Rubber on the Front..
Discussion
--------------------------------------------------------------------------shpub said
"19560 said: Don't early Chimaeras come with 205/60R15 tyres? The problem here is that SO-2s and all of the other tyres at the top end of the market only come in a profiles up to 55% so that you cannot have OE and state of the art tyres. Its the same probelm for 350s and S series cars."
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and shpub also replied
"No it isn't as the factory have changed the tyre specs on these cars about 10 times so as long as the size is one of those there is no problem."
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There is a conflict between the manufacturers original specification for some cars and current tyres. You have to decide, one or the other. W is a lower speed rating than Z. Z is the highest speed rating available being the only current rating with no upper limit.
>> Edited by 19560 on Wednesday 16th October 16:34
A warning about the speed rating:-
A few years ago I went to trackday with a mate's TVR 3000M Turbo (originally fitted with V rated tyres cos thats all they had in the bad old days) but for the trackday we fitted my H-rated (then up to 135mph) tyres/wheels.
It wasn't a very hot day and the max speed we probably reached was around 100mph, but at the end of the day my H-rated tyres were knackered. The H-rated tyre was harder than the softer compound Vs, but great chunks (blocks) of tread had come away.
Now my recommendation is as Steve Heath, don't skimp on the tyres, they are your only contact points with the road and the differences in cost that some of you are talking about is only the equivalent to one tank of fuel, so stop being so tight, and think about your life (and other peoples instead)
davidy
A few years ago I went to trackday with a mate's TVR 3000M Turbo (originally fitted with V rated tyres cos thats all they had in the bad old days) but for the trackday we fitted my H-rated (then up to 135mph) tyres/wheels.
It wasn't a very hot day and the max speed we probably reached was around 100mph, but at the end of the day my H-rated tyres were knackered. The H-rated tyre was harder than the softer compound Vs, but great chunks (blocks) of tread had come away.
Now my recommendation is as Steve Heath, don't skimp on the tyres, they are your only contact points with the road and the differences in cost that some of you are talking about is only the equivalent to one tank of fuel, so stop being so tight, and think about your life (and other peoples instead)
davidy
Daviddy..
thanks for the thoughts.. please bear in mind though this isn't a lecture on expenses just whats best for the car.. I don't think anyone is being "tight" on this thread, certainly not me who asked the original question.. in fact I don't think anyones started talking about prices have they..??
Cheers
Matt.
>> Edited to say.. sorry that was a bit
box wasn't it.. don't take it the wrong way 
>> Edited by M@H on Wednesday 16th October 17:16
thanks for the thoughts.. please bear in mind though this isn't a lecture on expenses just whats best for the car.. I don't think anyone is being "tight" on this thread, certainly not me who asked the original question.. in fact I don't think anyones started talking about prices have they..??
Cheers
Matt.
>> Edited to say.. sorry that was a bit
box wasn't it.. don't take it the wrong way >> Edited by M@H on Wednesday 16th October 17:16
As I have four pieces of official TVR paper that came with my car, all giving different tyre sizes (but all ZR rated). I believe that all of them are officially recommended by TVR to be suitable fittings for the car and therefore meet the requirements as Manufacturers OE recommendations. Obviously you don't, so please tell me which one of the four is the official one. 
As for the W and Z rating. Look at the small print. The Z rating has its upper limit specified by the manufacturer's recommendations which can be this is the max or you need to run with this load or pressure. It does not mean that there is no upper limit.
It is an older definition that was not well defined when 200 mph supercars started coming out. In the same way that VR ratings got superceeded. Hence the W and Y ratings that define that maximum limit rather than leave it to guesswork. A lot of ZR rated tyres are now being rerated as ZR+W or ZR+Y. This has happened/happening with the Bridgestone. Their current product file rates them as W or Y whereas the ones sitting in my garage are marked ZR. The TVR sizes are Y rated BTW.
The original question was what is this W rating. Well it means that rather than the manufacturer decide if the tyre is suitable for a certain speed, the tyre has been rated as meeting that upper speed and that is at least an equivalent, or in my view, better rating and therefore nothing to worry about.
If you want to argue that ZR rating means no higher limit and that it is the better spec then fine.
>> Edited by shpub on Wednesday 16th October 18:21
>> Edited by shpub on Wednesday 16th October 18:21
As for the W and Z rating. Look at the small print. The Z rating has its upper limit specified by the manufacturer's recommendations which can be this is the max or you need to run with this load or pressure. It does not mean that there is no upper limit.
It is an older definition that was not well defined when 200 mph supercars started coming out. In the same way that VR ratings got superceeded. Hence the W and Y ratings that define that maximum limit rather than leave it to guesswork. A lot of ZR rated tyres are now being rerated as ZR+W or ZR+Y. This has happened/happening with the Bridgestone. Their current product file rates them as W or Y whereas the ones sitting in my garage are marked ZR. The TVR sizes are Y rated BTW.
The original question was what is this W rating. Well it means that rather than the manufacturer decide if the tyre is suitable for a certain speed, the tyre has been rated as meeting that upper speed and that is at least an equivalent, or in my view, better rating and therefore nothing to worry about.
If you want to argue that ZR rating means no higher limit and that it is the better spec then fine.
>> Edited by shpub on Wednesday 16th October 18:21
>> Edited by shpub on Wednesday 16th October 18:21
Two things strike me here: firstly since we are talking about front tyres what are the four different tyre sizes fitted to the front and secondly only one size can have been MANUFACTURERS ORIGINAL EQUIPMENT to your car by definiton - the others must all be other options ( presumably thought more suitable over time and probably superior developments ). This is the point that I have been promoting - fit the best possible tyres to your car, not necessarily exactly MOE, upgrade where possible.
19560 said: Two things strike me here: firstly since we are talking about front tyres what are the four different tyre sizes fitted to the front and secondly only one size can have been MANUFACTURERS ORIGINAL EQUIPMENT to your car by definiton - the others must all be other options ( presumably thought more suitable over time and probably superior developments ). This is the point that I have been promoting - fit the best possible tyres to your car, not necessarily exactly MOE, upgrade where possible.
Actually the case I have it was rears and they ranged from 225/50, 225/55, 235/50 and 245/45. The car came with 245/50.
For the fronts there have been 205/60, 205/55, 215/50, 225/55, 225/50 OTTOMH
I would agree that fitting the latest combination for a PAS car of 225/50 front and 245/45 rear is the best. They were MOE on some cars but not all and became the only viable sizes when Bridgestone stopped making some of the others. The point is that we have been making from different angles is that all of these have been fitted by TVR and therefore are approved options/OEM or whatever you want to call it. They are all ZR rating. As soon as you change to a different size or rating then you are in the modified zone. For most people this means modifyiing while retaining a similar overall size and speed rating. The speed rating is important - it is illegal and a fineable offence to run a lower speed rating than that defined by the manufacturer in some EU countries already - and it is possible that this legislation will come to the Uk and remove a lot of the grayness we have been discussing.
I think we agree.
I agree that
Just got an e mail back from TOYO on the matter:
Andrew.
As you state we only produce this size in "V" (max speed 149.1 mph). From a legal point of view it is permisable to fit this tyre because in the UK the
maximum speed limit is "70 mph". Insurance companies might take a different veiw. Toyo are currently working with TVR to remedy the situation and should
have a soloution in the near future.
Regards
Alan Meaker
Technical Engineer
I'm disinclined to use the two new ones I have lying about until (or if) they have something more definitive to say on this.
So we all agree then?
Andrew.
As you state we only produce this size in "V" (max speed 149.1 mph). From a legal point of view it is permisable to fit this tyre because in the UK the
maximum speed limit is "70 mph". Insurance companies might take a different veiw. Toyo are currently working with TVR to remedy the situation and should
have a soloution in the near future.
Regards
Alan Meaker
Technical Engineer
I'm disinclined to use the two new ones I have lying about until (or if) they have something more definitive to say on this.
So we all agree then?
Gone on eBay today, full set of Chimaera Wheels with 7mm tread SO2's, Bid away guys
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=1778674720
davidy
PS M@H no offence taken, I wasn't having a good day and I needed to lie down in a dark room rather than be terse on PH!!
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=1778674720
davidy
PS M@H no offence taken, I wasn't having a good day and I needed to lie down in a dark room rather than be terse on PH!!
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