I could barely stifle an ironic chuckle as I took to the wheel of the top-ranking Legacy Outback shortly after a Subaru person had told me that the company's UK sales had been particularly impressive in December 2010 because of the bad weather. The reason for my cynicism was that this Legacy is fitted with tyres which, whatever else they may do, are not going to be of the slightest help in bad weather.As standard, this particular Legacy is fitted with 18" wheels, on which reside 225/45 Bridgestone Potenza tyres. The tyres on the Cosworth Impreza STI CS400 are only slightly racier than this, and you wouldn't want to take that out in the snow, would you? No, you wouldn't.The dimensions of the Potenzas aren't very useful in dry weather, either. The whole point of a good Subaru is that it rides on soft but well-damped suspension, leading to excellent roadholding and impressive ride quality. If you stick 45-section tyres on it, bim goes the ride, as the Legacy demonstrates all too effectively.There are other reasons why, if I were to buy a Legacy (a car I generally like), this would not be the one I would choose. The best Legacy - reviewed here - uses Subaru's long-awaited and really rather good 148bhp two-litre turbo diesel engine. This one has a 165bhp 2.5-litre petrol, and it's available only with the Lineartronic transmission which nearly everyone else describes as a CVT automatic.Lineartronic works well, but it also soaks up more than the 17bhp advantage the 2.5 engine has over the diesel. This makes no difference to the 120mph top speed, but it does hamper acceleration to the extent that the most powerful Legacy is also one of only two (the 2.0 petrol Lineartronic being the other) which takes longer than ten seconds to get from 0-62mph.It is also, by a tiny margin, the most expensive car in the range, and its interior doesn't seem to justify a list price of slightly over £27,000, not including satellite navigation. The diesel SE comes within £5 of its price and is in a lower insurance group, but it will be cheaper to run thanks to its greatly superior fuel economy (44.1mpg combined rather than the 33.6mpg of the 2.5) and lower CO2 emissions - the 2.5's 195g/km rating puts it in VED Band J, which currently means that its standard rax rate is £245 per year.There is a lot to be said for the Legacy as a whole, most of it concerning its handling, its practicality and its excellent results in various crash tests. But I wouldn't choose this car. For me, these days, a good Legacy is a diesel Legacy. Engine 2457 cc, 4 cylinders Power 167 bhp @5600 rpm Torque 169 ib/ft @4000 rpm Transmission 6 speed semi-auto Fuel/CO2 33.6 mpg / 196 g/km Acceleration 0-62mph: 10.3sec Top speed 127 mph Price From £25976.00 approx Release date 01/10/2009