The car manufacturer's recommended air pressure is printed on a plate or sticker on the car and it's usually somewhere around 29 to 32 PSI. Why do the tire and oil-change places put in so much more air?
2007-01-12 05:56:20 · 13 answers · asked by Bob Little 4 in Cars & Transportation ➔ Maintenance & Repairs
I'm getting some interesting answers. As for those who say I'm just going to the wrong places, hey...I'm doing the best I can. Every place I go (except the car dealer) does this...even the place that sells me the tires.
2007-01-12 12:38:08 · update #1
Many vehicles have accidents from under inflated tires. If the service establishment didn't put enough air in your tires and you had an accident due to their fault, then they would be liable. To cover their own butts, they put the maximum pressure in the tire. If you choose to change that pressure, then they are not responsible for any damages, they think! Some times it is just plain stupidity. If you read the pressure on the side of the tire you will see they put in the tire what the maximum is printed on the tire. They ride just a might bumpy, don't they?
Glad to help you, Good Luck!!!
2007-01-12 06:06:34 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Wow, some truly appallingly bad answers up there.
First off, you were absolutely correct and you can completely ignore the Mark who posted that you should never follow the vehicle manufacturers tire inflation pressures. Everything he posted is exactly the opposite of what you should do.
Manufacters have dozens of guys with walls full of engineering degrees spend months of testing to determine what the optimum tire pressures are for that particular vehicle. They then go to the bother of sticking that information on a metal plate which is then permanently attached to your car.
Why wouldn't you follow that?
The inflation pressure that is molded into the sidewall of the tire is not a recommended tire pressure for any vehicle, particularly since that particular tire might have a dozen or more different vehicle applications it fits all of which have different inflation requirements. Rather the information on the sidewall merely indicates the maximum pressure that particular tire should be inflated too and how much weight it can carry at that pressure. That's it.
Follow the vehicle manufacturers recommendation for tire inflation front and rear and always adjust pressures when the tires are cold (have not been driven on recently for more than a brief period).
As for why quick-lube shops over-inflate tires... I'm sure not all of them do but I know from experience that when I was stupid enough to use such facilities I don't recall them EVER getting my pressures right. Part of that is a lack of training - these are not mechanics you are dealing with, and certainly not tire experts. Some of it is just plain ignorance - which goes back to the training thing. For some, maybe its just easier to put 35 psi in everything. Back in the old days everybody used to just put 35 psi in every tire and they never had to think about it.
Now that lawyers have discovered they can make a nice living off tire liability lawsuits there has been a big shift in the industry. Most reputable shops and tire dealers will only inflate to factory specs and will only install replacement tires that exactly match the factory OE spec - no more putting cheap, entry-level S-rated tires on a V6 Accord that takes a V-rated tire for example. It takes a while for that to trickle down to places like quick-lube shops where tires are not a major part of their business.
But there again is another argument for not using quick-lube places. They don't have the expertise and experience nor do they take the time to really maintain your vehicle properly.
2007-01-12 10:07:33 · answer #2 · answered by Naughtums 7 · 1⤊ 0⤋
The recommended pressure is when the tire is cold. Heat makes the air expand and pressure goes up. Highway driving makes your wheels get warm. Braking can easily get the wheels too hot to touch. Pressure depends on temperature.
The car's recommended pressures are for the original tires. Several factors are used in determining the recommended pressure. Braking distance and ride comfort are a couple things looked at. If your goal is cornering ability, then you'll run at a different pressure. If your goal is fuel economy, you'll set the pressure to the maximum rating on the tire. If you want maximum tread life, you have to drive gently and rotate the tires often.
2007-01-12 06:58:43 · answer #3 · answered by vrrJT3 6 · 1⤊ 0⤋
they are not train techs so they look at the sidewall of the tire. Sidewall says max inflation 44 psi so Johny puts 44 psi in tire.They are unaware of the sticker on the door for the manufactures air pressure
2007-01-12 06:01:20 · answer #4 · answered by Rudedude 4 · 1⤊ 0⤋
well obviously you are going to the wrong places to have the tires checked. Any competent oil change shop or tire store should know that the recommended tire pressure is either on the drivers door jamb or inside the trunk lid or somewhere like that. If they are not checking for that then ask them why and stop going there and find someplace that does it right.
2007-01-12 12:08:43 · answer #5 · answered by rwings8215 5 · 1⤊ 0⤋
because the people that work their do not make alot of money so they dont care u pay 4 what u get all they are doing is putting on a show 4 u because they dont think u no any better i would complain because 2 much air could cause your tire 2 blow and may cause and wreck also the tires will not wear right
2007-01-12 06:08:50 · answer #6 · answered by Anonymous · 1⤊ 0⤋
The good ones don't. The good ones read the specifications on your vehicle, and meet them. It is common to put more in the spare though since you probably don't check it as often, and it can lose air. Nothing worse than a flat tire and a flat spare tire too.
2007-01-12 06:01:14 · answer #7 · answered by oklatom 7 · 1⤊ 0⤋
NEVER follow manufacturers plate those are for stock tires follow tires sidewall keep press inbetween min. pressure and max and same pressure on all tires for even wear
2007-01-12 06:10:08 · answer #8 · answered by mark 2 · 1⤊ 1⤋
most of them are dumb and f__k your s__t up they strip out the threads on your O.P. and put the plugs in way to tight all you have to do is get it snug and then give it a half turn and most oil change places the employees are quite young and aren't really sure what they are doing personally i just change my own
2007-01-12 06:08:54 · answer #9 · answered by Anonymous · 1⤊ 0⤋
Better gas mileage
2007-01-12 05:59:17 · answer #10 · answered by (A) 7 · 1⤊ 0⤋