XJS tyres

[Carole Simpson-Hadley]

Morning all (or afternoon or evening, or "what are you doing up at this time of night?!")

Reference an earlier query which we raised about XJS tyres.........our newly acquired XJS sits on OE Pirelli P600 tyres, sized at 235/60 R15.   These were the tyre originally specified by Jaguar and went on to end of production.    They are now not always easily available, no longer produced, and run out at silly prices.......anything from £214 to almost £500 per tyre.  

We were advised by XJS Reborn that Falken ZE914 225/60 R15 were a far superior alternative, being a more modern assymetric tread pattern which actually puts more rubber on the road.

We were a little concerned at the variation in rolling diameter (as the Falkens have a sidewall depth of 60% of 225mm (hence 225/60) whilst the Pirellis have 60% of 235); effect on speedo accuracy, auto change speeds and the cosmetic aspect of how they fill the wheel arches.       **The formula for calculating rolling diameter variation puts the resulting figure (Falken ZE914 v Pirelli P600) at minus 1.9%.....this is within the acceptable variation of +/-2% and so all is well.   The variation used to be +/-3% but that altered a while ago.

Glad to report that the Falkens (having viewed them on a similar XJS) actually look better than the Pirellis, and at a unit price of around £95-100 (depending on where you buy) are far kinder to the little man who lives in the cupboard (aka the bank manager).

With reference to the 225/60, these are also available in Continental.   235/60, as per the OE Pirellis, ARE available in budget ranges such as Saferich and the like, but they are not for us.  Beware, also, of a tyre supplier who says there are other alternatives, as these are usually van tyres, which would fit, but would not have the correct speed rating and, therefore, could void any insurance claim.  

Reference our XJS, all the Pirelli OE tyres have plenty of tread and no visible cracking etc; however, examination of the date codes revealed that three of the tyres had 3 digit date codes which puts them at pre-2000.  The O/S/R was, in fact, showing 242 which means week 24 1992 i.e. sometime in June 1992; our XJS left the line in September 1992 so that suggests that that tyre may have been the original spare which found its way onto the road possibly during the recommissioning, after 8 years in controlled storage, in 2017.  We are not about to run around on 18+ year old rubber, so a set of 5 Falkens it is.  

Hopefully, this may help anyone who, similarly, finds that their older style tyres, whilst inferior old-style products, are also now about to break the bank.

We should like to say "back to the Carnauba", but the weather is, well, wet wet and wet again....again!

Never mind, happy growling