tyre pressure question

[205man]

does any have a definitive answer to what pressure we should run a 2.8qs saloon (with auto box), running 225x40x18s ?

i couldnt get straight answet out of my local tyre company, and eveyone seems to have their own opinion and they vary wildly

alan

 

[aragorn]

The TQS runs 36 front and 34 rear on 225/45r17, and the S4 is 36 all round on the same size, so thats a fair starting point.

 

[jcb]

Personal choice as much as recommendation.
If you dont like how it feels change it till you do
I run lower front pressure by 3-4psi 33 - 36 as it counteracts the understeer already dialled into the chassis set up.
I also tend to have a lot of crap in the boot, like 200kg of sand and cement the other day

 

[SonicDeathmonkey]

Dude, you drive around with 200Kg in the boot? Thats insane. It's lie constantly having two large people in the car.

What impact does running higher pressure have on MPG?

 

[aragorn]

Reduces it by a little.

I tend to stick an extra 2-3psi in when im heading on a long trip up the motorway, as it usually gives an extra mpg or two.

 

[jcb]

Dude, you drive around with 200Kg in the boot? Thats insane. It's lie constantly having two large people in the car.

Ha, thats nothing, had two sofas on the roof once! trip to IKEA to pick up a big flatpacked wardrobe and it was only after when I started doing the mental maths from the weghts on the boxes that I realised i had 500kg in the car, 300 of which was on the roof!!
its a working vehicle and will die working....