It's anyone's guess what the F in the IS-F name means, but after your first blast in it, I'll bet there's only one word that springs to mind: fast. That's what I was thinking anyway, along with a couple of other choice F words, as I slid off the on-ramp and onto the freeway in a haze of white smoke.

I hadn't meant to make such a dramatic entrance to the rush-hour grind but, having spent 20 minutes inching along in traffic, I needed to see if the IS-F really had the bite to go with its fantastic bark. Simple answer: it has, and then some.

I don't know why I doubted it so much. No, actually I do. It's all to do with the Lexus badge. Even though I like to think I don't make sweeping generalisations, I do because it's just easier. So I say all Aston Martins are cool rather than, some Aston Martins are cool, but the N24 is a social liability. And I'll always give Belgium a verbal kicking even though parts of it are properly nice.

Where my keep-it-simple plan falls apart, is when a company like Lexus, which has only ever made brilliantly built but dull cars, produces something like the IS-F. It ruins the whole generalisation game and forces you to be specific. Now, whenever anyone asks me about Lexus I'm going to be forced to say they're all OK, but the IS-F is the very definition of exceptional. Anything else would be wrong, because that's precisely what it is.

Only exceptional really describes accurately what it is, because the rest of the range is as interesting as a blank sheet of paper next to the IS-F. This car is very interesting indeed.

Just as well it is, though, as it would have been laughed out of the bar by the pack of rabid German competitors if was anything like its parents. The Audi RS4, discontinued or not, remains one of the most complete drivers' cars ever made. The Mercedes C63 has already delivered a defeat to the new M3 in TG, but the BMW is still the best-handling car in the class.

To even get close to these cars on the first attempt would have been a towering achievement, but Lexus doesn't do first attempts unless it's completely finished its homework. It doesn't launch cars it thinks are right for the market, it develops them in private until it knows they are right. Then we get them.

It's why their cars don't squeak or creak. It's why nothing ever comes loose or falls off. It's also why they are generally bland to drive. All of the emotion, the stuff that creates character that can't be measured and replicated exactly, is replaced by cold, solidly reliable efficiency. A dishwasher has more soul.

But, with the arrival of the IS-F, all that's changed. In the same way the company studied microscopically, then re-invented the luxury car market, creating a car it felt matched or bettered all the competition in every key area, it's now done the exact same thing with the luxury performance saloon space.

And, for the first time, it's created a car with more spirit than a distillery. It's like it's poured the M3, C63 and RS4 into a blender, given them a good mix and come up with its own blend of tyre-shredding über sports saloon.

You can sense it from the moment you get in. Even at walking pace you don't just feel the road surface, you have a heated affair with it via the tight suspension and direct steering. It's fabulous when you're looking to find the last bit of grip out of a roundabout, but then it's also kidney-jarringly tedious on any journey through town.

There's nothing particularly trick about the suspension - it looks pretty much the same as the standard IS's set up. It's more to do with the way it's all been lightened and tuned that makes the difference.