Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Tyre Pressure

Hi
I have a 1990 +4 4seater 2L Rover. The tyres are AVON ZV5's 195/60 R 15. My question is, what should the tyre pressure be ? The previous owner ran almost flat tyres whilst trying to improve the ride. I have uprated both the front and rear suspension which has improved the ride (mostly touring mileage) however the steering appears to be very stiff, in my opinion due to tyres with very little air. Does anyone out there have a general guide as to what the right pressure might be?
Many thanks

I have it on expert authority (SSL) that 22psi is plenty for the front.
My first question would be how old are the tyres? Many people find a vast difference with new rubber, so if they are 8 years old or so, worth changing anyway as rubber hardens over time.
Also, exactly what do you mean by uprating the suspension??
One further thought, with the front jacked up, can you spin the steering wheel with one finger in the steering wheel spokes?

Thanks Deejay
The tyres are around 5-8 years old, suspension by SSL and telescopic dampers on the rear. the present set up is 12 for the front and 15 on the rear which I think is bizarre. I'm in the process of pumping them up now.

Hi Again at 22 it was ok, unfortunately I couldn't give it much speed due to where we live, mainly lanes with lots of blind turns. I've gone up to 25 all round an it's a remarkable change in steering, hopefully tomorrow I'll open it up on a local road with lots of fast bends.

Good news; those pressures were crazy!
You can check exact date of tyres from a code moulded in on the sidewall; look for a 4 digit number, usually in a little depression near the rim. The first 2 digits are the week number and the second 2 are the year.
Don’t expect you need to be reminded about greasing the suspension regularly too. I do mine every 500 miles.

Change them if over 5 - 6 years old

I changed mine after 8 years. Probably left the change a little too long but I don’t drive very fast these days. 22psi with SSL at the front seams about right from my experience.
Bob.

Be very careful with those tyres, at that age and running below proper pressure will have put a lot of bending stress into the sidewalls as they rotate

As John says above, change them...what price do you put on safety ?

I run my 4/4 tyres at 23psi all round, and feel that this gives the best combination of sidewalk flexibility and steering lightness. An old set of Avons that have been run at less than 15psi should definitely be replaced as the sidewalls will have been overstressed in my view.

I have Vredestein Sprint Classics on my car. The rears are 5 years old, the fronts are 9 years old. the car lives in a dark garage most of the time, so they are not exposed to much in the way of UV degradation. There is loads of tread left on each tyre - 4mm or so. There are no visible signs of ageing or deformation. I took it out for a good thrash round last week, and I could detect no difference in handling or road holding from that which I'm used to. I could get the tyres to chirp when I wanted to, and they clung on just as tight as I wanted them to when cornering.

For a heavy powerful car with upwards of 200bhp that is driven hard especially on track days, then yes, changing tyres every 5 or 6 years is probably wise. But for a 4/4 or +4 used for summer cruising and touring, not so much in my view.

I will probably put a fresh pair on the rears next winter and move the existing rears to the front, but I am not going to stress over driving around on old tyres this summer. Yes, it's a risk, but as long as the tyres have been looked after and regularly inspected, I don't believe it's _that_ much of a risk. With a car that only weighs 850Kg or so, they are far less heavily loaded than their design capacity.

In my 2003 Zetec engined 4/4 I run 21/23 when loaded and 19/21 unloaded.
I use Continental tyres and change them every 6 or 7 years.
Bud
4/4 - Stanley