Recommended radial tyre pressure for Herald

[JULIA]

I have recently bought a Herald 1200 (with 13/60 engine). It has radial tyres 155/80 R 13 79T. Could someone let me know correct pressure for these tyres please? Thanks, Julia member 24076

[RobPearce]

There are load sorts of reasons, but 30psi

[JohnD]

"Correct" ture pressure is dependent on your driving style, state of your roads etc.

Start at 30 by all means but monitor tyre wear with a depth gauge.    Quicker wear in the middle of he tread = too high pressure.

This is a slow method!  Using an infrared temperature 'gun' on the tread after a run and excess heat in the middle shows excess pressure.   But be quick!  The tread cools down soon after stopping!

John

[Rosbif]

2 hours ago, JohnD said:

Using an infrared temperature 'gun' on the tread after a run and excess heat in the middle shows excess pressure.   

I've never thought of that way to test. I might give it a try. At least it gives me a reason for giving the car a good run out 😁

[JohnD]

The 'F1' way would be to use a tyre pyrometer, that has a needle probe to be pushed into the tread, to read the temp just below the surface.   The IR gun only reads the actual surface, that radiates heat fast.

With the pyrometer, this may be done easily by one person, going around the car, taking temps of inner shoulder, mid-tread, and outer shoulder, and writing them down.     This is the ideal, but a pyrometer is four times the cost of an IR gun!      To do it with the IR gun demands practise, a slick operator who will start as soon as the car stops and an assistant to write down the numbers - preferably on a pre-printed table.

BUT and IMHO, useful numbers can be obtained, even by the solo driver who leaps out to take the temps themselves!

John

Edited June 29 by JohnD