Originally Posted By: CivicFan
Yesterday I was talking to a trusted mechanic who works only on German cars and does only suspension work and tire installations.
When I told him that I was changing my philosophy about tire rotations, he said that rotations, even though oversold, are not necessarily a bad thing. Some of the things he said were:
- rotate tires every 7,500 miles or so, not more frequently, especially if you are paying someone else do it. If it's done more frequently, your car is never with a "broken in" tires and doesn't handle properly. This, obviously, is about cars that are for performance........
On the first item: While he does have a point that it takes some time for a tire to wear to the point where that wear pattern needs to get "undone" by rotating to another position - AND - while he does have a point that you will lose some grip for a while after rotation, I think it is over-stating the interval. Vehicle manufacturers tend to include tire rotation as part of a maintenance schedule that includes quite a few different items for the interval - meaning the interval is somewhat arbitrary.
Tire manufacturers say that in absence of instructions from the vehicle manufacturer, use 5K to 8K as the interval. This seems like a reasonable value - meaning I think he is wrong that you should "wait" for 7.5K. It ought to be a convenient interval.
Originally Posted By: CivicFan
.......
- it's OK to rotate directional tires and have them spin against the direction noted on the sidewall. Both the front and the back can be criss-crossed in a pattern that resembles an X
OK, above this post is a semi-retraction - and the only comment I have to make is an observation:
I hear this type of stuff all the time. Imprecise wording - sometimes even misleading wording. I hope everyone takes a lesson to be careful to say exactly what you mean.
- AND -
Yes, the only property affected by having a directional tire rotate the wrong direction is wet traction. Grip and wear are unaffected.
Originally Posted By: leeharvey418
Tire Rack
tested the theory that directional tires are substantially worse in the rain when run 'backwards'. In a nutshell, as long as the pavement isn't up to the point where some non-directional tires would begin to hydroplane anyway, there's practically no difference in wet traction with respect to rotation direction.
I am still of the opinion that Tire Rack's test pad doesn't have enough water depth. When the company I work for brings the Tire Rack folks to the Proving Grounds, we have repeatedly pointed out that we get differences in wet performance that they do not get.
Hokiefyd's post says Tire Rack agrees with that!
But you have to wonder why they bother to report results when they know the results aren't accurate!
- But -
Way back when - the company I work did perform the test and got about a 10% difference in traction. So it's not a lot, but it is there.