Run Flat Tires

The owner's manuals for all recent BMW's generally recommends not rotating tires - run flat or conventional, unless you do it very frequently (every

3,000 miles, IIRC). I rotated the run flats once at 16,000 on my Z4 with no problems. Naturally, the rotation should be front to rear, not "X".

Tom K.

yes, if you can.

"it depends"

For example; tires on an NSX Accura cannot be rotated, regardless (different sizes front/rear)

if you drive once a month and the alignment is perfect; then it's probably not needed as often as if you drive daily or your alignment is somewhat out of whack.

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And on the NSX, they're actually four different tires, left and right, front and back. You can't even dismount the tires and swap between the left and right rims on the front or the back; the inside and outside sidewalls' stiffness are different for each side.

It's possible to tune the NSX's suspension alignment such that you will get the ride and handling of your life, but it will eat the rear tires in 2,000 miles, and the fronts in 5,000 or so. Ask me how I know this...

well; that's true -- but the point is some cars you can't...

but the fact that their "run flats" doesn't specifically preclude them from any of the standard maintence

and if youv'e ever driven on them "flat" you'd realize they are regular tires with softer "rims" inside that let them continue on if the air lets loose.. (at least the ones I have experience with)

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Which brings up a good question. If you have a car with a staggered set-up (wider rear tires than fronts) on a car like a BMW with a healthy amount of camber, the insides of the rears always wear out first. Assuming you have either directional or non-directional tires that are

*not* also assymetrical, why couldn't you dismount the tires from the wheels and remount them on the opposite sides when they begine to show wear on the inside? I would not want to do this every 3-4 k miles, but if you did it once at the half wear point (whatever that is determined to be) it would seem that you could significantly improve the mileage you get out of those expensive wider high performance tires at a paltry cost.

and they think this is an original set-up.............back in 1974, my Ford Anglia 105E had different tyres on each wheel.............

Well, so did my '63 Cortina. They *were* all remould crossplies, though. They used to cost about £5 each, as I recall.

I think you would end up suffering in performance doing this.

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yes same here, remoulds and I was only earning £25 a week..........and my mortgage was £100 a month...........I paid t'morgage, er indoors paid fer fud.

Aye, those were the days. Kids today don't have a clue how hard we had it back then...

Why? Please explain your thinking. The tires would still be rotating in the same direction, so no problem there. And with non-assymetrical tires there is no inside or outside edge of the tire per se.

£5 in the 60's makes them (judging by house prices) about £50 each. That isn't cheap for a s**te tyre!

You're saying that crossply remoulds are s**te tyres? You obviously weren't driving used cars in the 60s, that's all I can say.

they're not 'different', they are rotational. nothing new. By the way, the M3 also has different sizes front and back and also rotational tires.

possible on any car with independent suspension.

I have never experienced this. Keeping the tire pressure healthy is a great help.

Yes, but the M3 doesn't have a different *part number* for the left and right tires, does it? You can swap the tires side to side on the M3 rims. You can't do that on the NSX.

But it's pretty pointless on most cars.

Those tire eating alignment settings are actually the first, original Honda alignment spec. It's a long story, Google can tell you if you're interested.

It has nothing to do with tire pressure and everything to do with the camber. Your cars must not have had much camber and/or did not have very wide tires.

Ask anyone with an M3 how long their rear tires last and where they wear out first.

It depends upon *which* set of tires you bought. The OEM tires were unidirectional and left/right. However, some replacement tires were only unidirectional and *NOT* left/right. Those could be dis- mounted and remounted on the other side to "rotate" them, if you really cared to do so. Since the fronts never lasted more than about 12K miles and the rears never more than 6K, there's really no purpose in doing so.

FloydR - former NSX owner.

Stock setting, 275 in the rear. wide enough ?