255/45/38 Tyre Pressures (wearing in middle)

[Mr.Blue]

Hi Guys,

I have a T6.1 Kombi with Koni Coil-overs and 18"x8J wheels. In general the van carries little weight other than 4 passengers. The rear tyres are worn now and due to be replaced, but they are wearing heavily in the centre of the tyre. Originally I was running 44 psi in the tyres, but the previous set were heavily worn in the centre, so for this set, I reduced the pressure to 36 psi, but they are still wearing in the centre of the tyre. Any idea what pressures to run in the tyres to prevent this? I know for a Cali it recommends 48 psi all around, but this will just cause even more wear in the centre. Any advice is much appreciated.

 

[GOT THE BUG]

Generally when you have excessive wear in the center it's a case of over inflation of the tyre, which seems you know this as you ran less pressure with the same problem, then i can think of two things, still over inflated, check tyre recommendation for pressure or possible wheel alignment??

 

[Mr.Blue]

@GOT THE BUG thanks for your reply. I don't think its alignment as the wear is equal across the middle of the tyre. Often if its alignment its more randomised. It shows all signs of over inflation, but going lower than 36psi on a T32 just doesn't seem right.

 

[PaulR83]

I had the exact same on my T32 with those tyres and 44psi. Tyres lasted 8k. Fronts always looked low so wouldn't want to drop pressure any more. Van lowered too and correctly aligned. Never found an answer. Now running 235/55/18 at 41psi and hoping it doesn't happen again.

 

[Mr.Blue]

I had the exact same on my T32 with those tyres and 44psi. Tyres lasted 8k. Fronts always looked low so wouldn't want to drop pressure any more. Van lowered too and correctly aligned. Never found an answer. Now running 235/55/18 at 41psi and hoping it doesn't happen again.

Cheers @PaulR83 its nice to know its not just my setup then! I am running 255/45/18. How are you finding the 55 profile, does it make the ride any softer over the 45?

 

[PaulR83]

I haven't noticed and difference to be honest. Still harsh and crashy. My be because I'm too low in the B14 komforts. Speedo correct to GPS now though.

 

[Kind of Blue]

If tyres sizes load rating and so on are changed from the factory sizes then the suggested ideal pressures may need revising. Check on a tyre comparison site where the original fit details are inserted and then the new tyre details and a new recommended pressure will be suggested.

Tyres showing ware patterns in various places often suggests incorrect pressures and so central ware may then suggest over inflation but it is general guide. Wheel and suspension geometry ought to be checked as it can change over time or smashing over potholes.