The third model range to bear the name of SEAT Leon is also the first to be available in an estate body style. SEAT has done its best to give the ST more practicality than either of the hatchback versions by making it nearly a foot longer, and you can find more details about that in our launch report.Briefly, luggage space with the rear seats in place has risen to 587 litres, which is not at all a bad figure and actually exceeds that of the much larger Volvo V70. The Volvo, however, is not packaged particularly well, and there are several other small family estates (including ones built on the same platform by Volkswagen and Skoda) that beat the ST by some margin.So, while the load-lugging part of the SEAT isn't exactly cramped, if you need more space in a car of roughly this size you can get it by visiting a different dealership.I mentioned in the launch report that I don't think STs handle quite as well as Leon hatchbacks, and have since had this view challenged by colleagues who think that they do. Meh and pfft. Call it a matter of opinion if you like, but I still think I'm right.I would say, though, that I don't object to how most STs ride and handle, and would be quite happy to live with any of them. But there's one exception, and by a sad twist of fate it happens to be the one that was sent to CARkeys Towers for a week's evaluation.It's the top model in the range, and it has the 182bhp (or 184PS) version of the two-litre TDI turbo diesel engine. A fine piece of work in itself, no question. It makes the ST perform really quite sparkily, and its official 65.7mpg fuel economy and 112g/km CO2 emissions mean it should be quite cheap to run.Ah, but will it be? Yes, it very possibly might be. In the course of this test I used the considerable straightline performance on several occasions, and on others drove for long periods along motorways in bad weather, which is never a good way of using fuel efficiently.Despite that, I found it easy to stay in the mid to high 50s mpg, and I bet I could average 65.7 if I gave the matter some thought.So what's the problem? Well, the problem is that the suspension, for all that it's described as "sports", hasn't been designed to cope with all that power, and if you're not careful you can find yourself using the steering not so much to direct the car where to go as to persuade it not to go where it wants to. If you see what I mean. It's all a bit clumsy and haphazard, and I think SEAT could have organised things better.If, regardless, you want this engine in your ST, you have to go for the range-topping FR trim level, which includes dual-zone climate control air-conditioning, sports front seats (very comfortable on a long journey, I have to say), front and rear parking sensors and eight audio speakers. Other features are more trivial, but you might like them.FRs run as standard on 17" wheels, but 18s are available as an optional extra. They do nothing for the ride quality, though, so I suggest you avoid giving them a second thought. Engine 1968cc, 4 cylinders Power 182bhp Transmission 6-speed manual Fuel/CO2 65.7mpg / 112g/km Acceleration 0-62mph: 7.8 seconds Top speed 142mph Price £23,380 Details correct at publication date