Tyre Pressure

[Jessi]

Seems to be a few members on here that have knowledge about tyres.

I have Bridgestone 195/55 R15 tyres on my corolla, at the tyre shop they told me to put 36 psi, I thought that a bit much.

What pressure would the experts on TV suggest?

Many thanks.

[transam]

Open the drivers door, there should be a sticker telling you all about the rides tyre pressures. Your hand book will too. Don't listen to anybody AND buy a pressure gauge in Tesco.....

[StefanBBK]

Funny, I my door said 27. Toyota service put 30. They said it would be better. Back home I reduced it to 27 again......

Sent from my GT-I9500 using Thaivisa Connect Thailand mobile app

[Jessi]

I will have a look on the door tomorrow, I have a tyre guage thanks tranny.

[wilcopops]

I don't know why but there seems to be a habit throughout Thailand of over-inflating tires - or at least inflating the way above the manufacturer's specs, which as has been said are usually on a sticker on the sill inside the driver's door.

It really is a good idea to have a gauge too.

[Gonsalviz]

My truck says 27 in the front door. Everyone puts 45 in them. I let some out and it gets put back to 45. I have the longest wearing tires I have ever seen. 2 tires now have 177,000 Km on them and lots to go. The other 2 originals were replaced for side wall damage. All tires wear evenly. I would have thought the rears would require less because I rarely carry anything.

So I guess 45 is it.

[transam]

My truck says 27 in the front door. Everyone puts 45 in them. I let some out and it gets put back to 45. I have the longest wearing tires I have ever seen. 2 tires now have 177,000 Km on them and lots to go. The other 2 originals were replaced for side wall damage. All tires wear evenly. I would have thought the rears would require less because I rarely carry anything.

So I guess 45 is it.

Your ride will/does ride like shit. Have you bumps on your head from roof contact.........

[WarpSpeed]

Funny, I my door said 27. Toyota service put 30. They said it would be better. Back home I reduced it to 27 again......

Sent from my GT-I9500 using Thaivisa Connect Thailand mobile app

My feeling is they were correct.. But anyway..

[WarpSpeed]

I don't know why but there seems to be a habit throughout Thailand of over-inflating tires - or at least inflating the way above the manufacturer's specs, which as has been said are usually on a sticker on the sill inside the driver's door.

It really is a good idea to have a gauge too.

The pressures only apply to original OEM tires, not every brand, I.E. replacement tires .. Funny that when at the race track the opposite applies, they usually under-inflate.... Considerably....

[Pralaad]

I do 30 and seems to work well

[WarpSpeed]

My truck says 27 in the front door. Everyone puts 45 in them. I let some out and it gets put back to 45. I have the longest wearing tires I have ever seen. 2 tires now have 177,000 Km on them and lots to go. The other 2 originals were replaced for side wall damage. All tires wear evenly. I would have thought the rears would require less because I rarely carry anything.

So I guess 45 is it.

Your ride will/does ride like shit. Have you bumps on your head from roof contact.........

Maybe but it's not supposed to be about comfort is it? Especially with truck tires you don't want dangerous rollover of the sidewall.. Having said that I think 45 is probably a fair bit high though given the recommended pressure there is a lot of room for adjustment and compromise there.

[David48]

I was salivating when I read the title of the OP ...

The most famous debate here on the Motoring Forum in my memory.

I would warmly suggest that 32 PSI is an appropriate compromise between ride comfort and tyre, thus fuel economy.

The higher the pressure (up to a point) the better the 'gas-mileage', but the flip side of the coin is a harsher ride.

Personally, I usually run 36 ish ... but I'm careful with my Baht.

So .. some images ...

But the most fun ...

[Carib]

Shall I get the popcorn and the drinks?

[Mrjlh]

32 PSI is the norm for most tires. Higher for trucks but don't fall for what is written on the tire. That's the MAX pressure. Hit a pothole and your done. There are tires built that required a different pressure such as a "very low profile" tire but the general accepted rule is 32 PSI.

[Jessi]

Shall I get the popcorn and the drinks?

Mate, can you grab some peanuts also...........I like peanuts or donuts with my coffee.

[Jessi]

I was salivating when I read the title of the OP ...

The most famous debate here on the Motoring Forum in my memory.

I would warmly suggest that 32 PSI is an appropriate compromise between ride comfort and tyre, thus fuel economy.

The higher the pressure (up to a point) the better the 'gas-mileage', but the flip side of the coin is a harsher ride.

Personally, I usually run 36 ish ... but I'm careful with my Baht.

So .. some images ...

But the most fun ...

Over inflated tyres have less grip so not so good with the wet season coming.

I am looking for a good pressure for comfort and safety, gota look after mrs jessi and the 2 kids.

[WarpSpeed]

I think you'll find that David has a newborn himself.. I would say for the tires he has/had (don't know if they're still the same) he'd do well with 34 front and 32 rear..

Curious though where did you get the less grip theory? Though "over inflation" is never recommended that is a subjective & general description. But an over inflated tire actually moves more water as it opens up the treads, so to say that "an over inflated tire" does not grip as well in the wet is not an entirely true statement a lot of factors come into play not the least of which is, WHICH tire brand and size you're referring to specifically, a truck tire will likely be an issue as they suck in the rain in any case so the last thing you want is an inflexible tread due to over-inflation as they already have too much flat rubber per surface area to hydroplane on.

[Jessi]

I think you'll find that David has a newborn himself.. I would say for the tires he has/had (don't know if they're still the same) he'd do well with 34 front and 32 rear..

Curious though where did you get the less grip theory? Though "over inflation" is never recommended that is a subjective & general description. But an over inflated tire actually moves more water as it opens up the treads, so to say that "an over inflated tire" does not grip as well in the wet is not an entirely true statement a lot of factors come into play not the least of which is, WHICH tire brand and size you're referring to specifically, a truck tire will likely be an issue as they suck in the rain in any case so the last thing you want is an inflexible tread due to over-inflation as they already have too much flat rubber per surface area to hydroplane on.

Over inflated tyre means less rubber on the road, IMO means less grip in the wet but warpy Im no expert, hence my question on this tyre pressure.

[WarpSpeed]

But in wet conditions more rubber is not optimum, more grip is and that is due to moving more water. Large tires like truck tires have worse grip then do car tires because they have too much rubber on the road (a larger foot print) and act like slicks.. The same applies to snow and ice when smaller tires are commonly used as it cuts through the wet and grips better instead of sliding, for obvious reasons water and hydroplaning is very much the same.. When we race in the rain we put on thinner tires with more tread to optimize water movement and so the tire cuts through the water instead of riding on top of it at speed..

When you over inflate the tire it gets wider, opens up the treads, but has a smaller foot print so in a sense makes the contact patch smaller and cuts through the water, plus it also heats up quicker and a hot tire grips better. Reference Davids post with the pictures and see how the over inflated tire crowns and opens up the treads and the contact patch is smaller. Understand I'm not suggesting over inflation, but rather perfect inflation, the problem is the word "over inflation" being bandied around without specific context as it doesn't apply in all cases, too much generalizing going on..

Perfect inflation is not what's listed in your door but rather is something between max inflation and that which is listed as the OEM pressure as it serves as a compromise by the manufacturer to provide the best ride characteristics over all, those are comfort, compliance (performance) and fuel mileage.. If you slightly increase pressure (maybe 4 to 6 pounds max) you will increase tire performance (react quicker and more precisely when you need to evade something/someone), fuel mileage, and tire longevity but decrease ride comfort, that's the only down side to slightly increased tire pressures. So if your backside is too soft go softer tire pressures ..

[transam]

Go bye the sticker on the door pillar. It will even tell you if to up the pressure with a load. The vigo has the same pressures all round loaded or not.

Vigo from factory has either Bridgestone or Michelin tyres and use the same pressures. An over inflated tyre does not allow radial sidewalls to do their job and you will wear out the centre of the tyre.

Manufactures go to great lengths to find a pressure best suited for a particular ride, the main issue being safety. Deviate from their advice at your peril.

[WarpSpeed]

No the main issue to the manufacturer, as you already noted is ride quality.

[transam]

Ride quality is achieved by a combination of suspension and tyre sidewall flex or just suspension in the case of rides with very little tyre sidewall.

On a truck the tyre sidewall is a part of suspension and ride quality. I have experimented on my truck just to see the difference. Though 29psi is recommended on my 4x4, I settled for 30 rear, 32 front.

[MMarlow]

Ride quality is achieved by a combination of suspension and tyre sidewall flex or just suspension in the case of rides with very little tyre sidewall.

On a truck the tyre sidewall is a part of suspension and ride quality. I have experimented on my truck just to see the difference. Though 29psi is recommended on my 4x4, I settled for 30 rear, 32 front.

Did you notice a lot of difference in ride quality when you adjusted the pressures from 29 to 30psi?

[WarpSpeed]

^^ Conclusion is, you agree...Ouch, that must hurt..

[transam]

Ride quality is achieved by a combination of suspension and tyre sidewall flex or just suspension in the case of rides with very little tyre sidewall.

On a truck the tyre sidewall is a part of suspension and ride quality. I have experimented on my truck just to see the difference. Though 29psi is recommended on my 4x4, I settled for 30 rear, 32 front.

Did you notice a lot of difference in ride quality when you adjusted the pressures from 29 to 30psi?

Simply liked the mark on my pressure gauge. . 29 psi is 2 Bar, Toyota obviously settled for 2 Bar.

Because my ride has the extra weight of the 4x4 and the auto trans compared to a basic manual truck l thought l could improve my "feel". I tried 35psi in the front at first but the ride quality was crap, so settled on 32psi. Tyre wear is even across the tread so think I have got it about right...

[culicine]

So if 32 psi is a rule of thumb (for sedans), is this a warm or cold pressure? When you drive to the garage your tires will be warm. You inflate to 32 psi, but when they cool they will be less (by how much I don't know). I have an electric pump and can inflate cold. If inflating to 32, it will increase above then when driving. I usually go for 32 (up to 34/35 on occasion, but the ride is harder).

[transam]

Buy a gauge and cheap pump and test them in the morning before you drive.

[stubuzz]

My car's recommended tyre pressure is 32. After driving for a while, they reach 34-35psi. Nitrogen will overcome this problem, i think it is lighter than air, too

[transam]

My car's recommended tyre pressure is 32. After driving for a while, they reach 34-35psi. Nitrogen will overcome this problem, i think it is lighter than air, too

That is what it is meant to do.............. ......Thats why they say set pressure cold.....

[David48]

My car's recommended tyre pressure is 32. After driving for a while, they reach 34-35psi. Nitrogen will overcome this problem, i think it is lighter than air, too

That is what it is meant to do.............. ......Thats why they say set pressure cold.....

Agreeing with transam ... you normally test the tyre pressure when cold.

It's usual for the tyre pressure to raise as the heat builds up in the tyre.

As for how Nitrogen reacts with increased temperature ... I have no idea.

.