Tyre pressure query

Associate
Joined
25 Mar 2008
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Hopefully I will find some answers here from the motoring experts. I recently replaced my tires (205/45 R16) with 205/55 R16 as the lower profile tyres where very harsh on the road coupled with the sports suspension. The country road I live on is very rough and hilly so it's not the most pleasurable journey every time down and up the road so I decided to get something a bit more forgiving.

That aside, I am led to ask for some advice. I am wanting to know if there is any recommendation as to what pressure I should have in my tires. The sticker on the fuel cap tells me the front should be 30 psi and the rear 28/29. This I would assume is based on tyres meeting the original specification of the car. Does a higher profile tyre have require anything different?

To make it more awkward to decide my haynes manual is telling me 29 psi for the front and 32 psi for the rear. Does 2-3 psi either way make much of a difference?
 
Soldato
Joined
21 Oct 2002
Posts
21,453
If I dont know or cant easily find what pressures they should be, I whack 32 in the fronts and 35 in the rears.

Its not scientific, its not based on any meaningful research or testing.

But nothing has ever broken, and Ive not wrecked any tyres or suspension components either.

Most of the time you can find out what they should be.
 
Last edited:
Soldato
Joined
25 May 2008
Posts
3,738
Location
North Wales
You tend to run more in the fronts due to it having more weight over it with the engine, it'd stick to around what the recommended pressures are and go from there. I tend to adjust the pressures a bit whenever i get a new car to find a balance i'm happy with. Keep checking the wear on the tyres and as long as they're wearing evenly across the whole tyre you should be fine.

On a side note you'll have to be aware that your speedo will be reading quite a bit out now you've got bigger tyres on your car as they've almost 7% bigger in rolling radius where the maximum recommended is usually 2.5% bigger.
 
Associate
OP
Joined
25 Mar 2008
Posts
784
Location
Northern Ireland
Thanks for the reply guys! I did think the car seemed to be travelling faster at the same level on the speedo so I'll need to check that against my sat nav. The sat nav would usually have read 3-4 mph lower than the speedo, so it will be interesting to see what it reads now. Is there any way to calibrate the speedo to the tyres or is it just a case of being more cautious?

As for the psi I'll stick to the recommended and see how it's going after a month or two. :)
 
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