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MG ZR ZS ZT Technical - Tyres For 18' ZT Wheels ZT260

As we now run classics, like it or not, we now have to rely on this network and the MG owners clubs for the information which allows us to satisfactorily run our new classics.

I have to say that one piece of info I received from Roger Parker of MGOC has transformed the way in which my ZT260 runs.
In the dying days of MGR the development team were working on the stillborn ZT385 and used a ZT260 mule on which the experiments were taking place. The ZT260 as a big fast car and when pushed to the limits will devour tyres with aplomb.

The standard ZT260 fit is 225/45/R18 usually Contis. The development team were using 245/45/R18s on the ZT385.

My ZT260 munched through its original 225 rear tyres in less than 8,000 miles (burp) OK there was some post run in ...let's call it spirited driving. I replaced these with some dirt cheap 245/40/R18s NS-2 by Nankang, thinking that if the car is going to eat them up might as well fit sacrificial rubber on it, and the 245 will have a bigger contact area.

What a difference these tryes made. The old Contis had sent some nasty messages to me from the rear on occassions, particulalry as they appoached Kojak status. And they never felt completely right.

I can tell you that a combination of 225s at the front and 245s at the back works brilliantly, just perfect! No silly wobbles, more traction, no scary midcorner dizziness.
Furthermore the 245s have already seen more miles than the originals AND they look fine many more miles in them, maybe twice as many as the Contis

The Nankangs are a harder rubber and whilst some say oeer about the traction of these in the wet it hasnt turned out to be true. as mentioned I think traction is better, also because the tread lasts longer!

I beleive for the ZT260 that the original spec tyres may have been too soft and too narrow for optimal performance. So I recommend that you try it for yourself, obviously being as sensible with the rear in the wet as you should be.
Neil

If nothing else, the slightly extra tyre bead helps stave off the nasty kerbs and keeps the alloys looking good. I have had Maxxis 245/40 18 all round on my ZT and like you say, they are half the price, seem to be lasting longer and haven't affected handling at all, although I think the original Michelins (of which I went through 3 sets before these) were a little better in the wet.

There are some very tight clearances in the arches but as yet no sign of rubbing.

However Nic Faasi berated me for changing from the factory suspension tuned tyre size, and rightly pointed out that it could invalidate the insurance as they were not factory homologated.

I am talking about a FWD ZT, though.
Martin ZT

What we as enthusiasts often fail to appreciate is how much work the manufacturers put in coming up with the best tyre options and sizes to fine tune handling characteristics.

I'd imagine that the development and homologation engineers probably do get erked when we come along and change all the sizes, use different tyre brands and then say how much better the car feels! LOL

Mind you, as enthusiasts, we often have no bias with regard to brand preference, so I think that there is no harm in sharing information like this - especially where perceived performance is within 9/10ths of the original for a much reduced cost...

I guess we can only ever provide subjective analysis - performing objective analysis requires specialist equipment and circuit facilities. Now that would be fun! :o)
Rob Bell

It cant be too upsetting for the development engineers as they were using 245/40/R18s on their test mules.

Neil

Not on FWDs they weren't Neil :o)
Rob Bell

I have always been at pains to point out that th echange was done on a cost basis rather than a gain in handling. For my driving at well under 10/10ths 99% of the time, I haven't felt a noticeable change to the handling, or indeed the ride comfort. But I would like to know why they chose the most obscure size tyre to productionise the car with when there are loads more options in omore common sizes at much better prices. Was it the constraints of the wheel arch and clearance?
Martin ZT

probably to do with bm development and using 225/45/18 on the m3
william

I'll ask the engineers! I am sure that there is a reason, but clearly choosing a popular size was not a priority.
Rob Bell

Ask Rog, that's where I got the info

Neil

This thread was discussed between 07/06/2006 and 12/06/2006

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