mx5 Tyre Wear

[CliveAC]

I have a Sept 2014 MX5 2.0 Sport NavTech from new. After 4000 miles the depths across the front tyres are 5, 8, 5 mms from one side, centre, to the other, and the rear both 5, 7, 5. The tyres are Potenzas 205/45R17 84W. The recommended pressure is 29 which I use. This seems strange wear after such a low mileage. Is this my driving? My dealer suggests over-inflating. Any other ideas?
I owned a 1999 MX5 for 15 years. I think the tyres were 195/55. I achieved excellent "uniform" wear on these.

[MX-5 Lazza]

Do you have a tyre pressure gauge or are you relying on the gauge on a pump for pressures? I've always found pump gauges to be very inaccurate and always use a digital pressure gauge. Worth a check. That tyre wear does sound like a case of under-inflation.

[Richyvrlimited]

1mm difference.

seriously?

[MX-5 Lazza]

Get your calculator out Richy - 5-8-5 accross a tread is 3mm difference. It's the uneven wear across a tread he is asking about, not across axles

[CliveAC]

MX-5 Lazza said:

Do you have a tyre pressure gauge or are you relying on the gauge on a pump for pressures? I've always found pump gauges to be very inaccurate and always use a digital pressure gauge. Worth a check. That tyre wear does sound like a case of under-inflation.

I have my own simple gauges that have been consistent over the years.

[AdamR172]

Sounds like under-inflation to me, too...

[MX-5 Lazza]

Maybe it does just need a few psi more pressure then. Bridgestones tend to have very stiff side-walls so maybe that has something to do with it. I don't like over-inflation much though as it does reduce grip, especially on wet roads. If it's not using the tyres evenly across the tread though maybe that is less of an issue.

[CliveAC]

Thanks for the feedback. Other sources also suggest over-inflating a little. I am going to run them at 30 front and 31 rear.