Can anyone help ? I've looked here and online but cannot seem to find an answer. Simple question: what pressure should I have my tyres at ? The car is a 340 and the tyres are Federal 185/R15 93T. Ant advice would be much appreciated.

 

30 to 35 PSI
Anything less then 30 is too soft _ car won't handle and anything more then 35 will be too hard _ harsh ride.

 

I keep my fronts at 33 and the rears at 32.

 

I've been wondering what a sensible pressure is for an S Type. It's heavier than a Mk2. I have mine at 2.3 bar ~ 33 psi all round at present & the way they protest they seem soft.

 

too much air makes tires hard and harsh. I prefer soft, so 32 / 33 is fine assuming you set the pressure when tires are cold. As you drive the car the tiire temperature increases and the air pressure rises.

 

That's why it's a good idea to run nitrogen in tyres. One of the only problems with this argument is that people endlessly overstate the benefit. That said you won't find an F1 team or aircraft operator not using nitrogen in their tyres. The greatest benefit of using nitrogen is that it is dry ~ thus leading to more stable tyre pressure with varying temperature.

Ultimately I always set pressure for even wear across the tread, both shoulders & centre.