Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Tyre advice

Guys,

I have recently purchased an '88 4/4. I suspect the tyres are the originals. (DOT code is 427) with less than 20k miles on them they are far from worn, but I suspect the compound is not at its best. The size is 165SR15 (uniroyal rallaye). I suspect that the tyres predate the current sizing style - theres no aspect ratio!- What size tyres do i need and are there any recommended brands?
edit - I'm on painted wires btw

thanks

Hi sawman, size sounds right, a/r is 80 but tyre size pre-dates low profiles so it is often not stated. Current 4/4 Sport uses 165/80 15 Continental and they are more than adequate, buy your self a new set, I have seen them on web tyre dealers as low as £40/tyre.

On my former 4/4 4-seater (1991) I had Continental 165/80 15 and they performed well and lasted for70000kms.
On my new 4/4 Sport the same tyres are mounted.
The factory recommends 1.3 bar for the 1991 4/4 and 1.5 bar for the 4/4 Sport; this is quite low but provides a softer ride (tyre inflation of better said lack of tyre inflation is part of the Morgan suspension!)
I keep the tyre pressure at 1.8 bar which is better for roadholding and tyre life, but gives a harder ride.
D'herde Bart

I believe that current recommendations are to change tyres every 5-6 years regardless of wear rate to protect against deterioration of the compound.

I'd agree with Robert. When I bought my 4/4 it had done very little mileage from new ( In fact, that was the reason why I almost didn't buy the car!) The result was that all of the tyres (factory -fitted Avons) were almost like new in terms of tread depth etc. The spare had never been on the car.

However, what quickly became very obvious was that the sidewalls were suspect- not least becuase they ahd become very hard.

I tend to be fairly anal about details like this, so I did some fairly extensive research and all the info confirms that 5 years is a maximum in terms of tyre life because of the degradation caused by light.

I changed the lot and am now running Yokohamas. The ride, cornering and general 'stickability' are now all a heck of a lot better

If there's no little triangle after those numbers then the tyres were made in the 42nd week of 1987 (if there is then they were made in the 42nd week of 1997). Either way you would be well advised to change the tyres.

As to make and type, it really depends what you want from your tyres and what kind of driving you like - but anything will give you better and safer handling than those.

As Easter says, the aspect ratio in older radials is assumed to be 80 when not stated.

There doesn't seem to be much choice in the 165/80R15 category. Looks like I'll be getting some firestone f560, as that it all that came up on numerous searches

I don't know where you're located but if it is at all practical ( and you haven't tried them already,)

try:

http://www.longstonetyres.co.uk/

Longstone is not far from me, and since they are Borrani Agents I'm optimistic that they can balance wires properly. So when I'm ready I might just call in.

The sprinters would recommend either:

185/55/15 Toyo Proxies T1R's

Lower and wider (which I appreciate is not quite the trad look) but don't arf stick well.

Alternatively take you pick of higher profile tyres... interestingly there is a List 1B Vintage tyre which you can get as well.. (ie. old vintage racing tyre.. which is very sticky)

Avon CR6 ZZ 70 Section tyres would be the ones to run.