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

I was wondering something - the handbook for my 4/4 recommends the tyres are inflated to 22psi. Its the same handbook that covers the plus 4 and roadster as well.

Correct me if I'm wrong - but the plus 4 and roadster are quite a bit heavier up front than a 4/4. Can it be right that they all need the same pressure?

The reason for asking - around these parts of deepest Sussex our roads are awful - full of pot holes etc. This causes really bad thuds through the front suspension on occasions - so much so i worry if it'll damage the car. I've been playing and have found running the front at 18psi improves it no end. The steering has remained sharp so i'm guessing Ok to leave at 18psi? Anyone else tried this? Its running its original contis

Thankyou

Hi

I am running the front at 22psi too, and I agree with you. Pot holes everywhere.

Should I also reduce to 18psi ?

18 psi sounds a bit too low to me concerning the pressure. Regarding the 4/4 and her weight I run 25 to 26 psi when driving longer distance on better tarmac. But there is also a difference concerning the choice of tyre.

The OEM Conti has not much grip in the wet and another issue is that this tyre is very stiff at the side wall. A more grippy tyre of same size is eg. the Vredestein T-Trac2 (Other models are also offered, I guess every model has more grip than the Conti). The add on bonus of eg. the T-Trac2 is that it´s tyre wall is much more compliant.

That means that when driving with 25 psi you have more suspension in comparison to the Conti and at the same time a very controlled steering feel. 22 psi with such a tyre should mean to get even more comfort.

I will usually have 22 psi at the front and back, unless I am taking anything heavy in the back seats (mine is a 4 seater) then it is 24 and 26.

22psi all round for me.
I did have them at 18psi originally, but oh that steering, was it heavy...

I now have steering bearings, but I would not go back to 18psi.
Just sounds too low, and flabby.

Don't forget the Roadster & Plus 4 run bigger tyres too, so proportionally the 22psi is fine with the heavier front ends on these cars.

If you're happy running 18psi, then stick with it Andy. Steering response is theoretically slower and the tyre slip angle not as sharp but unless you're into quick motoring you should be fine.

If your tyre wears a bit, then you'll know earlier than most I would guess..!

I checked mine at the weekend and found my N/S/F down to 15psi & it certainly showed through the steering. I thought it was down to needing a grease on the pin, but no. D'oh!

I'd be wary of going any lower or having a big differential between front & rear I think.

I generally run 23 front and 24 reat on my 4/4 sport with Blockley tyres. Seems to handle well & cuts dowb bumps although I run stiffer springs on the front.

Roughly the same on my 4/4 Phil - but then I'm compensating for driver weight (I'll have to pump the tyres up after the service).
Run higher rear pressure if carrying luggage. All on Vredestein TTrac.

If you think trad suspension is hard with bigger profile tyres you should try 45 profiles , the ride is rock 'ard everywhere !

Thanks for the advice .

I expect Heinz is onto something about the contis tough sidewalls - a change to a better / different make would no doubt help and in which case 18psi would likely be too low.


Had a nice long test run tonight on a mixture of roads - including some challenging twisty bits - just to be double sure steering was still sharp. Perhaps my driving style isn't that aggressive but the steering feels sharp with a decent turn in and the handling isn't "flabby". If anything the car feels more planted/solid on the road with the tendency to be a slight bit twitchy at higher speeds now gone. The ride is much improved -totally transformed in fact, whilst the steering isn't stiff either.

Not sure how it'll perform in the wet yet - must check that out before i decide long term but it seems my 4/4, on its original contis, suits 18psi front and around 21.5 rear.

Thanks again,