Tyres over inflated. Does it matter?

[NVP]

 

[Duke]

Sure you could fit a bit more air in them? Give it a try but make sure the car is tethered to the ground.

 

[Hawk Tuah]

60 is very high, probably very close to the maximum the tyre is safely rated for, it will wear his tyres in the middle much faster, reduce grip and traction as said above, but on the plus side better effiecienciessss . but yea dial it down to 40psi max. 60psi is stupid high for a standard car.

This is simply not true with modern radial tyres.

 

[SkodaMart]

This is simply not true with modern radial tyres.

I agree with Rich1988's comments.

Please explain?

 

[Hawk Tuah]

On my car, the recommended inflation is between 36 and 39 if I recall well.

I had to inflate them a few weeks ago as they were very low (around 29 I think), and I was about to be involved in a crash. I had sun in my eyes and I was coming out of a roundabout and the car in front of me decided to stop (there was someone crossing). I had the sun in my eyes and I didn't see the brake lights (car was silver, so sun was reflecting a bit). Put my foot down on the brakes and stopped just in time.

I feel that if they were inflated, I would have hit the poor car in front of me!

In fact, after inflating them, I had to smash the brakes again. This time I didn't notice the pelican crossing turned orange (its a main road, where everyone is going 80 km/h, why would you do a pelican crossing there?!?!) and I smashed the brakes again. This time the stopping distance was MUCH longer (although I was going a bit faster). The tyres are inflated at around 42.

So yes, it makes a difference. And it can prevent a crash. Inflate them every 6 weeks, and keep within the range.

I'd be more concerned why you're continually having to mash the brakes. Most drivers don't.

 

[Hawk Tuah]

I agree with Rich1988's comments.

Please explain?

A tyre is not like a balloon. Over inflation will make the sidewalls harder and therefore reduce your contact patch front to back. But the metal rings around the tyre will prevent it crowning.

 

[Hawk Tuah]

http://www.barrystiretech.com/footprintsmall.jpg

This is what I mean. The contact patch shortens, but the whole width of the tyre is still contacting evenly.

 

[SkodaMart]

http://www.barrystiretech.com/footprintsmall.jpg

This is what I mean. The contact patch shortens, but the whole width of the tyre is still contacting evenly.

Surprised at that!

 

[silversurfer]

Higher psi would be less rolling resistance but also less grip, so would likely increase breaking distance I think

 

[malfunkshun]

Surprised at that!

I suspect that Michelin, Toyo and Continental (those are just the manufacturers websites that I could be bothered to check) would be too, as would various Governments and tyre suppliers......

 

[Something Else]

On the side of the tyre should be the max pressure for that tyre.

I usually stick 36-37psi in my tyres, reccomended is 30 and rating on the tyre is 50psi iirc.

I find that at around 36-37 it tramlines less, feels better through the wheel and generally feels nicer to drive.

 

[Deleted member 66701]

Is your dad a Japanese drift fiend?

If not, can't go far wrong with this..

http://www.kwik-fit.com/tyre-pressure-search.asp

Yeah.

Except it lists the wrong size tyres for my car!

 

[Rich1988]

A tyre is not like a balloon. Over inflation will make the sidewalls harder and therefore reduce your contact patch front to back. But the metal rings around the tyre will prevent it crowning.

I can only go from my own experience, I run my astra tyres at 40psi and the centre wore faster than the shoulders on all four corners so I lowered the pressures to 32.

 

[Scania]

Mine are at 125psi, it is a 44t HGV though!

I can't imagine how awful the ops dad's car must be to drive, nor how he's avoided a blowout and / or accident!

 

[snips86x]

But the MPGz!

I do 32/34 all round.

What's is he driving to run at 60? The ride must be solid.

My 2002 Fiesta I think is recommended at 25-28 which I find is waaaay too low. Running at 32/34psi gives me about 65-70mpg and in all honesty, the tyre wear is not uneven.

 

[Sasso]

kia rio banging around the 33psi mark (push bike takes 100psi )

get pretty even wear all round I think.... which reminds me, quick look at mine the other day and wearing a bit thin now on the front so shall have to have a closer look tonight and maybe get some new soles on her.

 

[acemastr]

Fairly sure 60psi is the pressure they use to seat the tires on the rim!

 

[Jonnycoupe]

A tyre is not like a balloon. Over inflation will make the sidewalls harder and therefore reduce your contact patch front to back. But the metal rings around the tyre will prevent it crowning.

Exactly. My RE92 tyres are worn now.

45psi and its the shoulders that have worn not the centre where there is probably an extra 2mm of tread.

 

[bledd]

Yeah.

Except it lists the wrong size tyres for my car!

Mine too, but I'm sure it would recommend a healthier number than 60 for PSI.

 

[Fido McNasty]

So I was speaking to my father and we were on the subject of tyres. Now I do believe the average PSI for a car tyre is around 26 max? (For my dads tyre) but I just found out he runs all tyres at 60 PSI!! Now I've driven his car, it glides down the road lol, but the ride is so bumpy. Now driving at this PSI, is it dangerous as his max PSI is around 26?

A tyre is not like a balloon. Over inflation will make the sidewalls harder and therefore reduce your contact patch front to back. But the metal rings around the tyre will prevent it crowning.

My 2002 Fiesta I think is recommended at 25-28 which I find is waaaay too low. Running at 32/34psi gives me about 65-70mpg and in all honesty, the tyre wear is not uneven.

*walks away stunned...