Tyre pressure

[Mk6tsi]

Just wanted to know what your tyre pressure is normally set at or what you prefer. Front/Rear.

Oem or non oem Tyres.

If you guys could post your readings that be great.

[Mk6tsi]

Today checked my tyres which are the oem ones I got when I purchased.
It read 40psi front.
42 rear.
Found this quite odd as I have never touched this since I got it.
Very odd.
I set it at 38 all around.
Is this what I should be doing?

[_Just]

Mine are 19" Telladega's with 235/35 tyres.

They are 42psi all round!

[ozmale]

Guys you are not going to like this.

I am sorry to tell you but the manufacturer really pays no attention to tyre pressures (except maximiums and Rolls Royce). Air is placed in the tyres by the p redelivery detailers with really not much thought at all.

I did a fairly long and drawn out experiment with my WRX STI where I lowered all the pressures considerably then drove a specific route (round the block if you like) and felt the ride. Then increased the pressures by 2 lbs and did it again and again. Most of the time the ride was pretty harsh then all of a sudden at only one pressure setting the car glided down the road and handled great. Bumps were smooth like low frequency thuds and the car just sat on the road. Then 2 lbs above this pressure it started to ride like a truck getting worse as I increased the pressure. My end result was 4bls greater than OEM in front and 6lbs less in rear.

A cars suspension system is a tuned resonance with lots of factors involved. The test I did is the only way to get it right that I can think of. When I changed tyre brands (but not sizes) my setting were completely wrong again. There was a 6 lb difference needed from the previous setting.

It is my understanding that these cars can be delivered with a variety of different tyre brands so what one guys uses will not be right for another. I do not have my "R" yet but I will be doing my test again when I get it.

[mr gee]

Guys you are not going to like this.

I am sorry to tell you but the manufacturer really pays no attention to tyre pressures (except maximiums and Rolls Royce). Air is placed in the tyres by the p redelivery detailers with really not much thought at all.

I did a fairly long and drawn out experiment with my WRX STI where I lowered all the pressures considerably then drove a specific route (round the block if you like) and felt the ride. Then increased the pressures by 2 lbs and did it again and again. Most of the time the ride was pretty harsh then all of a sudden at only one pressure setting the car glided down the road and handled great. Bumps were smooth like low frequency thuds and the car just sat on the road. Then 2 lbs above this pressure it started to ride like a truck getting worse as I increased the pressure. My end result was 4bls greater than OEM in front and 6lbs less in rear.

A cars suspension system is a tuned resonance with lots of factors involved. The test I did is the only way to get it right that I can think of. When I changed tyre brands (but not sizes) my setting were completely wrong again. There was a 6 lb difference needed from the previous setting.

It is my understanding that these cars can be delivered with a variety of different tyre brands so what one guys uses will not be right for another. I do not have my "R" yet but I will be doing my test again when I get it.


+1 for your write up. though I don't go to such lengths,

[ozmale]

If you really want to read a lot about tyre pressures download and read this Government report on tyre pressures and accidents.
Basically if you look at the REAL accident causes and statistics we would be booking people for incorrectly inflated tyres rather than speeding.
The report clearly states that under inflated tyres and the resulting loss of control is a bigger contributor to accidents than speeding.

http://www.maic.qld.gov.au/forms-publications-stats/pdfs/tyre-pressure-report-final.pdf

This PDF document also has great info on how to calculate and a table for substitute tyre pressures.

Pages B12-B14 are the tables.

http://www.tiresafety.com/images/Tire%20Replacement%20Manual.pdf

[Christian]

Mine are 19" Telladega's with 235/35 tyres.

They are 42psi all round!

Hi Justin - any chance of some pics of your car? Or are there already some on here somewhere :-)

[_Just]

Hi Justin - any chance of some pics of your car? Or are there already some on here somewhere :-)
Nope. I promise I'll get some shots soon. I'm just useless with a camera, so am waiting for a mate to get some shots for me.

This one was with the iPhone shortly after picking up the car a few weeks ago.

http://27.media.tumblr.com/tumblr_lcwacuCGpI1qev61uo1_500.jpg

[fuzion]

After working a bit in the tyre/wheel industry i wouldnt recommend 42psi to be completely honest, max 38psi but 34-36 is perfect and especially for tyre wear on 18/19s.

Another good option is get yourself some nitrogen in the tyres so it holds pressure and you wont have to check as much, many benefits for road use you'll get out of it ..

just my 2psi :P

[PTW]

Guys you are not going to like this.

I am sorry to tell you but the manufacturer really pays no attention to tyre pressures (except maximiums and Rolls Royce). Air is placed in the tyres by the p redelivery detailers with really not much thought at all.

I did a fairly long and drawn out experiment with my WRX STI where I lowered all the pressures considerably then drove a specific route (round the block if you like) and felt the ride. Then increased the pressures by 2 lbs and did it again and again. Most of the time the ride was pretty harsh then all of a sudden at only one pressure setting the car glided down the road and handled great. Bumps were smooth like low frequency thuds and the car just sat on the road. Then 2 lbs above this pressure it started to ride like a truck getting worse as I increased the pressure. My end result was 4bls greater than OEM in front and 6lbs less in rear.

A cars suspension system is a tuned resonance with lots of factors involved. The test I did is the only way to get it right that I can think of. When I changed tyre brands (but not sizes) my setting were completely wrong again. There was a 6 lb difference needed from the previous setting.

It is my understanding that these cars can be delivered with a variety of different tyre brands so what one guys uses will not be right for another. I do not have my "R" yet but I will be doing my test again when I get it.

So what were the results now you have an R?

[ozmale]

Now that is a good question. Yep a while back I did the exact same experiment as I did on my WRX.
However i not not tell any definitive point at where the handling or ride changed that much. Pressures from as low as 32 up to 40 did not seem to make a difference.

That led me to conclude that the WRX as less sophisticated suspension than an "R" and the "R" is not that dependent on tyre pressures. Given my setup I decided that 38psi all round was the best.

Chris

[chylld]

my dealer said 40psi all round (235/35R19) - haven't checked them yet though.

i ran 36psi all round on my previous car (18" tyres) and the first set of tyres only lasted 20k kms - all 4 tyres were worn down on the shoulders, indicating lack of pressure. of course pumping it up to 36 means on average it would have been around 33-34psi; so topping up to 40 gives about 37-38 which agrees with the other comments here :)

[totogti]

Tyre Pressure, apart from safety and wear, is also about the driving you are intending on doing.

If you are on a race track then it is entirely based on track conditions, even as so far as the wheel alignment of the car.

A lot of smart and very technically minded people monitor and make decisions on what pressure is correct, so it may be difficult to be entirely precise and come to a understanding that if you race around a suburban road and that being as a novice you will find optimum tyre pressure. Not to mention after a few laps around the street you will create heat in the tyre and it will act differently anyway.

I too found the tablet odd for the MK6 GTi, as back in the days of doing the Audi track days at oran park, the instructor advised us that FWD cars should always be 2psi greater at the front due to engine load and drivetrain.

A simpleton rule of thumb is:

Highway K's can have more pressure, as there is less cornering apparent and you will arch the tyre to use more of the middle tread and have a decrease petrol consumption due to less wheel resistance. Think of your bicycle, high tyre pressure less tyre resistance easier to pedal, low tyre pressure, more resistance, harder to pedal.

Day to day driving: lower pressure, this is order to cope with increase braking and cornering.

I have also played around with the psi, though find the weird tablet set up the best.

When getting your tyres done ask the store to advise and show you how the tyre performs and what is best for Psi.

It is advised you should check tyre pressures every month. Tyres are the only thing your car has that touches the ground and in Australia we are very naive when it comes to tyre maintenance.

If it was a Ford BA sedan I could understand that the tablet to be little off, though the GTi is a sports hatch and it is likely VAG would take attention to what tyre pressure would be best for OEM balance and handling.

http://www.tyrepower.com.au/tyre_pressures.aspx