Why do we drive the cars we do? It\'s usually a choice driven by budget, image, practicality, economy and purpose. Logic says that there\'s absolutely no need to drive a hulking great 4x4 with a big, thirsty engine, if all we\'re doing is commuting around the city and popping out to the shops. And yet, we often do. In reality, big SUVs offer less protection and no more room than a well-engineered estate, their full economy and handling are worse, and their environmental impact is commensurately greater as a result. What we should be driving, if head ruled over heart, is something more compact, well built, comfortable and efficient, with decent crash protection and useful technology. Enter possibly the perfect city car. It\'s a Lexus IS, the smallest four-door saloon they make, a sort of entry-level version designed to create an affordable pathway into the brand and introduction to their levels of luxury and technology. So it is relatively compact. Being a Lexus, it is also exquisitely well built. Everything feels solid and chunky, there\'s no hint of squeaks and rattles, and all the materials used are a delight to touch. Plastics are soft, metal brushed, leather beautifully stitched. In short, the sort of car and interior in which it is a pleasure to find yourself. Save on petrol It is also a very modern design, with all the fuel efficiency and performance advantages that advanced engine design can bring. In this case, that means clever, fully variable camshaft timing to offer improved torque at low revs and more power at higher levels, but reduced CO2 emissions throughout the range. Great news at the fuel pump. Safety is also a high consideration, and this car carries a full complement of dynamic and passive safety technologies, including adaptive cruise control, blind spot warning lights, braking assist, vehicle stability control and rear view monitors. Air bags aplenty - front, side, knee, curtain - and seatbelt pre-tensioners as part of the ‘pre-crash safety system\' are designed to help reduce the risk and force of impact. There\'s just one teeny little problem - starting with the badge on the side of the wing. It\'s a little stylized ‘F\' shape, and apparently it is derived from the shape of a bend at the Fuji Speedway in Japan. And that tells you that this particular car is the Lexus IS F, the pumped-up, fire-breathing version of their saloon, designed to take on the Germans with their RS and AMG versions. You see, this particular modest little saloon packs a decidedly unmodest 5.0-litre V8 under that swollen bonnet, an eight-speed gearbox, lowered suspension and 19\" light alloy wheels. This is as unlike a Lexus as a Lexus can get. In fact, rumour has it that there wasn\'t supposed to be an IS F at all. Apparently, it was developed in secret by a couple of engineers who wanted to see how far the ‘baby\' saloon could be developed, using parts from the rest of the range. The glorious V8 crammed into the engine bay is borrowed from the much larger LS 460 saloon, though in this version it is fitted with high performance cylinder heads developed by Yamaha, featuring some very advanced variable valve timing technology. This peach of an engine churns out a very healthy 417bhp, and 505Nm of torque, enough to propel the 1,700kg IS F down the road at what feels like warp-factor speeds. That\'s 0-100kph in under five seconds, and a top speed of 270kph. But that doesn\'t tell the whole story - it is the amount and availability of urge through the gears that really impresses. Overtaking is a speed of thought manoeuvre, and massive Brembo brakes mean you can slow down with as much authority as you can speed up. This is a deeply satisfying car to drive, because there is always lots in reserve. You simply decide how fast or slowly you wish to be travelling, and the car delivers. Sharp response Developed at Fuji Speedway and at the Higashi-Fuji Technical Center in Japan, the IS F was the first model to combine ‘Lexus\' and ‘performance\' in the same sentence when it was introduced for the 2008 model year. For 2012, the IS F receives new and wider 19\" forged dark allow wheels, a revised fascia, all-new red leather trim and various upgrades to programming and technology. Suspension wise, the same exclusive ‘F\' set-up is carried through, but with a raft of track-inspired modifications. The IS F sits an inch lower on its suspension than the standard IS models, which lowers the centre of gravity and helps provide a sharper response to your inputs. The rear suspension control arms optimise geometry for the new 19\" wheels; the monotube shock absorbers use a larger-diameter piston rod; subframe suspension mounts are stiffer to help reduce roll and enhance control; and the engine mounts are also stiffer for a more direct feel. All of this adds up to create a car that feels alive in your hands, ready for your slightest input. On the road, this translates into a ride that is firm without ever being brittle, communicative rather than harsh. The IS F remains supremely comfortable. Standard fixtures on the IS F include ten-way power adjustable front seats and a powered steering wheel with reach and rake, coupled to three memory pre-sets for different drivers. The dual-zone air conditioning system adjusts output to demand rather than simply cycling on and off. UV-reducing, heat-absorbing glass is used. Hi-fi buffs will appreciate the fact that the IS F offers an optional Mark Levinson Premium Surround Sound Audio System, with 14 speakers and ten amplifier channels each providing 300 watts total output. You can also watch DVDs on the 7\" navigation screen when the car is in Park mode. The IS F does almost everything anyone would wish a car to do, in a compact and comfortable package brimming with efficiency and technology. It is also endowed with an extraordinary turn of speed for when you\'re bored of the city and need the raw excitement of the open road. Which I guess makes it not so much the perfect city car, as the perfect all-rounder.