Let's not beat around the bush, the Fiesta ST we have here is pretty much identical to the one we tested earlier this year, barring fitment of the Performance Pack and its main ingredient: a limited slip diff. For that reason, we'll get to the point in question rather quickly. Is the optional Quaife limited slip differential this pack brings worth the additional outlay? Or would you be better off saving those pennies - all £850 worth of them - for petrol and jam sandwiches?
We'll get to that in just a sec, promise, following a quick revisit of the basics. You'll know the new Fiesta ST uses a 1.5-litre three-cylinder engine producing 200hp and 214lb ft of torque, giving it enough grunt to hit 62mph in 6.5 seconds and a top speed of 144mph. For a car costing from £19,245 in ST-1 guise, that's pretty good going, but in truth just 1 per cent of STs leave the showroom in this basic form. 71 per cent come in top ST-3 form without the Performance Pack, meaning the car you see here - oh look, an ST-3 sans slip diff - best represents the norm in Britain.
ST-3 cars get 18-inch wheels as standard wrapped in Michelin Pilot Super Sport rubber, as well as red brake calipers. They also come with plenty of kit inside, including an 8.0-inch touchscreen infotainment system with satnav, automatic climate control and slim-fitting leather Recaro sports seats. To your average Joe, an ST-3 looks like a pretty well rounded offer, so it's of little surprise a total of 80 per cent leave the showroom without the slippy diff, launch control and gear shift lights of the Performance Pack.
The venue to test whether Joe is right to ignore this option is a web of roads that twist and interlink across Snowdonia National Park, just south west of Hiraethog. These tarmac ribbons have cambers and undulations, and this being rural Wales in October, are coated in a thin layer of moisture left over by the morning mist. Perfect circumstances, you might say, to test the effectiveness of a diff - or rather, a lack of one. To make sure our perceptions are doubly accurate, we bring along a Performance Pack'd ST-3 for a back-to-back comparison.
Even when focused on analysing one trait of the Fiesta ST's performance, it's hard to overlook how sweetly the thing turns and steers on a UK B-road. It responds to each input swiftly, that perforated leather-coated helm requiring a satisfyingly small amount of input to direct the front end left and right around bends. The ride on these rough and occasionally cracked surfaces is also rather good, and an aggressive right foot doesn't encourage the front wheels to bounce and jitter as they struggle to put the power down like you might imagine. Instead, they grip. Well. So much so that if you drive along this route at six or seven tenths, the non Performance Pack Fiesta ST feels, to be honest, equally as good as the slipp diff'd car. One point to Joe.
Up your efforts and start to demand drive from the front axle while steering lock is applied, however, and the inside wheel will slip. It's not enough to cause an unrequested visit to the surrounding grasslands, but there's a very slight straightening of turn angle and lightening of steering weight that confirms we are in fact experiencing understeer of minute proportions. Joe and his ilk might never explore this realm of pace, but for those of us who take pleasure in feeling a car's suspension load up through a corner as we demand to be slung towards the next, a lack of diff has noticeable effects on progress.
This thought is compounded by a drive in the Performance Pack car, which tackles the same corner exits with a neater line that not only gives you more confidence in the front end, but also more options as to how to embrace its agility. Powering out of a bend while retaining some angle of steering input will see the car tighten its line, rather than the opposite. For us lot, it means you can be even more aggressive with the throttle and encourage the rear end - which is very happy to cock an inside wheel and slip, particularly in the car's Sport and Race modes - to help tighten the line. For others, it simply means you have even more control of the direction of travel, particularly in moist conditions like these.
What of the other features included in the Performance Pack? We're not sure many people would actually miss them if they weren't fitted. It's not like 200hp is particularly difficult to manage manually, or that the three-cylinder engine - as enthusiastic as it may be - revs so quickly that you need a visual reminder to change up at the correct time. Some may like the raciness of such features, but for most part, the £850 bill for the Performance Pack will be for the Quaife diff. The launch control and shift lights are just added bonuses. Or unwelcome gimmicks.
So yes, we've come to a conclusion that, to some extent, many of us probably predicted. Then again, maybe we expected the standard, Performance Pack-free car to falter even more than it does. It's still a fine driver's machine that ranks right at the top of the class, which emphasises how great of a job Ford has done with the chassis of its latest hot hatch. It's just that the diff takes things to the next level. It remains a must have option if you're really serious about driving.
SPECIFICATION - FORD FIESTA ST-3
Engine: 1,497cc, turbocharged 3-cyl
Transmission: 6-speed manual, front-wheel drive
Power (hp): 200@6,000rpm
Torque (lb ft): 214@1,600-4,000rpm
Top speed: 144mph
Weight: 1,262kg (EU, with driver)