Runflat Tyre wear ???

[Scooby_Doo]

My W205 has 19" AMG alloys fitted with Continental runflats. The sticker on the fuel flap recommends 250kpa front and back 3 up with luggage. I'm on my own in the car most of the time so I run them with 215kpa all round which softens the ride considerably, I've just checked the front tyres and I've got 6mm of tread at the sides and 4mm in the middle which is normally a sign of overinflation . Is this a runflat thing or should I drop the pressure even further ??

 

[Bellow]

There's a recent thread (past few months) on this topic. Worth a read - it will answer your question.

 

[Scooby_Doo]

Re-read that thread so I'll probably drop the pressures again.

 

[John]

Over-inflation is a strong contender for middle tyre wear...

 

[Bellow]

Re-read that thread so I'll probably drop the pressures again.

IIRC from the other thread the only thing to watch for is the centrifugal fling at speed mentioned by WIM. I suspect he posted that as a caveat for thus who indulge in big big speeds. At more moderate speeds there'd be more latitude for lowering pressures. Go too far and the handling will deteriorate anyway so unlikely you'd set them at something stupid.

 

[Scooby_Doo]

The reason for the thread was to try and get any cons of dropping the pressure , I'll have to take the hob nailed boot off my right foot.

 

[John]

The reason for the thread was to try and get any cons of dropping the pressure , I'll have to take the hob nailed boot off my right foot.

If you drop them too much, you'll start wearing the shoulders. I would think 34psi would work for you.

 

[Scooby_Doo]

MB recommend 36 psi , I'm currently running them at 33 psi and still wearing in the middle.

 

[whitenemesis]

What do tyre manufacturer's websites recommend? These days MB figures tend to be high to get best mpg.

 

[John]

I had something similar with my 1997 M3 Evo back in 2000... no matter what I set the rears to, they wore most in the middle.

I put it down to my, ahem, style of driving.

Not sure if you are doing the same but 33psi sounds quite low to me to still cause an issue.

I'm wondering if suspension / geometry-related.

 

[Scooby_Doo]

Just to clarify , it's the fronts I'm having the problem with. The rears with the same pressure are wearing evenly across the tread.
Car's an 18 plate with 9500 on the clock.

 

[ToeKnee]

Have you got a IR thermometer? If so check the temp of the tyres in several places across the width after a good run, you'll soon see if the pressures are correct if part of the tyre is cooler.