tires be rotated? I drive a 2007 Kenworth T600 with R287 steer and M726 EL on tandem axle drives. All wheel hubs have the Centrimatic® Wheel Balancers installed and the drives have Cat Eyes® Tire Equalizers. I wish to stay on top of maintenance requirements. view reply >>


I have a question about mixing dual tires. Can we run one tire with a load range "G" and the other load range "H"? What about mixing other load ranges? view reply >>

Can storing a vehicle on concrete effect the tires?
Should I put barriers like plastic or other non-porous material
under the tires?  How about the effects of continuous storage
for several days at a time with use between storage periods?
view reply >>

How long can a tire be stored? view reply >>

For a commercial semi-trailer, how much more life can you expect out of new tires if an alignment is done? They want to charge an extra $25.00 per tire to align and I don't think I will see an extra $200.00 savings out of the tire from the wear and tear. view reply >>


Dear Tire Doctor,

At what interval should tires be rotated? I drive a 2007 Kenworth T600 with R287 steer and M726 EL on tandem axle drives. All wheel hubs have the Centrimatic® Wheel Balancers installed and the drives have Cat Eyes® Tire Equalizers. I wish to stay on top of maintenance requirements.

Thanks you! Mike

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Dear Mike,

Thank you for this opportunity to be of assistance. There are a couple of different rotation schedules commonly practiced in the trucking industry.

Steer Tires:

1. One common practice is to rotate steer tires side to side when there is a 3/32nd difference in remaining tread depth between the left front tire and the right front tire (Remember: the left front tire normally wears more quickly than the right front).

2. Some fleets rotate the steer tires side to side every PM. While this is more labor intensive, it helps ensure tire rotations are performed on a regular basis and before irregular wear has a chance to set in.

Drive Tires:

1. One common practice is to rotate the drive tires when there is a 3/32nd difference in remaining tread depth between the axles (the rear axle normally wears more quickly than the front axle).

2. Some fleets prefer to rotate drive tires at every PM. Again, this is more labor intensive, but assures rotations are done an a regular basis.

3. Many fleets highly recommend rotating the drive tires after 9/32nds to 10/32nds tread have worn. (For example, rotate M726 EL tires when they average 22/32nds tread depth remaining.) In this case the tires seldom need to be rotated other than this one time.

Just as important as the timing of the drive tire rotations is the method used.

1. The most desirable method of rotation is exchanging the front axle tires with the rear axle tires plus switching inside / outside wheel position. (This would be an “X” rotation on the same side of the vehicle) LFO <> LRI; LFI <> LRO; RFO <> RRI; RFI <> RRO. This method assures a change of direction of each tire that helps control heel/toe wear, and change of axle that compensates for different wear rates between the axles, plus a change of position to control the effect of negative axle camber when loaded.

2. However, method #1 has a drawback. Many trucks are equipped with wheel styles that make method #1 very labor intensive (Polished Aluminum wheels out, non-polished wheels in; aluminum out, steel in; or just the dirt and grime that builds up on the inner wheel making it too unattractive to be rotated to the outer position.) If this is the case, you may want to consider just “X” rotating the tires between the axles. LFO <> RRO; LFI <> RRI: RFO <> LRO; RFI <> LRI. This method at least rotates the tires between axles and reverses direction of rotation, but it does not address the effect of negative axle camber on the inner tires.

3. The least desirable method of rotation is the simple front to back, back to front. This helps equalize the difference in wear rate between the axles, but it does not reverse the direction of rotation so it has little to no effect on irregular wear.

If I can be of any further assistance, please do not hesitate to contact me.

Best regards, Tire Doctor


Dear Tire Doctor,

Can storing a vehicle on concrete effect the tires? Should I put barriers like plastic or other non-porous material under the tires?  How about the effects of continuous storage for several days at a time with use between storage periods?

Thanks for your help on this subject. 

Best Regards, Len

^ back to top

Dear Len,

Thank you for contacting Bridgestone and allowing us to assist you.

First of all, regarding the effects of storage:

A cool, dry, sealed garage is your best condition for storage, however, it is realized that this is not often an available option. Concrete is not the tire enemy some people think it is.

We would recommend the following steps in storing a vehicle:

1. Make sure the floor / ground surface is free of any petroleum product contamination (Oil, grease, fuel, etc.) since petroleum products will attack rubber and can cause significant damage to compound characteristics.

2. Thoroughly clean your tires with soap and water.

3. Place a barrier such as plastic, cardboard, or plywood between the tires and the ground surface.

4. Cover your tires to block out direct sunlight and ultra violet rays.

5. Do not store the vehicle in close proximity to steam pipes, electrical generators or animal manure since these accelerate oxidation of the rubber.

6. Make sure your tires are fully inflated with air.

7. When the vehicle is ready to go back into service, inspect the tires for excessive cracking in both the sidewall and tread area and check all tire air pressures. Tires will normally lose about 2 PSI per month so you should expect to find the pressures lower than when you put the vehicle into storage. Re-inflate the tires to the correct air pressure before operation.

Now, about the effects of time:

Yes, rubber compound does slowly change over time, becoming "harder" as it ages. But unless we are talking years, this would be virtually undetectable. However; the most likely effect of storage will be:

1. Flat spotting of the tires from taking a 'set' while sitting in one position for an extended length of time. This 'set' may work itself out of the tires after being put back into operation, but not always. This, of course, would result in a vibration.

2. Tires have waxes and oils specially formulated to protect against ozone damage built into their rubber compounds. When the tire rotates and flexes, these waxes and oils are forced to the tire's surface and are thus able to protect the tire. When a tire is stationary, these waxes and oils are not coming to the surface and thus the tire is at greater risk of ozone damage.

3. Several days of non-use at a time is not nearly as detrimental to tires as long storage periods. The tires would still be operated often enough to avoid excessive 'set' and the waxes and oils are being forced to the tire's surface often enough to provide adequate protection against ozone.

Best regards, Tire Doctor


Dear Tire Doctor,

I have a question about mixing dual tires. Can we run one tire with a load range “G” and the other load range “H”? What about mixing other load ranges? Tires are the same size and air pressure (100 PSI). Also do all tires on the truck have to be the same load range? For example, do the steer tires have to match? Can we use different tires on the front?

Thanks, James

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Dear James,

Yes, you may run same size tires but with different load ranges as duals on the same axle provided you inflate all tires to no more than the maximum inflation limit of the lowest load range tire. Keep in mind, the tires must match within 1/4” diameter (3/4” circumference); so if you are running tires of different manufacturers, tread depths or patterns, it would be wise to confirm that they match within these limits.

The same would apply to the steer, as long as the lower load range tire is capable of carrying the axle load. However, it is generally preferred that the steer tires match in all ways possible, and mismatch of this type would normally only be seen in an emergency situation and would be corrected upon return of the vehicle to the maintenance facility.

I hope this has been of assistance.

Best regards, Tire Doctor

Dear Tire Doctor,

Can storing a vehicle on concrete effect the tires? Should I put barriers like plastic or other non-porous material under the tires?  How about the effects of continuous storage for several days at a time with use between storage periods?

Thanks for your help on this subject. 

Best Regards, Len

^ back to top

Dear Len,

Thank you for contacting Bridgestone and allowing us to assist you.

First of all, regarding the effects of storage:

A cool, dry, sealed garage is your best condition for storage, however, it is realized that this is not often an available option. Concrete is not the tire enemy some people think it is.

We would recommend the following steps in storing a vehicle:

1. Make sure the floor / ground surface is free of any petroleum product contamination (Oil, grease, fuel, etc.) since petroleum products will attack rubber and can cause significant damage to compound characteristics.

2. Thoroughly clean your tires with soap and water.

3. Place a barrier such as plastic, cardboard, or plywood between the tires and the ground surface.

4. Cover your tires to block out direct sunlight and ultra violet rays.

5. Do not store the vehicle in close proximity to steam pipes, electrical generators or animal manure since these accelerate oxidation of the rubber.

6. Make sure your tires are fully inflated with air.

7. When the vehicle is ready to go back into service, inspect the tires for excessive cracking in both the sidewall and tread area and check all tire air pressures. Tires will normally lose about 2 PSI per month so you should expect to find the pressures lower than when you put the vehicle into storage. Re-inflate the tires to the correct air pressure before operation.

Now, about the effects of time:

Yes, rubber compound does slowly change over time, becoming "harder" as it ages. But unless we are talking years, this would be virtually undetectable. However; the most likely effect of storage will be:

1. Flat spotting of the tires from taking a 'set' while sitting in one position for an extended length of time. This 'set' may work itself out of the tires after being put back into operation, but not always. This, of course, would result in a vibration.

2. Tires have waxes and oils specially formulated to protect against ozone damage built into their rubber compounds. When the tire rotates and flexes, these waxes and oils are forced to the tire's surface and are thus able to protect the tire. When a tire is stationary, these waxes and oils are not coming to the surface and thus the tire is at greater risk of ozone damage.

3. Several days of non-use at a time is not nearly as detrimental to tires as long storage periods. The tires would still be operated often enough to avoid excessive 'set' and the waxes and oils are being forced to the tire's surface often enough to provide adequate protection against ozone.

Best regards, Tire Doctor


Dear Tire Doctor,

How long can a tire be stored?

Sincerely, Miguel

^ back to top

Dear Migeul,

Thank you for the opportunity to be of assistance. You ask a question that is very difficult to answer in absolute terms.

Generally speaking, there is no set "storage life" for a tire. The acceptable length of storage will vary according to a number of conditions.

Is the tire mounted on a vehicle?

If mounted, is the tire supporting the vehicle's weight, or is the vehicle jacked up off the ground?

Is the vehicle stored indoors or outdoors?

If stored outdoors, are the tires covered to prevent exposure to the sun?

Are the tires stored close to steam pipes or electric motors?

Does the tire see any use at all - even short trips - during the storage period, or is it left sitting in the same position for the entire time?

As you can see, there are too many variables to state a maximum storage life for a tire.

If it is any help, Bridgestone's warranty expires (6) years after the date of manufacture.

If you have tires you need to store, we recommend the following suggestions:

1. Store mounted on the wheels

2. Remove the vehicle's weight from the tires (put vehicle on jack stands)

3. If at all possible, store indoors, away from electric motors and steam pipes

4. If possible, periodically drive the vehicle a few miles to allow the tires to flex, this allows the tires to force to the surface the ingredients included in the rubber compounds that inhibit oxidation.

5. If you have to store the vehicle outdoors, cover the tires so they are not exposed to sunlight.

6. Before operating after storage be sure to check the air pressure.

7. You may wish to consider nitrogen inflation - nitrogen does not seep through the tire as quickly as air, plus it prevents moisture and oxygen (which cause oxidation) from seeping through the tires.

8. After a long storage period, have your tires inspected by a qualified tire technician.

We hope this has been of some use in answering your question.

Best regards, Tire Doctor


Dear Tire Doctor,

For a commercial semi-trailer, how much more life can you expect out of new tires if an alignment is done? They want to charge an extra $25.00 per tire to align and I don't think I will see an extra $200.00 savings out of the tire from the wear and tear.

Thanks, Kevin

^ back to top

Dear Kevin,

That's an interesting question, and one the Tire Doctor has never gotten before.  You could look at it this way: Say a truck tire cost you $300, so a pair of steers would be $600.  If alignment was out and you had to remove the tires, at say 50% of their usable tread life and retread them, that would be $300 of the tires' value you didn't get. Of course you could retread, making use of the casing investment, but if you had gotten all of the usable life out of the tires, the casing investment would be gravy.

If you are married to your trailer, alignment can become even more crucial because if the trailer axles are out of alignment this will affect the total vehicle.  We have a video called Saving Through Reducing Irregular Wear we will send you. You can also find it on this web site under the Tire Care Videos button.  This may be helpful in answering questions you might have.

Regards, Tire Doctor


The Doctor's Archives > Inflation . Tire Application . Tire Facts . Tire Maintenance
Tire Performance . Tire Specs . Tire Wear . Unidirectional Treads

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