Tyre Pressure

[Jono.c]

Hey guys.

I'm running 195/50 (Kumho Ku31) tyres on 15x8 rims

The place that fitted the tyres put 45psi in them. The front end is now so raily and sledgy, bump steers like a biatch.

The car is daily'd and therefore needs to be able to withstand potholes etc if need be..

Just wondering if anyone knew roughly what the minimum i can run in it is?

Now i know the answers i'll get will either be "Lol get some proper tyres that fit" "Google it" or "You retard read the sidewall"

But the main factor of this is they're stretched.. Not massively, But enough that under-inflation would probably result in the tyres popping off..


I was hoping to run around the 36 mark..


Any ideas, formulas, experience or ideas would be greatly appreciated.

Cheers!

[SumKid]

I'd say 36 would be fine, 45 just seems like the amount they put in there to pop it onto the bead! Could always try 32 if you wanted it lower and see how it looks/feels.

A mate has same amount of stretch as you same rim width and he has done a motor Khana with them at 36.

Hope that helps.

[Rob5000]

If its front wheel drive I'd run 40psi. 45psi tho is way to high for road use. On my rear wheel drive cars I run 38psi.

[CELICASUPRA7M]

Lol get some proper tyres that fit" "Google it" or "You retard read the sidewall

[Hiro]

"Reading the sidewall" is useless as they only mention maximum rated pressure, not recommended...

[maj]

Tyre placard is always best, which is not on the tyre itself, usually in the door sill.

Can't say regarding stretched tyres, but I run 36 on a loaded up car, or 34 every other time. I use N27 nitrogen at 34 regardless of load.

Definitely sounds like 45 was used to pop it on the bead. Usually if they leak they pump them up to 60 so they can more easily see where the leak is.
Do not pump it up to the max PSI. My missus was complaining to me once that her car felt funny, I said check the tyre pressures, they should be 34.
She forgot the number and asked her old man to check, being the knowledgeable car guy he is, he pumped them up to 56, missus was then complaining to me her car was bouncing along the highway. So lucky her tyres didn't pop.

[Jono.c]

Wound it down to 36psi all-round. I'll see how that goes

One rear was 45 and the other was 37.. No wonder it felt funny


Cheers guys!

[aus jd 2703]

just a slight thread highjack,
roughly what pressure should you run in a low profile tyre?
im running federal 595EVO's in 215/45 17r on 17x8's?
been told anywhere from 33 to 40psi??
currently at 37PSI, tyre placard says 32PSI but thats for the stock 215/50 15R.

[SumKid]

I run 38psi in my Lexus tyres which are 245/35r19, but I'd run, like you said anywhere from 32-38.

Cheers

[ctrain]

i ran 32psi on my 15x8 with 195 on the front and it was fine, no eneven tread wear, and the ride with still smooth with lowered springs.

[marvis]

I run 32 cold in mine on z10. Re002, daily and drifting.

[greg]

I find it interesting,that in a country that went metric over 40 years ago that we all (myself included) refer to tyre pressures in PSI. back to something more relevant,best inflation for a given tyre size eg; 195/50/15 will vary not only with the use such as road/race/kana but more importantly on the weight of the particular vehicle the tyre is fitted to. a 900kg corolla will operate on a lower pressure than a 1550kg cressida with the same tyre. trial and error is probably the best way to find what suits both you and your toy.
cheers greg.

[Hiro]

I find it interesting,that in a country that went metric over 40 years ago that we all (myself included) refer to tyre pressures in PSI. back to something more relevant,best inflation for a given tyre size eg; 195/50/15 will vary not only with the use such as road/race/kana but more importantly on the weight of the particular vehicle the tyre is fitted to. a 900kg corolla will operate on a lower pressure than a 1550kg cressida with the same tyre. trial and error is probably the best way to find what suits both you and your toy.
cheers greg.

Most air pumps at servos have both PSI and kPa on the gauges. I think it is more the tyre companies rather than the country - remember this is an industry that uses Metric, Imperial AND a percentage all on the one designation (width in mm, sidewall height in %, and diameter in inches)