Strange tire wearing problem..what could it be???

What tire pressure do you run? Wear on the inside and outside areas would be a classic indicator of under-inflation.

 

If your tp is factory spec then IMO your tires are underinflated. Is your alignment in spec? Was an alignment done when the new tires were bought?

 

40 front/ 38 rear, or 42 front/ 40 rear are the pressures that many PC members use.

 

+1 for under-inflation.

What gauge are you using to check your tire pressure? Never trust the gauges on air supplies at garages, or built-in to the air compressors or pumps that you can buy. Always use a quality gauge, the accutire digital gauges were mentioned recently in another thread.

For the safe handling of your car, I would only use the range of tire pressures as printed on the label on the door jam.

<Rant>Unfortunately, many on PC will advocate higher pressures, but they have no qualifications to do so. Their only assurance is that they have tried it and their tires didn't go bang. What non of them have done is test whether over-inflated tires result in poorer handling during an emergency situation because they would need to:-
a) be highly skilled car designers.
b) conduct proper scientific experiments at a test facility and probably end up with a wrecked Prius and lots of measurement data.</Rant>

 

Wow. I guess the experience of hundreds of PC members over the last five years (since the tire wear issue was first noted on '04 models) doesn't count for much? You have every right not to use higher inflation pressures if you don't want to. But please don't try to scare the OP out of an easy fix that will solve his problem as it has for a great many others.

Anybody remember the root cause of the Ford Explorer/Firestone tire blowout problem? I do. I also remember the fix. Sometimes the highly skilled car designers don't get it right the first time they write the door jamb sticker. Fortunately the consequences are more benign in this case.

 

My advice is to properly inflate the tires within the range specified by Toyota. It is not clear that the OP has not been under-inflating the tires e.g. who knows maybe due to a faulty tire pressure gauge.

The advice given by many PC members is to over-inflate the tires often up to the sidewall max to maximise mpg, my recollection is that increased tire life isn't the primary reason for that advise. The max is presumably fine for the tire but I've yet to be convinced that PC members have tested the safety and stability of the car in extreme handling conditions (and I doubt they can do that with ancedotal evidence based on their normal driving).

I don't consider it to be scare mongering to point out common sense and to be cautious about a safety related issue. People should make up their own minds, given the information from both sides, here on PC too many IMHO promote just the over-inflation point of view.

 

Maybe that's a hint.

 

You are free to believe what you want. Maybe the author of the attached file has credentials more to your liking. Unless you are on the inside at the manufacturer or the tire vendor you don't know WHY a specific pressure was selected. Ford strong armed Firestone into agreeing to ridiculous low tp because the roll over rate was too high with higher pressures. Unless documentation can be provided I doubt Toyota & Goodyear recommended a tire pressure to maximize tire life and fuel economy.

BTW do you believe the Service Manager because he's a mechanic when he says you should change your oil every 3000 miles?

 

Thanks for the link to that police article. I just bought a new set of Michelin Hydro Edge with GreenX from The Tire Rack. I'll be using my digital pressure guage that I bought from them to set the pressure to the Mfg. recommended max of 44 psi. tonight. I just bought this sweet 2004 garaged model from the original owner (a neighbor). Interestingly, he told me that the "Prius eats up front tires, even if rotated". He stated this was because the front wheels are using the regenerative braking feature. Question: Has anyone else had problems with the front tires wearing prematurely, when the tires are rotated every 5K miles and properly inflated?
P.S. My first post to PCF!

 

The other thing to remember is to set the pressure when the car is cold, i.e. early in the morning and ideally in the garage. An article on TireRack.com suggests using 2psi more if the car's been outside in the shade and you're checking the pressure in the afternoon, 4psi more if you've driven it a bit, and 6psi more if you've driven extensively or over 45mph.

If you're setting the pressure to the placard when the tyres are already hot from driving, you could well be setting the pressure way too low.

 

So increasing the tire pressure beyond Ford's specificaton, affected the handling and caused more roll overs? How does that help advocate the use of higher tire pressures?

The linked article neglected to mention that police cars have many improvement including uprated suspension springs and shock absorbers. The police instructor holds a qualification in educating and does not appear to be qualified as an expert in the design of vehicle technology. Given the heavy modification of a police cruiser, I don't see how he can recommend that you do the same to an unmodified car?

 

Good point Timberwolf. The guy in the article seems to be simply saying. Higher pressure is better. However, there are more things to consider than what is important in a code 3 pursuit.

BTW I run 42/38, and the front tire outer edges still wear quicker than the middle. Also the front tires do wear much quicker than the back. Im sure that is due to a combination of FWD, along with the Regen braking. I dont drive very agressively either.

 

Underinflating them (actually to Ford's recommended pressure) resulted in many failed tires and many rollovers. It is unfortunate that Ford did not consider that in their design. Doesn't help that some tire manufacturers have problems with their rubber compound/manufacturing at times. I had a brand new Bridgestone come apart (burst) at Honda recommended pressure at moderate speeds...leading to a totalled Accord.

As it is there is a wealth of experience on PC that proves you wrong on the matter of tire inflation. The OEM Integrities seem to benefit considerably from inflating to around 40+ psi. From what I've seen here Toyota's placard pressures result in lower mileage, uneven wear, and therefore reduced performance. Tires operating at lower pressures have more heat build up which is not good for the tire. In otherwords what you recommend is generally LESS SAFE than the alternative you are ranting about.

The max pressure on the sidewall is a safe pressure for the tire. It has considerable built in safety factor, actually several factors of derating (as another poster with tire production experience pointed out in another thread.) That's pretty normal for design.

While I was skeptical of higher pressures at first, I've since come around.

 

Thanks Shawn, for explaining the Ford under-inflation - that makes much more sense now.

Maybe I haven't been clear, I don't dispute either improvement in tire wear or better mpg with the higher psi. What concerns me is how it may effect the handling and how the advice between the motor industry, motoring organisations which say to use the correct tire pressure, and what PC and hypermilers recommend.

 

Side wall burst pressure is twice the max cold inflation pressure. The low pressure that dealers insist on is to prevent rattles and make a nice cushy ride. I inflate most of mine to the max cold. Past that point you are on your own. Tires that have 50-60 PSI could be a problem on a bumpy road with traction. Thats why I am stuck at 44-47 PSI at this time.

Thanks man,

 

BTW/ I ran 2 of my Hondas at 51PSI for years folks and the dealer could not believe how little the tires were worn. He said I would wear out the middle and it never happened. In fact I have never had the middle wear out first on my hybrids. On my 5th BTW and the way radials are designed that should not be a problem unless the suspension or alignment is hosed or a bad design. IMHO

 

Your neighbor is misinformed. Regen braking doesn't affect the tires but does reduce wear on the brakes. Front tires will be eaten if the alignment is out of spec.