Tire Rotation, Devil's Advocate.

[Chance]

Other schemes that appear common. However, in some cases rear inner wheels and outer wheels are not the same.

[Oneilkeys]

Originally Posted by dstankov

Actually not rotating from side to side is not an "old wives tale". In 2001 I bought a Mustang SVT that had high performance Goodyear Eagles on it. The tires were directional and had arrows molded into the side walls to indicate the direction of rotation. If those tires were to move from one side to the other they had to be removed from the rims and remounted on the other side's rims. The directional reasoning on the tires is the tread design and the way in which the tread moves water and snow. Directional tires are still made today by quite a few manufacturers.

Google directional tires and you will get more info than you may want.

That's true. There are some snow and all wx tires that are designed to only rotate one way.

[Oneilkeys]

Originally Posted by Chance

Other schemes that appear common. However, in some cases rear inner wheels and outer wheels are not the same.

According to my "tire guy" the original tire rotation guidelines date back to the initial radial tires (think Firestone delamination) when the tire manufactures did not really know how radial tires were going to wear and last, so they erred on the side of caution and it became "gospel". A similar thing happened with fiberglass boats. The first ones were built like "tanks" because no one was quite sure how strong and long lasting fiberglass really was.

[EA37TS]

Originally Posted by Chance

Yeah, I don't know where the "don't change direction of rotation" for normal tires came from, but this Ford manual clearly shows rotating tires from one side to other. I also find it interesting that they make reference to readjusting air pressure after rotating, which normally applies to a front-to-back rotation.

Technically air pressure should be set based on 4 corner weights and not on axle weights. That is the reason Ford recommends adjusting the air pressure when rotating from side to side.

It is, however, hard to find a place that can do 4 corner weighting so most are stuck with axle weights and the same air pressure on each side of the axle.

[EA37TS]

If interested here is the link to a document about Michelin RV tires that talks about maintenance and care to include cleaning and cautions about tire dressings.

The doc is too large to post.

https://www.michelinb2b.com/wps/b2bc...s_Brochure.pdf

[Chance]

Originally Posted by dstankov

Technically air pressure should be set based on 4 corner weights and not on axle weights. That is the reason Ford recommends adjusting the air pressure when rotating from side to side.

It is, however, hard to find a place that can do 4 corner weighting so most are stuck with axle weights and the same air pressure on each side of the axle.

Dave, the Devil is in the details.

Ford also warns against lowering air pressure to improve ride, etc... If you follow that line of thought, then tires should be operated at the designated pressure stated on placard, not on what we think is necessary based on actual 4 corner weights.

If we accept that's what Ford is recommending, then the air pressure adjustment statement is not consistent. They can't have it both ways.

[EA37TS]

Originally Posted by Chance

Dave, the Devil is in the details.

Ford also warns against lowering air pressure to improve ride, etc... If you follow that line of thought, then tires should be operated at the designated pressure stated on placard, not on what we think is necessary based on actual 4 corner weights.

If we accept that's what Ford is recommending, then the air pressure adjustment statement is not consistent. They can't have it both ways.

In the F53 manual; Ford talks about recommended cold inflation pressure and maximum tire pressure. They state in a number of places to never inflate below the recommended cold inflation pressure listed on the Safety Compliance Certification Label which is located in the vehicle.

They also say:

Maximum Inflation Pressure is the tire manufacturer's maximum permissible pressure and the pressure at which the maximum load can be carried by the tire. This pressure is normally higher than the manufacturer’s recommended
cold inflation pressure which can be found on the Safety Compliance Certification Label or Tire Label.

Basically they have it both ways. Set the pressure to the tire manufacturers recommended pressure based on weight or the recommended cold inflation pressure which ever is higher.

Ford gives you the minimum pressure while the tire manufacturer sets the maximum pressure.