Car - Atom 3.5 245BHP
Driver - An Atom Cup racer and Atom owner since 2003(?), currently enjoying his 5th Atom!
After a damp morning on Atom Cup spec wets, the dry tyre test could begin. The weather was cool but clear, and dry. All tyres were 195/50R15 front, 225/45R16 rear.
1st up (and 'control' tyre) was Yokohama A048-R soft front, medium rear- the car was (as we all know already) balanced, good front and rear end grip, though as ever the rears could be overheated if provoked.
2nd up Kumho V70A supersoft front and soft rear - initially from cold these were superb, and indeed the front end continued to be superb, better turn in, more stable under braking, with good rear end traction and feel. Problem - it turns out that a soft rear is too soft, the car overheated the rear tyres halfway through a 10 minute session and tore them to bits. We didn't register a lap time, but the driver was convinced they would be the fastest of the 3. Negative - driver remarked that he wouldn't like to use these on the road as they would be noisy and nervous. Watch this space though - we are getting some medium compound rears and will test again, these look super promising as a track tyre.
3rd up Avon ZZR - we had been advised to run these at around 2 bar hot. After a 20 minute session, the driver was moderately happy with the rear tyres. Once up to temperature they stayed very consistent and were never in danger of overheating no matter how much he abused them - looking at the stiff construction and much harder compound than the other tyres tested this wasn't a surprise, and would certainly indicate that the tyres would last very well. The 'problem' was with the front tyres - too hard, no real steering feel - the driver remarked that the car was great fun to drive as the only way to get it to steer properly was to slide the rear of the car. The car was overly prone to initial understeer followed by snap oversteer. He also remarked that this was not a tyre for the novice driver because of the way it needed to be driven to get the best out of it. We let the front tyres down to 15psi hot (where we would run an A048-R), and it was better, but not improved a great deal. The driver remarked 'you wouldn't put these on a car to give to a journalist or you would be back to the reviews of years gone by about the car being unbalanced and twitchy'. That said, the driver was surprised that the ZZR was only around half a second a lap slower than the Yokohama, as they felt like they would be a lot slower. It must be said that with more setup time with these tyres on a car performance could be improved, but we decided that the tyre wasn't a good enough option to spend the time that we had available playing with it.
In summary then:
1. A048-R - buy as an all round tyre (as we know already!)
POSITIVES - a good all round tyre, quick to warm up, car is balanced, good overall grip, good for the novice/intermediate driver who won't overheat the rear. An advanced/expert level driver will also like this tyre because of the good grip and he can 'manage' the tyre to prevent it from overheating (as evidenced in Atom Cup when quite often the drivers last lap was his fastest).
NEGATIVES - The good grip means high wear. The rear tyre can be overheated when pushed.
2. Kumho V70A - to be confirmed, looks good, prices TBC
POSITIVES - front tyre superb. Rear tyre excellent grip initially. Overall looks like it could be the best of the lot with more testing.
NEGATIVES - Rear tyre as tested too soft, tore to bits very quickly. Although not tested on the road, driver didn't think it would be as good a tyre as the Yoko on the road. Watch this space.....
3. Avon ZZR - buy for good mileage, a good rear tyre, cheaper than A048's
POSITIVES - Rear tyre stays very consistent, won't overheat, front and rear will last very well in terms of mileage.
NEGATIVES - Front tyre too hard a compound, understeer, no real steering feel, not for the novice driver.
So there we have it - if anyone has any specific questions please feel free to ask (not that I can guarantee i'll know the answer

Modified to add prices (from Ariel) for interest
Yokohama
Front £105 + VAT
Rear £140 + VAT
Kumho
Front TBC
Rear TBC
Avon
Front £96.80 + VAT
Rear £126.90 + VAT