Official tyre pressures too high?

[Andy ap]

Had new tyres fitted last week (Toyo T1r's 94Y XL) to the front and i was checking the tyre pressure. Under the filler cap it says 2.7 bar or 39 Psi for the fronts which surprised me a bit so tried that and on the motorway the steering felt disconcertingly light and OK in sport.

So i dropped it to 36 which is more of a pressure i'm used too and in sport the steering was firm with a noticeable self centring feel but about right on motorway dual carriageway etc.

I'm now splitting the difference and still feel its a bit hard, These tyres XL load are higher load and speed rated than standard so i'm thinking that the recommended pressure is just to high?

 

[Copra68]

The XL rating won't help either, I've noticed garages try and flog you them despite wanting an exact standard match to what the car should have as standard and XL rated isn't standard fit.

 

[LouG]

There is a technique for bike tyres where you run them up to normal operating temps, 30 - 40 kms or so in 20C ambient and check pressures.
If cold temps were right, they should now be around 10% higher.
I've not tried it on cars yet, must give it a go. This would be more suitable for high and extreme performance tyres.

 

[CUPRoAr]

I dont put 39psi in my tyres either as the sidewalls are pretty hard and the lower pressure helps the tyre to warm up.
I would be careful putting too little pressure in the t1r, as its not got a stiff sidewall and if you hit a pothole it will more than likely knacker your wheel.

 

[BoomerBoom]

The recommended pressures are so the car can achieve the official fuel consumption figures, mine also has a comfort value on the label so even Seat acknowledge the values are a little high for normal use.

However, I'm only on 17" rims. If you've got 19" then there's less room for movement as above.

 

[Andy ap]

The recommended pressures are so the car can achieve the official fuel consumption figures, mine also has a comfort value on the label so even Seat acknowledge the values are a little high for normal use.

However, I'm only on 17" rims. If you've got 19" then there's less room for movement as above.

I'm on the 17's too (our roads are just too **** for rubber bands ). Yep i think it will be back to the comfort setting of 36.