Tyre pressure

[scatman1963]

Hi all I have a gs sport first generation I am wondering what tyre pressure is I got 245/35/18 front rear 275/35/18 I had a puncture last month on the rear and a slow one on the front which turnt out leaking from valve when I asked at this well known garage they said 44psi all round so been running at that I cannot find nothing on any sites so any help would be appreciated I live in the UK 

[NemesisUK]

Use the pressures printed on the label on the driver's B pillar (possibly on the fuel filler flap), also tabled in your handbook 

[m4rkw]

The tyre pressures printed on the pillar are the *minimum* safe pressure and are specified for the OEM tyres which you're almost certainly not running on a 93. Modern tyres are designed to provide a better ride at higher PSI and depending on what tyres you run you may find you experience uneven wear even when running at the pressures printed on the pillar.

A better guide is to look at the tyre sidewalls for the maximum pressure rating and set them to about 10% less than this number. Do this when the tyres are cold. Adjust down as necessary to get a ride that you're happy with. This will give you a much better buffer of safety above the minimum pressure, reduce rolling resistance and maximise the tyre lifespan.

[NemesisUK]

1 hour ago, m4rkw said:

A better guide is to look at the tyre sidewalls for the maximum pressure rating

Must admit to thinking this was the maximum safe inflation pressure for seating the beads on installation, not a safe max running pressure?

Tyre pressures are a function of axle weight and so would be different for different cars. That sidewall value is specific to the tyre, not it's fitment.

[m4rkw]

http://www.agcoauto.com/content/news/p2_articleid/61

This dude knows what he’s talking about.

[DJ Les]

This article is very interesting as a new owner of an RX400H. When I bought the car I checked the tyre pressures, which, according to the Lexus door placard should be 34psi. So, that is the pressures I have been running. However, looking at the car parked outside my house I've been a little concerned that the tyres look under inflated. The MOT that was done the day I bought it mentioned wear on the shoulders which also pointed to being under inflated.

I've took photographs of the complete tyre walls and have discovered that the max pressure is 51psi, quite a bit more than the Lexus door placard. So, I'm going to try putting them up to 45psi and see how they feel while driving.

[m4rkw]

Mine are also rated to 51psi, I run 44 all round just to be safe. The ride is a bit harder but still comfortable enough and you notice the decrease in rolling resistance.

[NemesisUK]

36 minutes ago, m4rkw said:

Mine are also rated to 51psi, I run 44 all round just to be safe. The ride is a bit harder but still comfortable enough and you notice the decrease in rolling resistance.

How's the tyre wear looking?

[m4rkw]

They look pretty even to me