OK, this is perhaps a stupid question, but I'm being driven to distraction by these tires.

I have a 6MT coupe with the original Pilot Sports. What, exactly, would be the consequence of rotating the front tires left-to-right without dismounting? I KNOW these are unidirectional tires, and they would be rolling opposite from the way they're designed. So what? What's the consequence?

Is the unidirectional design significant ONLY to the tire's ability to disperse water? If that's the case, maybe I'll rotate them as described and just leave the car home in the rain (or drive in reverse when the roads are wet :-) )

The tires noise is really getting on my nerves. I've had the car aligned, and had the tires dismounted and swapped left-to-right. But there was already significant cupping on the inside (now outside) edges. I just have this wild idea that if I rotate 'em and drive then "backwards" for a couple of thousand miles, the wear patter would "reverse" the damage. Am I completely out of my mind?

 

I'd say that it's not worth the risk. I don't know about the physical mechanics of directional tires, but say you did reverse them and then got into a serious accident. You could bet that you insurance company wouldn't be paying off anytime soon because you were knowingly using your tires improperly.

It should only cost like $40 to have them remounted, I'd play it safe.

Ivory Coupe 5AT
Z tube, K&N drop in.
Fujitsubo Y pipe...

 

The tires tread design is there to help aid in performance handling, but also in water dispersion. Running them backwards will actually pump water under the tire. This is really bad and can cause the car to hydroplane. Run them facing forward bud :-)

2003 BLK/BLK 6MT Injen, clear corners, Eibach sways and springs, tint
My G on a photo shoot. More to come!

 

90% of hydroplane speed is a function of inflation pressure and soft tread compound.
The higher the psi the greater the molecular force between the tread and the road. But the front pile of water must escape somehow.

"A formula that comes close to predicting the speed at which you will hydroplane, assuming at least .2" of water on the ground, is: 10.27 * Sqrt(tire pressure) which shows that if your tires hold 35 PSI, hydroplaning can be expected at 60.76 MPH, while tires with 41 PSI of air in them should expect hydroplaning at about 65.75 MPH. Another formula that is somewhat more accurate, though much harder to calculate, is: 7.95 * Sqrt(tire pressure * contact patch width / contact patch length). This formula shows that the wider the contact patch is relative to its length, the higher the speed required to support hydroplaning.)"

Directional tires do help a little but not as much as many think going straight ahead, they do help on turning in the rain more than going straight, but it was a LOOK created to sell performance IMAGE tires primarily.

One may ask if directionals are so good in rain why are they not used in airplane tires. But then airplanes land straight and don't turn until almost stopped.

At one point tire rack did some test on what changes if any reversing the direction created . THEY HAVE REMOVED THIS TEST FROM THEIR WEB site recently.

Personally I wouldn't do it because the internal belts might shift and threads go bong from reversal stresses.

Notice that Michelin rates [wet performance] its non directional PS2 higher in the wet than it's directional PS.
http://www.michelinman.com/catalog/index_3.html

 

My original tires did the same thing, cupped at about 5K. I had them dismounted and moved side to side, but that really didn't help matters. In the process, the dummies at the dealership did remount my rear tires backwards, and I didn't notice it for a few weeks. I couldn't tell any difference in performance. Finally the tire noise was unbearable. I replaced them at 11K with Bridgestone S03s. Wow, what a difference. They perform great and they are smooth and quiet so far. Infiniti has cost owners lots of grief, not to mention expense, with those lousy Michelins.

 

"One may ask if directionals are so good in rain why are they not used in airplane tires. But then airplanes land straight and don't turn until almost stopped."

Furthermore, the ailerons and stabilizer are doing all the work during the hydroplane speed anyway. In general aviation, tires need to withstand dry rot and going 100 to zero in a nanosecond more than anything.

Powercat,
Report back to us on the noise of your Bridgestones after 11K. I suspect they'll be as noisy as your Pilots provided you treated them similarly. I'd hardly call the Michelins lousy. The Pilots and S03s are both great tires, although the Pilots are considerably lighter.

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5/Crawford Cats

 

Another thing to remember is that the paint on our wheels
are very soft. Most tire shops will scratch the rim when
they remount, so I would not recommend remounting the
tires just to rotate them.

Use them up until its to the wear indicator (if there is one
on the pilots) and then just get new tires.



2004 G35C 6MT Bright Silver

 

I'm sure directional tires are only better when compare against brand new non directionals, by the time both are half worn [6/32"] 10>2/32".............it is debateable which is the better wet stopper. By then a pure function of tread compound softness.

The 2/32" wear bar is the legal limit, performance enthusiats would be well advise to replace long before the wear bar! IF wet weather performance - hydroplanning or braking is a consideration.

 

Heard from a friend that works at a tire center that no matter what you do, you cannot ever correct tire cuppling/feathering. The tire is pretty much ruined.

 

Agree, all directional [sound optimized new] get feathered and noisey as the miles pile up beyond the 8,000 mile design point............just a fact of engineering to use tread depth as a cancelling function for acoustics.

Owners want performance as long as they don't have to pay for tires and brakes [plus maintenance without replacement], then they use any method to try to shift the burden [costs] back to factory. People buy 260-300 HP then complain about gas mileage.

 

you CAN rotate the tires... remove them from the rim and slide the left to the right, and vice versa... ta-da!

04 / Black Obsidian / Graphite Leather / aero / splash / prem / perf / cc / 22%tint
z-tube / k&n drop-in / Eclipse AudioVideoNavigation 2454 / side-blinker mod

 

Quoted by Q45tech - "Agree, all directional [sound optimized new] get feathered and noisey as the miles pile up beyond the 8,000 mile design point............just a fact of engineering to use tread depth as a cancelling function for acoustics.

Owners want performance as long as they don't have to pay for tires and brakes [plus maintenance without replacement], then they use any method to try to shift the burden [costs] back to factory. People buy 260-300 HP then complain about gas mileage."

Sorry Q45tech, I'm going to have to disagree regarding tire feathering above 8k miles. Reason is that some of G35c did not experience tire feathering, and some that did experience tire feathering is due to misalignment from the manufacturer. By the time that the manufacturer/dealer properly aligns the wheels with the tire feather, the tires are already ruined which I think should be the responsibility of the manufacturer/dealer to replace the tires.

Manufacturer and dealers give consumers alot of crap also which they don't want to take responsibility/burden of their problems.

 

Thanks for everyone's feedback. It sounds like running the tires "backwards" or against the indicated direction is out.

I'm at 15k miles. I'll just live with the noise for now - all indications are that, even with the cupping, I'll get 20k miles out of these tires (the original Pilot Sports), maybe a tad more. Look for another post from me in, oh 5 months, asking about what new tires to buy (maybe by then Michelin will be making PS2's that are appropriately sized for the 18x8 wheels!).

Steve

<P ID="edit"><FONT class="small"><EM>Edited by steveinmd on 08/27/04 06:23 AM.</EM></FONT></P>