The new MINI has been a worldwide success, so the
new MINI Cooper S is very much like the old one. But thanks to a new engine it is quicker. The Cooper S will now hit 140 mph and reach 60 mph in under 7 seconds.
The main change is to a brand-new range of BMW 1.6 liter engines, produced at the company's engine plant in the UK. Previously, the MINI engines were built in a joint venture with Chrysler.
To meet safety regulations, the car has been made a bit bigger – the car is now just over 2.0 inches (60 mm) longer. A pity, as that increases the weight as well.
There are minor changes to the appearance, with slimmer bumpers and a large lower grille matching the main grille. The Cooper S gets a higher hood to leave space for the turbo, with an extra air intake. At the rear the bumper is shaped to leave a cut-out for the twin exhausts.
Amazingly, just about every panel is new, yet the car looks almost the same as the old one! Even so, the drag has been reduced – the Cd is 0.33 compared with 0.35 for the old car.
New BMW direct injection 1.6-liter engine
Under the hood there is now a 1.6 liter BMW 16-valve engine with Valvetronic variable valve timing and lift, which not only gives more power but also improves fuel economy by a worthwhile amount – 12%. Power output of the Cooper S is up 5 bhp to 175 bhp at 5,500 rpm, with maximum torque of 177 lb ft (240 Nm) available from 1,600 to 5,000 rpm.
Whereas most companies make a song and dance about moving to direct injection (DI), BMW just slides them in. DI is one of the reasons for the better fuel consumption, and the Valvetronic engines are ideal for DI because they have no butterflies to control power output. Instead, the valve lift is altered not just to increase or decrease power, but also to bring the engine to an idle.
This is possible because the lift can be varied from zero to the full lift, allowing a good spread of power at all speeds. These are without doubt among the most advanced engines produced anywhere in the world, combining low fuel consumption with great performance. The new MINI Cooper S is not just faster than the old cars, but has better response at any speed as well..
Turbocharged not supercharged
Unlike the old engine,the new BMW unit is turbocharged, with a twin scroll turbocharger. The gases from each pair of cylinders go to one scroll intake in the turbocharger. The result is quicker response, which BMW says is almost free of turbo lag. Incidentally, turbo lag and poor fuel consumption kept BMW away from turbos until now – turbos are used on the new bigger BMW engines as well.
An advantage of turbos is that they can be allowed to overboost for short periods to give that extra power you need to overtake safely. This is one of the features of the new Cooper S engine, boosting maximum torque to 191 lb ft (260 Nm) from 177 lb ft from 1,700 to 4,500 rpm – a really useful feature.
To reduce weight, composite camshafts are used, and the cylinder block and head are aluminum. There is a separate bedplate for the main bearing caps to increase durability.
Fuel consumption is also improved slightly by the use of a water pump which is driven only when needed. As before, the engines are coupled to six-speed manual transmissions, but a six-speed automatic will be available later.
New rear suspension
At the front, BMW engineers have stuck with MacPherson struts. This is a simple set-up with A-shape lower links, and anti-roll bars. Nothing special here.
At the back, the expensive and heavy multi-link system has been replaced by simpler and cheaper three-link wishbones. This is very simple and light, but does not give quite the same movement as a multi-link system.
There are a pair of links acting as wishbones each side - as shown in the diagram of the rear suspension, with the help of an anti-roll bar. These are angled forward from the hub to a cross member, and give no fore-and-aft control. Fore-and-aft control is provided by an aluminum trailing link each side.
The hub carrier is part of this trailing link, and this is why only one trailing link is needed. Normally, two trailing links would be needed each side.
Ant-squat
So it this any good? Well, the trailing links give anti-squat on acceleration, which is good, and the transverse links are arranged to give a high roll center, which is good on a front-drive car. It should work pretty well.
One small disadvantage of this layout is that the cross member is quite high, cutting into the space for the fuel tank and luggage – and the MINIs all have precious little luggage space.
MINIs have had pretty direct steering from the word go, and this is being retained on the new car. Now, though, you get electric power assistance, which gave the engineers the chance of offering two types of steering. Standard steering is still fairly quick, but press the Sport button and you get even more direct steering.
As standard, the MINI Cooper S has16-inch aluminum wheels with 195/65 R tires, but there is the option of 17-inch wheels with 205/45 R17 tires. Either way, you get run-flat tires, which some people find don’t have the same response or cornering power as normal tires.
As you expect with a new range from a mainstream maker like BMW, there are plenty of safety features including ABS, electronic brake force distribution and CBC Cornering Brake Control. ASC+T Automatic Stability Control + Traction is standard on the MINI Cooper S with on-off control by the driver, and there is an optional DSC Dynamic Stability Control.
What with the new safety regulations and the higher specification, the new car is heavier than the old one, despite the lighter engine. That's commonplace but a pity on a car like the MINI.
