exact air pressure ratio in tyres

[wilsoncruise286]

How much air should i put in a normail car, i recently purchased a new air pressure machine to put air to tires by myself but i am unable to use it becuase i dont know the exact air pressure ratio. It will be a great help....

[Roux]

have an owners manual that tells you what pressure to put in there. Or look on the back of the doors for a label.

You could also go to a forum dedicated to the brand of car you own and ask there

[LenFC11]

most road tires have a max air pressure right on them. i'd go with that

[stephen wilson]

The maximum pressure is rarely recommended. Steve has it right, look for a sticker on the door, door sill, or possibly in the glovebox. ( and of course the owners manual )

[TedV]

the devils advocate in me says, remember the Ford Explorer- Firestone fiasco? Ford said run 28 lbs in a car tire under a truck chassis.

I wonder why they blew up and killed people?

Usually the factory recommended pressures, up to 8 or 10 lbs over recommended pressures seem to give good results depending on the use. Generally not to exceed the max pressure on the tire sidewall, unless you have to use a car tire in a pinch as a trailer tire to get home then 50 to 70 PSi works better than the 35 psi at keeping said tire from exploding like the Ford Exploder tire because you have it overloaded.

Anyone else get the feeling tires and pressures are an art, not a science? It all depends how you use em

[Rick Kirchner]

I used to tech with a ford test engineer. He said the door label pressures were artificially low because they wanted a nice cushy ride off the lot. Evidently, a buckboard ride or the sounds off all the squeeks and rattles cost a lot of money in warranty work.......

I always figured the magic pressure was just like truck tires - a function of load and minimums to keep the tire from overheating and on the rim, but all that would be just too complicated for Joe BagO'donuts, so they make it easy.

I've never heard of a tire blowing out from too much air - there's something like a 200% margin on burst pressure - the rim would probably crack first.

[Rick Kean]

Since the OP has already been banned, I guess asking for "ratio" clarification is mute

[Rick Kirchner]

I thought the single post and nonsensical question was fishy. Must have been a Phisherman....