Tyre question.

[Tanzy]

I think any more than a 10 minutes drive will heat up the tyres to a point that the pressure will be inaccurate from cold tyre pressure. Try to do it in the morning.

The higher the pressure, the less side wall flex there is for the piece of rubber between the rim and the road. Imagine, if you were to take a piece of rubber and keep bending it back and forth for a few minutes. It is going to get hot. The same will apply to the tyres, as the rubber rolls under the rim, it bends under the weight of the vehicle, but once it rolls up and away, it bounces back to it's original shape. This is going to go on for hours at high speed resulting in fatigue of the material.

Units, I think you mean Kilo Pascals (kPa) and not Pounds per Square Inch (PSI)

 

[emiffy]

On the night before your trip, go to the nearest petrol station, and overpump it by 20%, drive it gently back home.

First thing the next morning, check the tire pressure and release the air so that you get the correct cold air pressure.

p/s: I think the units you have quoted are for kPa. If it's 200 PSI, your tire would have already burst!!!

 

[Racebred]

actually so long as you are within that region, its all ok. the tolerance level is quite big anyways, and the safe zone is pretty wide. so if you're like 0.5 bar either side of recommended, i guess it'll still be ok. but better to be higher than lower.

usually i dont bother myself with hot pressure or cold pressure. I go when I have the time. When i pump air into hot tyres, I just increase it by say 0.2-0.3bar more. Even if it's not accurate, it's still well within the safe limits.

Even when i'm pumping up tyres to go tracking. As for fine tuning your air to the exact psi, it only works for extreme tracking as it affects the feel and handling of the car. Even for me, i just drive and track the car according to what it has, and can do. i never need to play with tyre pressures, too high level liao.

so, for a trip like 6 hr cameron, just make sure you're not those kind of kuku driver who dont check pressure for 9 months and am running around on 1.5 bar pressure kind.

In that kind of scenario, your tyre will heat up, bulge and expand at the weakest point in the sidewall or contact patch, and burst out. If the burst pressure is not great, then the wire mesh will still hold the tyre together, but if the tyre is too old, it'll disintegrate and your car will probably flip.

so for you, especially since your tyres are still new, if you are around that recommended pressure, this kind of thing is no problem one. can even drive to russia.

 

[T6]

I read that it is recommended that tyres should be pumped when cold and the guide is not to drive the car beyond 2km before pumping the tyres so that the tyres are not warmed up yet and reading would be accurate (assuming cold engine and car not driven earlier on). Not a problem for me as lots of gas stations around my place. But might pose a problem for others and that's where Emiffy's suggestion come in handy. But dun go and release too much air and gotto to do the whole exercise again

 

[lecabrio]

I read that it is recommended that tyres should be pumped when cold and the guide is not to drive the car beyond 2km before pumping the tyres so that the tyres are not warmed up yet and reading would be accurate (assuming cold engine and car not driven earlier on). Not a problem for me as lots of gas stations around my place. But might pose a problem for others and that's where Emiffy's suggestion come in handy. But dun go and release too much air and gotto to do the whole exercise again

Btw you can pump it more and release the air next morning when tyres are cold to the correct cold air temp.
Cheers

 

[Ghostrider]

Driving for around 1.5km is warm enough for you not to take the pressure. But from what I find is that between warm and cold pressure, the PSI level is about 1-1.5 points. So if nearest petrol station is not within 1.5km, I suggest you pump in 3-4 PSI of your desired pressure...drive home then release the excess pressure the next morning.

 

[DreamDriver]

Guys, just curious to know: what is the minimum/average cooling period for warm tyres, assuming:

(1) normal driving for 30km or so before parking, and
(2) car is parked in a cool, sheltered lot

 

[7]

Usually I pump the tyres early in the morning before 7am enroute to work. Though the petrol station is about 1.5km from my home, I always release the warm air in the front tyres until I can feel the cold air coming out. The air in the front tyres is quite warm more because of the engine than the distance travelled.

 

[gwumpkus]

hey u guys, since we're on the subject of tyre pressure... mine says n the tire Max=300KPa (40 Psi).. ZR16/50/225 CSC's... does everyone just do as the tyre says and go for the 300Kpa pressure?..sounds like a far cry from the 220-230 i used to pump into the stock tyres on my E36... thanx for the advice..

cheers!

michael