Hi - well I'm not a magician and no I don't have the panacea for all of our tyre problems. The comments I had for Brian I thought may be useful because I know him and he knows my car.
There has been much more technical and informative stuff provided in other threads by many more knowlegeable people than me - and thank you to them - the various points to be considered could fill a book (and do!)
My approach is much simpler really and none of it is particularly earth shattering - I simply wanted to establish what tyres are likely to give the 'best' performance for my car for sprints and hillclimbs and, as you know, this is mostly subjective and must include allowances for other things - general road use / wear / mileage.
Anyway, I have been considering upgrading my wheels (fancied some slightly lighter alloys) and thought that 13 inch may be best / not sure, but list 1A is an important point. I looked @ Toyo - harder compound - good in wet, Yokos = OK / good reputation
Bridgestone = best with 720 for 13 in but these have higher profile than 15 in SO2 which means flex. Can be buffed same as SO2 to get down to softer compound. BMTR advise (in their opinion) that 15in probably best - this is based on the bhp of my car - they think that on 13in wheels I will have difficulty in putting power down - lighting up the tyres too much.
But, Nick Potter runs 13 inch Toyo Proxes on his car - which is a very similar spec to mine - and our times are generally very close. I don't think either of us is consistent enough yet to really tell which tyres are 'best'. He was quicker at MIRA and I was quicker at Curborough - and that could have been the gearing differences - I'm happy with my gearing at C/boro but couldn't maximise the grunt through the long left hander at MIRA.
I used the SO2 in 2000 and my times improved. Interestingly, they improved more by the end of the season as a result of me becoming more familiar with the car than they did at the beginning. Which takes me back to a previous email and the fact that actually receiving tuition and then using the car will make the biggest difference to 'our' times.
I have heard it said that, as a guide, 'good' tyres can make half to one second difference per 'lap' but that really is irrelevant until you're getting the best from the car. I don't think that I am yet so, after some deliberation I am sticking with the 15in SO2s that I used last year = they were good and gave precise handling (mostly!). I didn't change anything else on my car - I went from 13in wheels (sporting horrible Dunlop SP2000 Sport Tyres) to the 15in wheels - no changes to camber angle / ride height / roll bars (or any of those other technical thingies!).
Finally, I saw the suggestion of a tyre test day - this is nice idea but I think that for most of us mere mortals it will only help to confuse us. I have found a big difference from varying the tyre pressures - I know this is obvious but it really has surprised me at what a difference it makes. I say this because I could easily spend half a day at Curborough playing with just my set of tyres (sad I know but humour me!).
Sorry if this is long and irrelevant to you!
STEVE