Talk Morgan Forums Morgan Sports Cars Morgan Plus Four, Supersport & Plus Six (CX & CXV Generation Vehicles) Cx plus four tyre pressures

Hi, seen lots of threads about tyre pressure,s but none about the cx plusfour.
I'm wondering what anyonr else uses as the handbook pressures seem high compared with the other
lightweight cars I've had

I'd expect something around 22psi but the handbook recommends 28

Thoughts?

i use 28. The trads have 22 as the tyres wall flex is part of the suspenion. The CX has a modern suspension relying less on tyre walls.

Do you not find it a bit bouncy and firm (for want of a better description)

Yes - the ride is certainly very firm on my 2025 Plus Four with Nitron suspension (standard settings) and the tyres at 28 psi. Can be a bit jarring on some roads, but doesn't seem to bounce.

It is fine for me

I expect the greater travel and compliance from modern wishbone suspension more than makes up for the increased tyre pressures.

It does the ride is smoother than a trad

This may be oversimplifying, but what does the Plus Four weigh (as driven) in pounds, divide that by the tyre pressure and that is the footprint that the tyres need to have in contact with the road to make the equation balance. Reduce the pressure and the footprint has to increase to keep the equation balanced. Increase the footprint beyond what the designers (both car and tyre) intended and the performance of both will be compromised.

Stick to what MMC recommend IMHO.