Just Rotated the Tires

[TonyPSchaefer]

As an addendum to this thread: http://priuschat.com/forums/prius-ma...c-anomaly.html and this one: http://priuschat.com/forums/prius-ma...tire-wear.html

I rotated my tires this morning: straight front-to-back, no side-to-side switching. Then I ran some errands. Here are some things I noticed. Someone tell me if this is normal:

1. The first thing I noticed is that the noise I reported in the "Aerodynamic" thread is now in the front confirming that it was the tire(s) making the noise.
2. Then I noticed that the noise of the tires is likened to the sound of over-sized Jeep tires for mud.
3. My coasting and gliding ability seemed greatly reduced.
4. My tank average MPG dropped 1.9mpg.

Keep in mind that this is the first time the tires have been rotated. They are 47,500 miles old.

[bwilson4web]

Can you get and report the current tire alignment?

Could you measure each tread depth of each tire and report them here?

Bob Wilson

[TonyPSchaefer]

tire alignment: not without spending money so don't hold your breath.

Tread depth: sure, why not.
Here's the results. These are the standard Integrity. There are four tread "stripes" separated by three ridges. Measurements are all presented as Outside - Middle - Inside

• Back Left: 3/32 - 5/32 - 4/32
• Front Left: 5/32 - 7/32 - 12/32
• Front Right: 4/32 - 5/32 - 4/32
• Back Right: 4/32 - 5/32 - 4/32

Keep in mind that until this morning the backs were the fronts and vice versa.

Looking at those measurement, that front left sure seems like the odd duck.

[Patrick Wong]

Originally Posted by TonyPSchaefer

• Front Left: 5/32 - 7/32 - 12/32

Keep in mind that until this morning the backs were the fronts and vice versa.

Yes, and since the front left tire came from the rear left position, it is likely that the wheel alignment at the rear left position is off. My guess is that the front left tire is the source of the noise that you reported.

Was the car ever in an accident? Rear wheel alignment will require shims to adjust, and this will have to be done by an alignment shop since Toyota's service policy is that rear wheel alignment is not possible, the only remedy is to install new suspension parts.

Looks like you will definitely need new tires before winter.

I also don't understand how the tread wear on the right-side tires can be so even if in fact the tires had never been rotated. I would have expected the tire that had been on the front to be much more worn compared to the tire that had been on the rear.

[TonyPSchaefer]

Originally Posted by Patrick Wong

I also don't understand how the tread wear on the right-side tires can be so even if in fact the tires had never been rotated. I would have expected the tire that had been on the front to be much more worn compared to the tire that had been on the rear.

I wrote the numbers without referencing any other measurements and they were all done the exact same way. It is odd that they came out the same, huh?

Priapus has never been in an accident.

I'm hoping the new tires and realignment will make it all better.

[bwilson4web]

Originally Posted by TonyPSchaefer

...
Tread depth: sure, why not.
Here's the results. These are the standard Integrity. There are four tread "stripes" separated by three ridges. Measurements are all presented as Outside - Middle - Inside

• Back Left: 3/32 - 5/32 - 4/32
• Front Left: 5/32 - 7/32 - 12/32
• Front Right: 4/32 - 5/32 - 4/32
• Back Right: 4/32 - 5/32 - 4/32

...

The now 'Front Left' is certainly the "odd man out." The data suggests it has suffered from some form of positive camber, instead of the tops being inward, they were leaning outward, when it was on the 'Back Left' wheel. The other numbers are "OK". You have almost no wear on the "12/32" tread and that is probably the 'noise' ... as Patrick called it.

What pressure have you been running the tires?

Bob Wilson

[TonyPSchaefer]

Originally Posted by bwilson4web

What pressure have you been running the tires?

Aug. 2004 - Aug. 2006: 35f/33r
Aug. 2006 - Aug. 2007: 42f/40r
Aug. 2007 - Present: 52r/50r

[qbee42]

Do you have a bad belt in one of the tires? That can make the Jeep grave-digger tire sound.

Tom

[TonyPSchaefer]

Bad belt?
How would I know?

[bwilson4web]

Originally Posted by TonyPSchaefer

Aug. 2004 - Aug. 2006: 35f/33r
Aug. 2006 - Aug. 2007: 42f/40r
Aug. 2007 - Present: 52r/50r

Ok, that makes a lot more sense. Two years of 'lightly under inflated'; one year of pretty close; and one year of about right. The edge wear looked consistently thin except for "the odd man out."

If I remember my tire specs correctly, you are approaching the point of time to get new tires. When you do, I would recommend getting the wheel alignment checked and a listing. Post it here and we can offer some suggestions on how to fix that "odd man out" problem. The time for perfect alignment is when the tires are new!

Personally, I've been reasonably happy with the Firestone lifetime alignment service. Apparently it is not tied to the tire "lifetime" but the vehicle "lifetime." So I rotate the tires each year and get another measurement. I think they've done 6-8 already and will do another one in a day or so. This has been a great buy!

Bob Wilson