Cross rotate tires?

<div class='quotetop'>QUOTE(BrianG @ Jul 29 2006, 08:42 PM) [snapback]294438[/snapback]</div>

I normally rotate from front to rear. Have you checked your tire psi? 35-36 is what they should be at. Anytyhing less will wear some on the outside edges and anymore can wear in the center of the tire.

 

<div class='quotetop'>QUOTE(Tideland Prius @ Jul 30 2006, 01:37 AM) [snapback]294524[/snapback]</div>

Some places criss cross the rear tires going to the front and the fronts go straight back.

Neither of my cars tires can even be rotated. :huh:

 

<div class='quotetop'>QUOTE(Blackfang @ Jul 30 2006, 10:28 AM) [snapback]294584[/snapback]</div>

I work for Cadillac and the cross the rears to the fronts and fronts straight back applies on our cars...however the Toyota manual calls for NO criss crossing so that is what I'd suggest

 

<div class='quotetop'>QUOTE(Blackfang @ Jul 30 2006, 12:46 AM) [snapback]294502[/snapback]</div>

I understand that you work on Toyotas. Have you seen many Toyota Priuses with Goodyear Integrity tires wearing out in the centers before they wear out on the shoulders, the outisde edges?

The anecdotal evidence from Prius owners posting here is that their Goodyear Integrity tires wear faster on the outer edges, especially at the recommended 35/33 psi. I've read many reports of this, but not a single report of an OEM Goodyear Integrity tire wearing out in the center first on a Prius, even at higher pressures. And many of these posters are inflating to 42/40 psi or other pressures well above Toyota's or your recommendation.

I certainly agree that usually the center of tires will wear faster and the shoulders slower as inflation pressures increase. It's a mighty big leap to say that in the second generation Prius inflating the soft sidewalled OEM tires above Toyota's recommended 35 psi front / 33 psi rear will cause these tires to wear faster in the center than on the shoulders. I like good theory, but can't find empirical evidence to support this. Perhaps it's an anomoly specific to these soft sidewalls and this car's suspension? Perhaps the recommended pressures were set in Japan where the Japanese market Priuses use Michelin tires. Perhaps the recommended pressures are lower than what would give the longest treadwear to sacrifice a little treadwear for better ride quality?

 

isnt it usually
front goes to the back
rear two crosses and go to the front

 

I've looked at a lot of Priuses in parking lots and talked to lots of owners along the way. Those that follow the recommended inflation always wear the edges badly.

However, even with higher inflation, It's clear to me that whichever tire is on the Left Front is wearing significantly faster than the others. I'd speculate two possible reasons. First, the only corner that is ALWAYS loaded is the Left Front (Driver). Second, modern driving means lots of sweeping right hand turns on freeway cloverleafs which wears the Left Front.

I've seen Priuses where the tires were never crossed and the Left Side tires are always significantly more worn.

My dealership does a cross every 10k as a matter of course, which seems to work out to keep the wear even.

I have 37K on the OEM tires right now, running a little higher pressure than standard, and with the occasional crossover I have even wear across each tire and even wear between all tires. The OEMs are not great, but they do wear predictably.

 

I rotate my tires in my garage at home. It's not that much work and I need the exercise anyhow. Fronts go straight back, the backs cross on their way forward. I did it at 10k and will do it again at 20k this weekend.

My tire wear is pretty even and I guess if I had new tires next to these ones, I'd find they're probably 1/2 gone I guess. They look all good still, and wearing evenly on all 4.

 

I rotate mine only when it results in better tread on the rear. It's safer to have better traction in the rear, to prevent fishtailing.

 

Correct! I still have service advisors recommending 2 new tires on the fronts. I recommend them being put on the rear as does Michelin, BF Goodrich and most tire manufacturers. Reason being the car is lighter in the rear and can slide from the rear and having the best tires on the rear prevents it from getting loose and coming around on you.
My proof

 

You want empirical evidence? Go down near the bottom of
http://techno-fandom.org/~hobbit/cars/tpms/ and see what happens
when you don't run the tires anywhere near their DESIGN PRESSURE.
.
_H*

 

<div class='quotetop'>QUOTE(richard schumacher @ Aug 2 2006, 09:35 AM) [snapback]296214[/snapback]</div>

Unless your car isn't front wheel drive, your tires should wear faster in the front. In that case, it seems that you would _never_ rotate your tires.

This is why Michelin's recommendation to always mount new tires in the back made limited sense to me. If you follow the rule of keeping the deeper tread in the rear, you give up rotating tires, at least between the front and rear. I do understand that it protects installers from liability, especially if this is the norm. Unanticipated oversteer (rear wheels lose traction in a turn, causing the vehicle to spin) can be much more dangerous than unanticipated understeer (front wheels lose traction in a turn, causing the car to plow straight ahead). Keeping the deeper tread in the rear will favor understeer over oversteer in snow and rain.

Still Michelin does not recommend always keeping the deeper tread in the rear. Yes, if the tread difference is large, when replacing two tires. No, if the difference in tread depth is small. Rotating the tires frequently keeps the difference small. Severe understeer isn't as safe as balanced handling. Besides, on clean dry roads, shallow tread provides better traction so deeper tread in the rear will favor oversteer on these generally safer road conditions.

Having driven MR2s for years, a heavy rear end does not limit oversteer except when using the throttle. Midengine cars are more liable to oversteer when braking. Remember the Corvair. The handling was excellent but different. Many drivers weren't in the habit of accelerating rather than braking on a fast turn to avoid spinnning.

 

[editted for clarity]
<div class='quotetop'>QUOTE(theorist @ Aug 2 2006, 12:12 PM) [snapback]296381[/snapback]</div>

Correct, I never rotate my tires, except:
- once, when I forgot to tell the shop not to do it during routine service, and
- when I buy new tires (two at a time). The new ones always go to the rear and the old rear tires/wheels are rotated to the front.

It's clearly safer to keep new tires at the rear. I've never noticed whatever variation in handling might be caused by shallower tread depth on front versus rear, and therefore it's not worth the trouble of periodic rotations merely to keep the tread depth uniform on all four wheels.

 

<div class='quotetop'>QUOTE(theorist @ Aug 2 2006, 12:12 PM) [snapback]296381[/snapback]</div>

No what they are saying, is rotate the tires. However, if you only buy 2 new tires where they should be placed...on the rear. They are basing this off the fact that there is a big difference in tread among the old and new tires. Many people take off the front tires and place on the rear and then mount on the front. So now you have a tire that has 10/32nds on the front and one with 4/32nds on the rear. Very bad idea and that's why they dont recommend it.

 

<div class='quotetop'>QUOTE(Blackfang @ Aug 2 2006, 02:17 PM) [snapback]296426[/snapback]</div>

<div class='quotetop'>QUOTE(theorist @ Aug 2 2006, 01:12 PM)</div>

It sounds like we agree. Michelin wants similiar tread depth all around, but if this is not possible put the deeper tread in back to limit oversteer in snow and rain.

I was arguing against _always_ keeping the rear tread deeper instead of trying to keep the tread depth uniform.

 

<div class='quotetop'>QUOTE(theorist @ Aug 2 2006, 02:32 PM) [snapback]296484[/snapback]</div>

<div class='quotetop'>QUOTE(richard schumacher @ Aug 2 2006, 01:13 PM) [snapback]296424[/snapback]</div>

This will, provide some info. Granted we saw this in person during our seminar when I was attending a seminar in 2004.

http://www.michelinman.com/care/tip6.html#5

The video link shows the benefit in wet wather and snow conditions