Tyre pressures

[jacks]

What tyre pressures do people run on their euro's? Someone suggested that increased pressure 38 - 40 psi front - 35 psi rear improves handling and consumption ??? Any ideas??

[Usual Suspect]

u might wanna do a search first dude, there is a thread about this in another section.

[yfin]

What tyre pressures do people run on their euro's? Someone suggested that increased pressure 38 - 40 psi front - 35 psi rear improves handling and consumption ??? Any ideas??

I run from anywhere between 32 to 36.

Running 38-40 will improve handling and consumption - also reduces braking distance in an emergency. The sacrifice is a harsher ride. Another down side of high pressure is huge amounts of wheel hop if you accelerate hard from standing still.

[aaronng]

I run 33psi front and rears. This is the pressure when the tyres are still cold. I don't run any higher because the road conditions here are so poor that the bumpies are starting to give my Euro the rattles.

[coladuna]

I run 43psi at the front and 41psi at the back, but this is usually measured when I've driven the car a bit, not when the tyre's completely cold.
Is this too high? Maybe I should try running lower pressure and see what it's like.

[ECU-MAN]

id say yes it is

[Pum[Z]]

I used to run 40 psi on my tyres but nowdays i run 36-38 psi...

Depends on wat sort of tyres u run on as well..

[VirIIx]

have to agree with Pum[z], i use to do 40 psi, but i just leave em around 35-38.

I'll only use 40 if im goin on a big long road trip nowadays :)

[jtboo]

I run about 38 psi

[viperx]

I run from anywhere between 32 to 36.

Running 38-40 will improve handling and consumption - also reduces braking distance in an emergency. The sacrifice is a harsher ride. Another down side of high pressure is huge amounts of wheel hop if you accelerate hard from standing still.

this is an interesting... i would have thought if there is increased wheel hop it means you are getting less grip because you have decreased the area of your contact patch. if your contact patch is smaller, wont that increase your braking distance??

I think talking about pressures is useless unless we know what tyre, what size rims, width etc. and when you get down to that amount of detail almost everyone is different. for example, i am running 205/55/15 Yoko A539s. Regardless of tyre pressure I am going to get a larger contact patch than most other tyres, because the 539 is renowned for having a hard sidewall. Therefore the tyre pressure I use for the optimum contact patch is likely to be different to the people running on stock tyres.

get out a caliper and measure your tread depths. that is the best way to know.

[yfin]

this is an interesting... i would have thought if there is increased wheel hop it means you are getting less grip because you have decreased the area of your contact patch..

No - higher pressure increases wheel hop. You want more contact patch to put down max traction.


if your contact patch is smaller, wont that increase your braking distance??

This may sound strange - but you want minimal tyre flex in an emergency stop. During emergency situations individual tyres will have 10 - 20 times the normal load. You want maximum possible pressure to ensure tyre will stay on the rim and the footprint to stay in the right place - to allow for maximum traction.


I think talking about pressures is useless unless we know what tyre, what size rims, width etc. and when you get down to that amount of detail almost everyone is different. for example, i am running 205/55/15 Yoko A539s. Regardless of tyre pressure I am going to get a larger contact patch than most other tyres, because the 539 is renowned for having a hard sidewall. Therefore the tyre pressure I use for the optimum contact patch is likely to be different to the people running on stock tyres.

Fair enough - but this is a discussion about Euro tyres. If you run any tyre at the manufacturers maximum - you can't go wrong with handling and consumption.

[stephen8512]

ive experienced wheel hop @ 40psi.....scared the shit outta me at first....
but yeah nowadays, 35-38 is what i put

[viperx]

No - higher pressure increases wheel hop. You want more contact patch to put down max traction.

Mate read my post-
higher pressure increases wheel hop
wheel hop = tyre slipping
tyre slipping due to less grip
less grip = smaller contact patch
therefore pressure too high = smaller contact patch = wheel hop

your tyres bulge more when pressures are too high mate. that is why you wear the centre of your tread faster than your outside. which means the contact patch is mainly the part of the tyre you are wearing- just the centre!

go measure your tread if you don't believe me.


This may sound strange - but you want minimal tyre flex in an emergency stop. During emergency situations individual tyres will have 10 - 20 times the normal load. You want maximum possible pressure to ensure tyre will stay on the rim and the footprint to stay in the right place - to allow for maximum traction.

i'm sorry, tyre pressure has some effect on tyre flex, but not that much. this is more to do with sidewall design. that is why sports tyres are designed with a harder sidewall. imagine a balloon being blown up and a piece of rubber stretched over a cylinder being blown up.



Fair enough - but this is a discussion about Euro tyres. If you run any tyre at the manufacturers maximum - you can't go wrong with handling and consumption.

This is wrong- a manufacturer's maximum refers to the maximum pressure the tyre is able to withstand, not the best pressure for performance. a tyre manufacturer does not include a car's weight into its calculations of maximum pressure- all cars weigh different. imagine a plastic balloon- press it on a table softly and it will still be quite round. press it down hard and a large part of its surface area will be on the table (contact patch). deflate the balloon slightly, and even more of the balloon's surface area will be on the table.

Therefore each car, with each tyre, has a different optimum pressure for the best contact patch.

What kind of handling will you get if you've reduced your contact patch by a large percentage? you're essentially running on skinny tyres.

[EuroAccord13]

I run 36 Front and 34 Rear Cold... But that's for highway driving....