Taking Davie's advice

[white exec]

Davie (if no-one else) will be pleased to know that I finally said goodbye today to the spare tyre on our XM, when I had a couple of new Michelin Energy Saver+ fitted to the rear end.

I think I made the tyre fitter's day. As he removed the tyre from the spare rim, his face lit up as he announced "1996" - an original Michelin Pilot HX from the factory. It was still mostly unworn, although - to be honest - a little wooden.

Ride on the back end is noticeably softer, having scrapped the 2010 Energy, and switched the 2015 to spare.

Sorry it took so long, Davie. You were right on all counts!

[daviemck2006]

As you k ow Chris, tyres are something I am well versed up on. Personally I don't rate Michelin that much, I think they lose grip and their structure as they age and if you only do a low mileage have usually to be changed due to structural failure long before the tread runs out, which I think then makes them poor value as they are expensive especially changing them with still plenty tread. Does that make sense? It doesn't always follow that more expensive tyres are better. For instance look at continental eco contacts in the size for the 107, 155/65x14. They are well over £50 each off Camskill, the rears on my 107 only 2 years old, and going by mot history only done about 4000 miles. No grip, cracking between the treads, enough to write them off. My preferred tyre for it, uniroyal rain expert 3 £32 each, usually get two new about once a year on the black one, new ones on the back and shift the back to the front. That's with an annual mileage of about 20k, so they do two years, 20k on rear then 20k on front, and have great grip, even in the wet worn right down to the markers at 1.6 mm. In fact the last ones that came off black were illegal, I measured them at 0.9mm then gave Shaun a bollocking lol.

I suppose it's personal preference though, you like your Michelin, and I bet your xm feels better now for 4 new tyres recently, and will be a safer spare with a 2015 part worn rather than the 1996 now plastic bumpy spare lol

[white exec]

Good advice, Davie, on the considerations of deterioration over time vs tread wear - and price.

Good few XM owners have run with tyres other than Michelin, but it seems that the suspension is at its best (maximum comfort and minimal thudding over sudden ridges) with Michelin - originally Pilots, then Primacy and now Energy - probably down to the very supple sidewalls. Even minor over-inflation (by a couple of p.s.i.) can make the ride knobbly and crashy, which seems to bear this out.

What we do know is that on the hydropneumatic suspension, the tyres are very much the first line of sudden impact absorption, with the rest of the system being first-rate at dealing with undulations and handling.

Years ago, Michelins attracted criticism for wet grip (although offering long life) but that has been sorted. What they are, though, is still prone to ageing - likely aggravated by strong sun, which is something I have to be careful with down here.

Cheap they're not. I paid £200 fitted for a pair with you in Inverness last year, and €216 yesterday.

[CitroJim]

I drive so little that I can't remember the last time I replaced a tyre due to pure treadwear... It's always now because of deterioration and that seems to happen faster and faster these days...

A nice little earner for the tyre companies I guess...

[daviemck2006]

I would actually say whatever tyres you buy, be them expensive "premium" brands, cheap crap or part worn, and I have bought part worn and will again, keep an eye on them and look after them. Even if all four are different makes keep them at the correct pressure by checking them regularly, and when they start cracking and degrading, chuck them. A pressure/depth gauge costs very little and takes next to no time to check. My tyres never get down to the wear markers once there it doesn't matter what tyres they are the grip in the wet is reduced. If there's any vibrations or shimmying in your steering check tyres too. It's as possible to be a tyre delaminating and going out of round as it is losing a balance weight or a knackered suspension component. I know most of us on here will know this stuff, but it doesn't hurt to be reminded occasionally. After all, it's only the tyres which connect with the road, and are, in my opinion, the most important part of the car, yet so easy to look after.

[GiveMeABreak]

Even if all four are different makes ..

Personally, I would not mix different tyres on the same axle - different tread patterns can cause the handling characteristics to change. Also different levels of tread wear on part worn tyres across the same axle is not recommended for the same reasons.

This is an interesting read, but there are others sources that say the same:
http://btmauk.com/wp-content/uploads/20 ... mation.pdf

I think there was also an issue with some ESP-equipped vehicles having issues to do with the rolling radius differences when tyres were mixed on the same axle.

[CitroJim]

I check tyre pressures on a weekly basis on all my vehicles, bikes very much included. It's one thing I'm fastidious about...

I use my bike track-pump on the cars... It has a built-in accurate gauge and is just as good for car tyres as it is for bike ones... Just a few strokes top up the tyres a treat...

If any of mine have slow losses of pressure that gets investigated with some urgency...

And needless to say, once they're past their best they're replaced...

[daviemck2006]

I wouldn't mix tyre makes across an axle. Different front and rear I accept. Some vehicles electronic systems don't like a new tyre on one side and a part worn on the other, even the exact same make. And some four wheel drives are very fussy about tyre wear too and can ruin their electronic control systems because of the different rolling radius of new versus part worn tyres. I would say know your own car and do what's appropriate for it. Somewhere the information will be available. For instance when I owned a freelancer it's handbook said always change tyres in pairs and always put the least worn on the back (may of been front I can't remember but you get the jist) or the differences in rolling radius can spool up the diffs causing failure of said diffs.

[Hell Razor5543]

I remember when CitroJim had problems with his XM. It turned out that the tyres were of different sizes (which surprised him!), and this caused all sorts of issues (including with the ABS, IIRC).

[white exec]

Did he go round in circles? . I do remember him saying he never really got on with it....

[CitroJim]

I remember when CitroJim had problems with his XM. It turned out that the tyres were of different sizes (which surprised him!), and this caused all sorts of issues (including with the ABS, IIRC).

Gosh James yes!!! Your memory is better than mine I'd all but forgotten about that!

That was on the V6 XM. It definitely caused a bit of head-scratching and even upset the gearbox!

Did he go round in circles? . I do remember him saying he never really got on with it....

My head did trying to get to the bottom of it Chris!