Wildfire3210

Here is the situation:

I was deemed inexperienced, due to my young age and disclosing that I recently purchased my car, by a local mechanic which insisted I left in the 50psi he put in my tires. Tell me about the advantages / disadvantages of this?! I've read tirerack.com details, but I wanted to see what you guys had to say.

He backed up his action by saying the "max pressure" on the tires side walls is displayed as 51psi and he has always recommended to put that amount in the tires. Saying the extra air pressure will allow for the middle of the tire tread to wear more evenly as opposed to the chamfered edges of the treads when there is less pressure in the tires. Also that if I hit a pot hole with less tire pressure I can compress the small side walls and scuff a wheel. As well as improving MPG on the highways.

The door jam and the manual is what I was basing my previous tire's pressures on of 29 in the front and 33 in the back I believe. And then +5 psi due to speeds over 100mph...so I was sitting at around 33 in the front and 37 in the backs. The tires are Michelin Pilot Radial X 245/40 R17 in the front and 225/45 R17 in the back - same size as stocks. I am concerned with possibly blowing out a tire once they get up to temperature and hitting a pot hole or something else occurs to exceed the max pressure recommended. The car also handles differently and has a MUCH stiffer feel.

I am itching to let the air out and put them back to what I had them before.

Logical, Technical thoughts and comments are appreciated and welcomed


Thanks!

Chaz00Blue

You should always run the tire pressures at the correct operating pressures. He is full of it. Running it at the max pressure will cause the tires to wear out sooner.

C300Sport

I think your mechanic is a little touched in the head.
You should run the recommended pressure for a good mix of comfort, handling and fuel economy. I tend to add a couple PSI which may help a touch with fuel economy and slightly improve handling. Of course a couple PSI may slightly reduce ride comfort at the same time. It may be a personal choice but I wouldn't vary more than 5 PSI from recommended.
If you run 50 PSI, the middle of your tread will wear out prematurely as the tires center is bulging out.

peabers

Isn't there also the issue of warm tyres vs. cold tyres. The spec in the vehicle's manual provides for the recommended cold weather pressure. The spec on the tyre is the maximum PSI tolerated by the tyre in any condition. So if you cold weather pressure was set to 50 psi, then when the tyre warms up, the psi increases, and you end up exceeding the manufacturers maximum threshold?

amdeutsch

Let me guess; he also told you to come in and change your oil every 3000 miles.

tanktube67

Simple if you running the stock tires fallow the decal on the door jam.

eminnet

I am afraid that you already compromised your rubbers.
Inflating them to the maximum permissible pressure is insane.
They may developed bulges. After setting the correct pressure check again balance and also visual checking will do no harm.

AkaSigFreak

He said you compromised your rubbers
That's funny

micropower99

The tech that said that must either be retarded or deliberately trying to get you to f*ck up your tires. Not only will it mess up your tires but its a huge hazard in general. Your riding on fu*cking balloons! lol

len56

someone is busy deflating :P

Krytech

Well I think we can all finally agree on something, 50psi is WAY over the top. Always use the recommended tire pressure from the AUTO manufacturer, and do NOT go by what is written on the tire, that's only there for reference.

C300Sport

lol...true, it is one of the very few times everyone has agreed on something.

alexlev

Did he recommend pouring some of this into your gas tank to increase HP? . .

axhoaxho

Like everyone says, don't do it.

Especially, if we put 50psi in cool temperature, the psi will become much higer when the tire is running hot during a warm day -- which can be dangerously over the maximum pressure.

Regards,

Glyn M Ruck

Your mechanic is a congenital masturbating moron. Reduce tyre pressures to normal or not only will you shake your teeth out but you will wear the center tread on your tyres.

RLE

The only local mechanic who should have his hands on your car is at the dealer. And since you are not driving over 100mph, forget those numbers. Use the pressures shown on the gas flap.

You mention that you are young and although I don't know what you mean by that, I do know that a younger inexperienced driver should not be driving that fast until you get some experience under your belt.

The fatal accident rate of young males is the highest of all drivers.

spoolIT85

best post i've seen all day

CrAZyVeGAsBoY

+1 cant go wrong with this

Onizuka

Isn't the recommended psi 38 or something like that?
I remember hearing some horror stories such as having a car flipped over from some bumps because of having too much PSI in the tires..:|