max oem tire pressure

[diamondlarry]

Driving Under Pressure: Editorial & Features at Officer.com

I have ran at no less than 60 psi since day one and have over 15K on the odometer. The last 5K or more at significantly higher than 60 psi. NO uneven wear and NO handling problems. Stock Integrity's.

[Rich96c4ce]

"Remember that the Toyota recommended pressure was for a specific brand of tire, the one that it is sold with, and not for other tires. The door pressure is specific to one make and model and really has application for warranty coverage. Once the tire brand and model is changed, Toyota warranty coverage is done. You are the owner of the car and should manage it based upon your best understanding of what works."

The statements in orange are not true. The tire placard is for all tires of the size and load range specified. That is because of Federal Motor Vehicle Safety Standards for tires and wheels. It assures that the tires specified for the vehicle are pressurized such that they can withstand the load that they are required to support. In the case of a Prius, the pressures are what Toyota Inc. have determined is necessary for the vehicle with the tires of the size specified by Toyota on the placard will comply with the applicable Federal Motor Vehicle Safety Standards.

You may wish to read the applicable Federdal Motor Vehicle Safety Standards as follows:
http://a257.g.akamaitech.net/7/257/2...cfr571.110.pdf and http://a257.g.akamaitech.net/7/257/2...cfr571.109.pdf

[bwilson4web]

Originally Posted by Rich96c4ce

"Remember that the Toyota recommended pressure was for a . . ., the one that it is sold with, and not for other tires. The door pressure is specific to . . . and really has application for warranty coverage. . . . , Toyota warranty coverage is done. You are the owner of the car and should manage it based upon your best understanding of what works."

The statements in orange are not true. . . .

Hopefully we can now agree on the rest.

For those who feel most comfortable with following the manufacturer's recommendations, they are well documented. Certainly, you should never fall below the recommended minimum pressure as this can cause loss of control, sudden failure, and premature wear. I've had a blow-out in another vehicle and in hindsight, it was probably due to low tire pressure.

I have not found going over the recommended pressure to cause any measurable or observable problems. Tire wear of my radial tires is consistent across the thread. In fact, it has led to great cornering and precise handling. Though the ride may seem a little harsher, modest driving speeds pretty well mitigates that problem (aka., slow down!) My mileage is good too.

Bob Wilson

[xsmatt81]

run 43/41 here with 44.8 mpg right now. I have not tried any other pressures, sometimes I get lazy though and let them go down. I bought a Husky oil-less compressor during xmas. And it is great!! Very portable, 130maxpsi. Has attachments aswell, I use it at 40 psi to clean my computers mostly, and light dusting. It can also be used at higher pressures to dry one's car after a wash. HAving a black car makes you very anal about swirls!

link to husky air blower

Black Friday Ads 2007 - Husky 1.5 gal Air Scout Compressor at Home Depot

Oh in regards to regular TP. I suggest checking the lug's with a torque wrench everytime. I put aire in twice a month. I think twice a month for lug torque is more then enough, again sometimes lazy and don't always check=D

[Rich96c4ce]

Originally Posted by bwilson4web

Hopefully we can now agree on the rest.....Bob Wilson

You bet!

[Genoz World]

when i ran the standard 32-35 psi's in my previous cars, the vehicles felt like slush buckets, handling was bad from sidewall rollover, and the sides wore out quickly.

almost all my cars had tire pressures of 38/36. now to clarify, i measured the psi's cold.

when i read on this site to run 42/40, i was a bit surprised as i heard that the goodyear integry's are NOT good tires, but i tried it and so far, so good. i only have 1,400+ miles on my new prius, but no problems.

i made a post before, but nobody answered me as i really dont know why quite a few people here consider the integry's as "NOT A GOOD TIRE"......

WHY IS IT THAT SOME CONSIDER IT A BAD TIRE? i've had no problems with them......?????

[bwilson4web]

Originally Posted by Genoz World

. . . WHY IS IT THAT SOME CONSIDER IT A BAD TIRE? . . .

The others will have to answer that one because my used Prius came with Mastercraft (Sears) tires and I've already replaced them. But I can offer a couple of hypothesis:

• Let the dealer set the tire pressure - too low and they wore out quickly and handled like squishy balls
• Prius alignment - a thing of wonder and horror, only the front wheel toe is easy to adjust and it is so easy to 'slide' if the rear wheels or front camber are off

From my point of view, there are better tires available:

• Michelin X Radial (79) weak: none
• Michelin Agility Touring (62) weak: snow ice life
• Michelin Harmony (61) weak: ice
• Toyo 800 Ultra (51) weak: braking
• Sumitomo HTR T4 (44) weak: ice and wet

Living in North Alabama where "snow days" are holidays, I have Sumitomo HTR T4s running at 51 psi. I'm not worried about wet braking because of the unusual paving practices that turn every street into a giant "slip and slide" whenever it gets wet (I should stop so the goober behind me can run into me??) I'm getting good mileage and the tires are wearing well, especially after I fixed the rear wheel alignment. Consumer Reports was my guide.



Now if I lived further north in an area that paves streets with something other than "slip 'n slide" paving, I would choose a different tire. For example, Washington DC where they have a lot of diplomatic accident-mobiles, I would go for the top of the line Michelin X Radial.

GOOD LUCK!
Bob Wilson

[tharvey]

Hummm a lot of varied comments, and a real lot of good points.

I have just retired from 31 years of Policing and when I got bored they kept sending me for different courses. As I think with the right side of my brain, I am really good at math, and poor at english.

Needless to say when I kept going for traffic investigation courses, I did well and thus the further I went into traffic investigation to the point where I am qualified as an expert witness in traffic investigation, and I have been a qualified traffic analyist since 1991.

I agree with the comment that the manafacturer did extensive testing, and if they could get better mileage out of higher psi then they would, even if it meant a trade off in tire wear.

This does present a problem as under inflation will cause a blow out of the tire, and over inflation will cause uneven tread wear and poor tire adhesion with the road.

I guess the point of this is to get the entire tire tread on the ground the majority of the time. If we under inflate (which I do not think is the case here) we will get excessive tread wear on the inner and outer sides of the tire.

This should not be confused with the wear of tires we see on the front tires which cause wear by the fact that they are turning left and right all the time.

If we over inflate then we will wear the center tread down and this is often confused with what we see on the rear tires which get minimal wear and always go to an over inflation state when braking, as motion is transferred from the rear, to the front of a vehicle during any braking action.

I have done numerous research on this attempting to get an answer for myself, and I have to agree with the comments that engineers have spent numerous hours on making this a safe vehicle.

I do not use the word comfortable as it is quite easy to adjust spring and shock rate to compensate with rough riding tires.

The markings on the drivers door is for a size, and weight rating, for a specific sized tire.

This is very important as one major wholesaler, put different tires on a vehicle, at the request of the owner and when his 16 year old daughter rolled over the brand new vehicle, he being a lawyer naturally blamed the store and sucessfully won the multi million dollar lawsuit.

The jury concluded that the maker of the vehicle new, and specified the tire size, and psi, for the vehicle in which they were manfacturing, and thus they new best.

I would have to agree, we surely would not self medicate or do anything else contrary to what our doctor tell us, however we often see abuse of this by others who know better.

Now to attempt to resolve this dispute, there are an extremely high amount of variables in this matter, and if we look at what the professionals do, we can find a possible solution for the correct air pressure for a given size, weight, and type of vehicle.

To do this you will need to buy beg or steal opps I mean borrow an accurate laser thermometer which can read variances in temperature within .1 of a degree.

Start with a vehicle which has been sitting overnight and set the air pressure to the specified door pressure.

Now take the vehicle for a drive on the highway of at least 3-5 miles, to heat up the tires and then safely pull over and take 3 reading off of each tire.

The readings will be the inside tread of the tire the center tread and the outside tread of each tire.

If the center tread temperature is higher then the outside it means you are riding on the center portion of the treads and thus the tire is over inflated.

However if your temperature readings are higher on the inner and outer treads as compared to the center of the tread then the tires are under inflated and your tires need more air.

We then add or subtract air as needed in order to have an even temperature across the entire tread of each tire.

I generally measure all 4 tires and average the left and right sides together and thus I keep the left and right psi the same however I vary the front and rear.

I use to have access to an expensive $3,000 laser gauge, however I have purchased a fluke thermometer for under $100 which will work just as well.

This testing will take about a week for each set of 4 tires and greatly varies with summer and winter, however I have noted on the performance vehicle, which I did for myself the door sticker requires 30f/32r and on my winter ice radials I use 34f/36r and on my summer tires I use 30f/34r which is around 5% off of the specified door sticker.

I guess it will come down to personal preferences unless you are involved in a major accident where they call a traffic analyist to the scene and he happens to check your tire pressure.

In Canada all major investigations will get a full mechanical inspection by a mechanic and traffic analyist and I will guarantee you he will check all 4 of your tires for the pressure at the begining of his examination.

If he finds 51-49 pounds psi on a vehicle specified for 35-33 psi this will leave interpetation for "someone" whom might feel the over inflation of the tire was a contributing cause for the accident, due to lack of tire patch to road contact area.

This is not a guarantee, just a possability, with insurance companies looking for way to keep their profit margins, they are hiring engineers, traffic reconstructionists and ex traffic analyists to further investigate their insured vehicles.

Only my .02 cents worth, however if and when I get my touring with level 6 package I will have lots of time to verify this.

[Genoz World]

BOB WILSON,

thanks. i've seen you around and the posts that you make are informative and accurate.

the question i have for YOU is that on the list that you provided, (cool chart, by the way) where do the GOODYEAR INTEGRETY'S rate?

cheers.

[xsmatt81]

Genoz check this link out.

Goodyear Integrity Tire Reviews & Ratings - Rate or Review a Tire

Imo they are adequate tires to start with, plan to replace mine probably after 25000 miles with something better from toyo or michelin.

check out this video from youtube they test few cars in handling, including the prius. It scored better than the competion compacts on stock tires.

YouTube - Prius-Kenari-Smart