There are two comparisons by which most people will judge this RS: in reference to the very highly rated outgoing 991 GT3 and against the phenomenally well-received 997 RS 4.0 version of the previous-generation 911.

Compared with the former, it’s hard to imagine any owner will feel short-changed; relative to the latter, the comparison is not quite so clear-cut. But be in no doubt: next to either, this 991 RS is a big step forward.

Matt Prior

Matt Prior

Road test editor
The car is still lighter than the narrower 991 GT3 as standard, and you can make it lighter still by optioning a lithium ion battery, for example, or deleting the stereo

Porsche’s time-honoured approach to making these cars has been not only to add power but also to reduce weight. This time around, it has gone further by adding width and massively improving aerodynamic performance.

So when you find out that only 10kg has been taken out of the car relative to the 991 GT3, and that the 493bhp peak power output is identical to that of the 997 RS 4.0, you’ll understand that you’re only looking at part of Porsche’s design and engineering effort with this car.

This is the first RS ever to use the extra-wide body from the 911 Turbo as its basis. Here, it’s augmented with a magnesium roof, a bonnet, front wings, rear deck and rear spoiler all in carbonfibre-reinforced plastic (CFRP), a rear apron in a new polyurethane-carbonfibre polymer and polycarbonate glazing for its side and rear windows.

It also allows the RS’s axle tracks to grow, to the point where the rear track is some 72mm wider than that of a standard 3.4-litre Carrera and the tyres are the widest yet to be fitted to a road-going 911.

The car is still lighter than the narrower 991 GT3 as standard, and you can make it lighter still by optioning a lithium ion battery, for example, or deleting the stereo.

A long-throw crankshaft made of extra-pure tempered steel delivers the 4mm of added piston stroke necessary to take the GT3’s 3.8-litre flat six out to 3996cc. The engine also uses a new induction system, breathing through the lateral air intakes of the Turbo’s body rather than through the rear deck cover like every other 911. This gives more ram-air effect for the engine and makes more power available at high speeds. A titanium exhaust also saves weight.

The suspension has been updated and retuned, with more rigid ball-jointed mountings and helper springs fitted at the rear, while Porsche’s optional carbon-ceramic brakes get a new outer friction layer.

Which is to say nothing of the RS’s biggest advancement over any other 911: downforce. The rear wing makes up to 220kg of it, while the front spoiler and body profile generates up to 110kg. In both respects, that’s double the downforce of the RS 4.0.

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