Alloy wheels tyre pressure

[idthomas]

I have a mk IV 1300 spitfire with 5.5x13 alloys with 175-70-13 tyres. 

What tyre pressure should I be using?

IanDT

[Pete Lewis]

 not got the manuals in front of me right now but use what they say for radials

Size of tyre and wheel has no effect over the  presure devised to make a safe foot print (pressure = load x area ) 

Modern radials may suit an extra few lbs,  but keep the front rear balance the same or you affect the steering 

Pete

 

[dave.vitesse]

I have the standard pressure as 21lb front and 26lb rear for 145-80-13. MkIV Spitfire.

Dave

[idthomas]

OK. .. same as original narrower steel wheels .. thanks

[AidanT]

There's been quite a few threads on this subject. Some say use the standard pressures some say increase them for modern radials  I am testing using 26 and 28 rear on 175/70 13 tyres  So far the tread has had even wear over the tyre and steering is not too stif

 

Aidan

 

[JohnD]

It's not the wheel that determines the tyre pressure, it's the tyre! (Doh!)

All tyre manufacturers will recommend a pressure, but it also depends on the way you drive that tyre.    Checking on tyre wear with a tread depth gauge regularly will show up insufficient or excess pressure, and a need to adjust camber.

See: https://www.national.co.uk/information/tyre-maintenance

[dave.vitesse]

I agree the standard pressures are a start point.

Dave

[hugh]

Spent may days playing with tyre pressures on our turbo spitfire (220bhp) with 195/50/15 tyres and alloy wheels eventually settled on 24 in the front and 28 in the rears as the best for even wear and grip, as said treat the recommended pressures as a starting point, but people are right about modern tyres needing a little more pressure