Tyre Pressures (Help)

[MacXC60T5]

When I had my new Michelin Pilot Sport 3 tyres fitted to my AWD S6T6 Tyre size 275 x 40 x 18 Speed rating Y. they had pressures all round of 31.5 psi. When I viewed the Michelin site they state the pressure should be 34.8 all round. When I read the Manual it gives me pressures of Front 300(kPa)8 Rear 240 kPa. Can some kind person give me guidance to what pressures I should be using average two up never loaded. Something seems to be a bit a drift and I can't put my finger on it.

[stephenevans99]

Personally I'd inflate both front & rears to 35psi and see how it feels.

300 kPa converts to 43.5 psi which seems a lot for the fronts tbh

[stribo]

In the S60R we have 35 psi all round. It should say inside the fuel filler flap.

[jamesy12345]

Maybe 300 kPa is for high speed (100 mph+)/full load

[Blackdog]

In the S60R we have 35 psi all round. It should say inside the fuel filler flap.

On the newer cars there is a sticker on the pillar when you open the drivers door rather than inside the fuel filler flap.

[stribo]

On the newer cars there is a sticker on the pillar when you open the drivers door rather than inside the fuel filler flap.

Are you calling our car old?

[Blackdog]

It all depends on your reference point. Compared to my V70 then yes. Compared to mr Mrs '99 V70 then no.

[stribo]

It all depends on your reference point. Compared to my V70 then yes. Compared to mr Mrs '99 V70 then no.

Very diplomatic lol

[jamesy12345]

When I had my new Michelin Pilot Sport 3 tyres fitted to my AWD S6T6 Tyre size 275 x 40 x 18 Speed rating Y. they had pressures all round of 31.5 psi. When I viewed the Michelin site they state the pressure should be 34.8 all round. When I read the Manual it gives me pressures of Front 300(kPa)8 Rear 240 kPa. Can some kind person give me guidance to what pressures I should be using average two up never loaded. Something seems to be a bit a drift and I can't put my finger on it.

Here's a guide

http://www.f1autocentres.co.uk/car-tyre-pressures.php

but as above look behind the filler cap or B-post

assume you meant 235/40 x 18

[MacXC60T5]

Should have looked on the pillar post as it states 35 psi to front and rear. So the information on the Michelin site is correct at 34.8 psi. Wonder why the garage only put in 31.5. I suppose to be safe, but pissed me off a bit as they should have checked the information. Thanks for the help chaps and sorry to be a bit of an idiot.