Toyo Proxes A20 P215/45R17 87V tires

Just checked the model years, and it appears there have been serious problems with Toyos on the 2010, 2011 and 2012 model years, so it is hard to suggest this is a "batch" problem with the tires.

I'd like to know if tire pressure has any correlation. I'm quite surprised mine have lasted so long, and I wonder if it isn't because I assiduously check the pressure and keep it rather high (never above the cold temp max).

 

What do you run? I am running 38/37 and check them weekly. Bad country roads I commute on prevent me from running any higher without everything rattle to the point of being super annoying.

 

It depends on the circumstances, but I run 48/47 if I have clear roads and no additional weight. At other times I'll drop to 44/43. I have tried higher pressures, but the ride became ridiculous, and I didn't see the benefit. At lower pressures, the car doesn't seem to handle very well, and I do notice a drop in MPGs.

 

Mine are 17" and I run 38# front and 34# rear, not for the mileage, but if I go higher, the ride quality from the lower profile type gets much worse. I'm at 23K miles on these poor excuses for a tire model, and the sooner they wear out, the better. One was replaced at 2K miles (post on previous page) and another got punctured from a stick in the road. Toyo never again.

 

I wonder if you should scale up the pressure, instead of keeping the 1PSI F/R offset. I.e. 44/42 would be approximately a ratio of 1.32X of the specified 33/32. Would that be more appropriate than 44/43?

 

Thanks for the suggestion. For some reason, I recall reviewing this three years ago and deciding the small offset was appropriate for what I was planning. Of course, I can't recall right now exactly why I made this decision.

 

I bumped the pressure up to 39/38, and oddly it rode better over the bigger bumps. I no longer get that "hollow" trump, when hitting the bump. I am going to try 44/42 for a week, in light of this discovery, and the Toyo sidewall failures.

From what I have read, higher pressures reduce the odds of a sidewall failure, due to less flexing. Maybe the A20 sidewalls are weak by design from the get-go to save weight.

 

I am happy to see that Discount Tire is now carrying the Michelin Primacy MXM4 in the Five size locally, for $10 more than Tire Rack (mounting included and no shipping, might be cheaper actually). I know what my replacement tires are going to be down the road.

 

Interesting Posts. I just bought a Prius Five 2012 and I immediately, without reading up on Toyo Tires, decided to purchase Michelin Primacy MXM4. However, these Toyo's retail for anywhere between 215-275. So I am leaning toward getting as much out of them as possible and then purchase the Michelin's.

 

Interesting Posts. I just bought a Prius Five 2012 and I immediately, without reading up on Toyo Tires, decided to purchase Michelin Primacy MXM4. However, these Toyo's retail for anywhere between 215-275. So I am leaning toward getting as much out of them as possible and then purchase the Michelin's.

Read more: http://priuschat.com/threads/toyo-proxes-a20-p215-45r17-87v-tires.100144/#ixzz27VcKMwUq

 

Additionally, the OE Toyo Proxes A20 offer better fuel economy so I would keep them as long as you can before upgrading to the MXM4 despite the later being a superior tire in every respect other than fuel economy.

 

I am posting a link here, in attempt to document all the Toyo Proxes A20 sidewall failures in one thread.
Tire blowout. Am I liable to pay for it plus damages? | PriusChat

Please post links if you have other reports of this tire failure! It is getting scary. Not because it is Halloween.

 

Well, I have been enjoying my prius (new to me.. 2011 Prius 5 w/ 15K mi. and proxes A20's) but noticed the tire pressure at 30psi... it is getting cold (Apex NC) so I was looking to fill them up close to the recommended max... glad I found this thread.. will go 44/42 or 48/46 ... and will check the impact on MPG...getting 47.5 at the moment ... no apparent structure issues with the A20s at the moment.

 

Given the sensitive nature of the A20s I would probably run them no higher than 42/40 or so. Even 38psi would probably be fine for mpg and comfort. They are a rather loud and rough riding tire.

 

Yep these are some rough riding, and loud tires. I keep mine inflated at 44/42PSI, to help reduce sidewall flex and blowouts. I have to modify my commute. Now, instead of going on 2 land country roads with bad pavement, I use city roads with better surface. Which make my commute 2 miles longer, and the indicated MPG down from 65 - 60 (traffic lights).
I am rationalizing this loss, by not having to replace the Toyo's before they wear out. $750 buys a lot of gas. Also, I am also afraid of the rough drives may rattle something loose inside of the car.
BTW the sidewall of the Toyo is 1 ply. Most passenger tires I checked, are 2 plies or more. Maybe the reduced the sidewall ply count to help with MPG, but it is making it more blowout prone.
EDIT: Just went out to the garage to did my weekly pressure check. The sidewall is 2 plies polyester. Thread is 2 steel, 1 polyester, 1 nylon. I must have read it wrong last time. Sorry about spreading misinformation.

 

Oh, I probably have mentioned this somewhere else, another problem with these tires, is they tend to lose 1 PSI every 2 weeks or so. I check them weekly in the garage at room temp, and I have a room temp thermometer for the garage for temperture compensation, so I know the loss is not imaginary. This is more than double the rate of loss for all the other cars have have driven.
Word of caution, with the reported blow outs, and the apparent high rate of air loss, check them weekly. Do not rely on the TPMS, which does not go off until one of them is 25% below set spec. A lot of damage to the sidewall could be done during the time it goes from 100% to 75%.

 

The A20s are a load rating 87 which is lower than the OE 15s but the same as most aftermarket tires of the same size. The 205/50/17 is a load index 93 which is higher than the OE 15".

 

Is load rating related to the # of plies used in the sidewall? More load requires more plies? One would think...

 

It used to be when simply adding more plies made the tire stronger so it could handle more load. With modern tire tire design and materials they stopped using number of plies as a rating and they moved to actual load rating. For example, my EP422 205/50/17 is rated 93V XL but it only has 1 sidewall ply and 4 tread plies. What does your tire read?

Plies:
Tread = 1 polyester + 2 steel + 1 nylon
Sidewall = 1 polyester

 

Just went out to the garage to did my weekly pressure check. The sidewall is 2 plies polyester. Thread is 2 steel, 1 polyester, 1 nylon. I must have read it wrong last time. Sorry about spreading misinformation.
Edited my post above.
Read more: http://priuschat.com/threads/toyo-proxes-a20-p215-45r17-87v-tires.100144/page-2#ixzz2BBPmBCiN