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Tyre pressures for radials

Posted: Tue Aug 07, 2007 7:35 pm
by jollyroger
Hi,
Can anyone tell me if the tyre presuures for radials are the same as for crossplies?
I have 155 x 14 Firestone radials fitted all round. What are the correct pressure for front and back?

Thanks

Rog

Posted: Tue Aug 07, 2007 10:53 pm
by rayofleamington
Hi Rog,
hmm - 155's. If you have them fitted on saloon 3.5" rims, then it's anyone's guess really - hopefully someone who has used these for many 10's of thousands of miles may be able to give a better answer.
Your driving style will have a big influence to the wear pattern as the tyres will roll around a lot more than narrower ones. Heavy cornering will wear the outer edges and lots of straight road miles will wear the centre of the tread. You can adjust pressures down to minimise wear in the centre of the tread, however this will increase the tyre roll on hard cornering.

145 is the maximum recommended width of tyre for the saloon rims (by the guys who produce tyres) - for 145's, I'd say 26/24 for running unloaded gives even wear, but it can vary slightly depending on which brand of tyre they are, and also how hard you drive. If running with passengers and weight in the boot it helps to increase the rear pressures to 26 or maybe 28.

Posted: Wed Aug 08, 2007 8:35 am
by dunketh
I run mine 30 all round. I use 155 tyres on standard 'late' saloon rims and anything less than this makes them baloon out at the bottom.
Even with them at 30psi they're by no means 'rock hard' but I darent go any higher as the tyre-to-rim seal isnt the best in the world! :lol:

Posted: Wed Aug 08, 2007 12:21 pm
by Stig
I use 28psi all round, with any less the handling is pretty poor. Not tried a higher pressure though. Yes, they are too wide for standard rims but at the time I couldn't get 145s so unless I change all 5 at once I'm stuck with them.

Posted: Wed Aug 08, 2007 7:52 pm
by jollyroger
Thanks for the info guys.
The tyres were on the car when I bought it and don't plan to change them either. I'll try them at 30 and see how they run.

If anyone else runs them please let me know.

Thanks
Roge

Posted: Thu Aug 09, 2007 10:08 am
by Rob_Jennings
used to run 155 on 14 rims, although im a bit mix and match at the moment (14 155 on front 13 165 wide on rear... long story)

generally with 155 tyres 30 is about right much lower and its like riding a space hopper

Posted: Thu Aug 09, 2007 8:09 pm
by bmcecosse
Yes 30 psi all round - rears to 36 with a load on (mine is a Traveller).