Hi,

The tires of my previous car were supposed to be inflated to around 2.1 Bar (=31 PSI). The tires of my new V40 are also supposed to be inflated to approxemately 2.1 Bar (31 PSI). Exept the reserve wheel. It is supposed to be inflated up to 4.2 Bar (=60 PSI). And you're is only allowed to drive up to speeds of 80 kilometers an hour.

When I checked the tire was only inflated up to 2.0 Bar. What should I do? 4.2 is almost twice the normal pressure!! On the tire it says 4.2 Bar (420 kPA).

Thanks for your advice! B.

:grin: Hi there B.

If your spare tyre is a T125/90 R15 96M then the correct air pressure is 420 kPA. The previous owner seems to have neglected the spare tyre somewhat!

If you let the pressure fall too low then the sidewall may detach from the steel road wheel rim and make reinflation difficult. If you over-inflate you might cause permanent bulging &/or weakness of the tyre.

The reason for such high pressure is that you are asking a very narrow tyre to carry the same weight, cornering, acceleration & braking loads as say a full 195 or 205 width tyre. The "special spare" weight/fuelsaver is meant as a temporary, get-you-home only tyre and is not designed to take the stresses & temperatures generated by prolonged high speed driving, so it is dangerous to exceed 80 km/h when this tyre is fitted.

Please check your owner's manual carefully for correct tyre pressures - I have a manual for 2001 UK model S40 & V40 cars and tyre pressures are not shown as 210 kPA. If you don't have a manual then there may be a sticker inside on of the front doors or inside the fuel flap or glove compartment perhaps? What engine variant & tyre size do you have?

Like BB said, its likely the dounut spare, and is supposed to have that much inflation. IF u dont have the owners maunal, do what it says on the sidewall.