Maintenance (Oil Change) Every 5000?

Maybe more going on there. Typically I think you'd just see the tread depth going down faster on the fronts (due to more loading, cornering, etc), and the insides wearing faster on the rears (due to neg camber).

 

I've had three different tire shops tell me they see cupping on Prius rear tires all the time. Alignment was good (only 0.2 out). They guessed it was from battery weight.

 

Just follow the manual, change the oil every year or 10k miles.

 

Some car tires can't be rotated because or running different size wheels front and rear and I never heard flat spots mentioned on them.

I'm not saying it didn't happen, like Mendel said, maybe something else is going on.

 

Could be something, but it's verified not to be alignment or suspension. Not sure what else might be a factor in cupping.

 

Under-inflation is a common cause of cupping.

Sometimes it's the design of the suspension; blaming it on the "battery weight" might be a different way of saying that.

This might be why they seem so adamant about having them rotated every 5000 miles.

 

Could one of the flat spot accusers tell me how they got flat spots for n their tires? And, how rotating tires helps resolve flat spots?

Cupping is a rebound problem, either too fast or too slow. Chamfered down on the leading edge is too slow. You get a debris field on the trailing edge w too slow but only really seen in racing. I have much race history and gets shocks built and tuned on shock Dyno before installation. This is a whole nother topic. Trust me, too much detail for me to talk here. I give seminars on this....

 

Cupping can be caused by several things. The most common being low air pressure.

Rotating is good because the design of the suspension might cause some slight abnormal wear on the tires that can't be "fixed" reasonably, and the rotation kind of covers it up.

 

It's interesting, that Toyota recommends keeping wheels/tires on one side, just rotating straight back or forward. Honda always said straight back and cross to front, as long as I can remember. Unless they were directional.

I kinda like Toyota's directive, if only because two of the rims accumulate less road rash.

 

Really ?? Can you document that somewhere ?
Pretty sure that neither of my C's nor the previous Corolla (badged Chevy Prism) had that recommendation.
(But my owners manual isn't here to look into at the moment.)

 

Screen grab from US 2014 Prius c Owner's Manual I downloaded, page 384:



My 2010 says the same. That last sentence is one reason I use the same pressure on all. Don't think it really matters though.

 

Amazing.

I wonder if that is because the OEM tires have a directional tread pattern ??

I will check my manual when/if I can remember.

 

I think it's rare (if ever) the OEM are directional. No mention of directional either, just a blanket statement. I've gone along with it, but am a little curious myself, why they say this

 

I thought a four tire rotation was always just front to back unless you have a spare tire then there is another procedure and is always listed in the owners manual. I have never used the five tire rotation myself.

Directional tires are common on performance cars and maybe off road type use and common on some big trucks.

 

Honda's always said straight back and cross to front. Not sure about others.


(2010 Pilot Owner's Manual, one I happened to have.)

 

1. Install new tires on Prius. Drive 10,000 - 15,000 miles without rotating them. Check them weekly and keep them at 38 - 40 psi. Take note of the growing "wump wump" sound at certain speeds. It's happened to two completely different Prius models in my household. Lesson learned.

2. Rotating doesn't resolve flat spots once they're there. It can help prevent them because the rebound spot is going to change when the tire is mounted on a different wheel, and most likely a different orientation.

 

What caused flat spots and how do you know they're flat spots?

 

It has to be something peculiar to the Prius suspension since the dealer and the tire shop both reported that the suspension is fine. The alignment was also fine.

How do I know they're flat spots? You can see them with your eye just looking at the tire.

 

Overnight thoughts:

I suspect that they found little to no real advantage to an X pattern rotation.....AND it is much quicker and easier just to do "front to back".
Of course what they charge for the service does NOT reflect the time savings of doing it that way.

 

Are those all the same brand and model of tires ?

I once had a set of Firestone tires that wore the SECOND from the outside rib much faster than the rest......on all 4 of the tires.
Manufacturing defect having to do with the belt placement.