The super-saloon class has, in recent years, been dominated by the Germans – and, to a lesser extent, the Italians.

Upstarts such as Polestar are hoping to muscle in by taking the familiar recipe and making it ‘fusion’: get hold of a big, comfortable saloon with a plush interior and supercar power, just like mama used to make, but instead of fitting a straight six, a V8 or a V10, bolt an electric motor to each axle.

In my mind, my Polestar 4 is more a very fast EV and not quite a super-saloon. So I lined up the 536bhp, all-wheel-drive 4 against a near-identical example fitted with the full-fat Performance Pack to see if this turns it into an Alfa Romeo Giulia Quadrifoglio fighter.

This pack adds no extra power (which, frankly, the car doesn’t need) but includes 22in wheels, more firmly calibrated ZF dampers and Brembo brakes with 392mm front discs. Oh, and gold seatbelts.

This enhanced 4 was finished in the same Electron baby blue as mine, but it wore £900 body-coloured lower cladding—a worthwhile option in my view. It makes the car feel less SUV-lite and more like a traditional saloon. Except it is, technically, a hatchback — but you know what I mean.

I took both cars to Bicester Motion’s one-kilometre handling circuit, a tight and technical layout, to see how they compared. This was the first opportunity I had to drive my own car properly in anger. It is brutally quick. The back straight at Bicester is only 310 metres long, yet by the end of it I was already sailing past 90mph.

Polestar’s throttle mapping is unusually aggressive. Range mode is not a conventional eco setting - the throttle never feels especially dulled and performance remains more than ample. Performance mode, meanwhile, allows full throttle with very little pedal travel. The steering offers several weight settings but limited communication.

Even with the stability control in Sport, the dominant trait is understeer. Trail braking, lifting mid-corner, mashing the accelerator – nothing really elicited much in the way of fun. Grip levels, however, are enormous. One novelty I encountered for the first time was brushing against circuit noise limits in an EV – yep, that’s right, due to the howls of pain from the tyres.

The only hardware changes in the Performance Pack concern suspension and brakes, and that is where the differences lie. The Performance Pack adds stiffer springs and anti-roll bars, which reduce body roll - and you can feel it.

There is a tight, near-90deg corner before the main straight, and the Performance Pack car allows you to commit to full throttle sooner. On the road, admittedly, the benefit is less clear. Besides, I drive most heavy EVs with their dampers in the softest setting anyway.

The upgraded brakes, by contrast, make a meaningful difference. The transition between regenerative braking and the discs is smooth in both cars, but the Performance set-up delivers greater bite and urgency when you really lean on them.

Pedal feel is excellent, inspiring considerable confidence. Possibly too much confidence. After a few stops from 90mph there was, er, a little smoke. Slowing 2.3 tonnes in a hurry is never easy.

Would I recommend the Performance Pack? At £4000 it’s neither fish nor fowl considering this is a £70k car. It sits awkwardly in the middle ground and adds about £60 a month to typical payments. The wheels look better and give the 4 more presence, and the suspension I could take or leave, but the brakes are superb. For some buyers, that will be justification enough.

And what of the Polestar 4 Performance Pack as a super-saloon? EVs deliver a very different experience from 500bhp petrol equivalents such as the Giulia QV that I ran last year. The Quad is sharp and precise, sounds magnificent and feels pleasingly analogue despite its automatic gearbox.

The Polestar is more of a contradiction: closer, perhaps, to a point-and-squirt muscle car, defined by prodigious straight-line pace. Just one with a conscience, and an air-quality system - which, in this case, prompted me to purify the cabin after those smoking brakes.