Ten things we learned about the new Ford Fiesta ST


#1 The aero is real
The front chin, rear spoiler and rear diffuser do actually cut lift, even if not to the point where lift goes negative - ie downforce.

#2 Don't fret over the wheel options
The standard wheel is a 17, the optional an 18. But Leo Roeks, head of Ford Performance in Europe and the man most in charge of the ST's development, says they drove so similarly most people won't be able to tell the difference. Both wear the same Michelin Pilot Supersport tyre type.

#3 You want the Performance Pack
This brings you the limited-slip differential, made by motorsports people Quaife. Plus shift-up lights and launch control. That's ?850 and sounds to us like a bargain because LSDs are expensive pieces of mechanical engineering, and this one is calibrated beautifully so the ST spits itself out of tight corners on full power with nary a trace of understeer.

#4 The springs are bananas
Ford has invented a new kind of spring for the rear suspension. It's slightly banana-shaped, so when it's compressed it exerts a sideways force. Normally with a torsion-beam suspension, the sideways force on the outer tyre causes the beam to move in its bushes, slightly steering the back end of the car in an inconsistent way. That mucks up steering precision. As a countermeasure, sporty cars get stiff bushes, which is bad for comfort. These new springs are oriented in the chassis so that when the car begins to roll in a corner and the outer spring is compressed, that spring pushes back against the wheel's lateral force, keeping the wheels pointing straighter. So the new arrangement lets the bushes be tuned softer for better comfort, while the steering precision remains.

#5 It's got canny dampers
The dampers aren't adaptive, and pressing the sport button doesn't change them at all. But they do a have an unusual characteristic. In big-stroke relatively slow movements - body control when you're going for it - they're fairly firm. But for quick short movements they're relatively soft, helping the ride.

#6 The steering is very positive
The steering ratio is very direct - your smallest hand movements summon vigorous direction change. On some cars that's a bad idea, because without precise steering, it feels twitchy and inconsistent and you lose confidence. After a brief acclimatisation the ST is just fine. You revel in the quick answers, but it all feels natural. And it grips more, not least because of better tyres and a 48mm wider front track.

#7 It all works together
All these bits of chassis geekery harmonise beautifully. Most sporty-car suspension engineers would want stiff dampers even in the small-stroke high-frequency events, because that quells roll changes, improving steering precision. (It means that even for a small change in steering wheel angle, you get a change in car direction, rather than wasting the initial impetus on a roll-angle change.) The ST instead draws better steering precision from its new rear suspension, thanks to those clever springs. So again it doesn't need such firm high-frequency damping. It's been set up on relatively soft springs and bushes, and its short-amplitude damping is more pliant too. That means better road noise suppression and less ride harshness. And the quick steering makes it agile.

#8 It's got a clever engine
The headline tech feature of the new three-pot engine is the cylinder cutoff system. When you're light on the gas this allows it to run on just two of the three. You never feel the join, by the way, but the economy improvement is noticeable. Still, it's a performance engine too. It's got an oil cooler for hard work, and both port and direct injection to hose in the fuel when you need power.

#9 It sounds good, too
There's less of the twittery warble we've come to expect from little three-cylinder engines. It's more purposeful, but still with character. There's a bit of sound enhancement through the speakers, but it's ?live' sound played through filters to get the best notes - not false synthesis. There's also a flap in the exhaust. Sport mode opens the flap and turns up the enhancement too. And it brings over-run pops, but not to the embarrassing degree some more juvenile rivals fire at you.

#10 It's not the most powerful Fiesta, but it is faster than before
The quoted power output is the same as the old Fiesta ST200. But the ST200 had access to overboost nearly all the time, so it made 215PS or 212bhp. And the new car is 20kg heavier thanks mostly to a stronger body shell. Even so the new one accelerates faster because it gets it to the road better. Thank the LSD and the grippier tyres and the launch control.