The 2021 Porsche 911 Turbo S Compared to Its Predecessor

They may look very similar, but under the classically organic 911 bubble with a wing, there are many differences.

In case you missed it, in our First Drive of the 2021 Porsche 911 Turbo S, we said, "The 2021 911 Turbo S is alive, eager, and hungry. It needs its driver, rewards its driver, and it bonds with its driver. This is the car you marry." So, what changed from the last generation (991.2) 911 Turbo S to the new 992 version? Let's take a look.

911 Turbo S Engine Specifications

Let's start with the obvious: their DOHC 24-valve twin-turbo flat-six engines. For the 2021 model, displacement actually went down by 55cc (3,800cc for the 991.2 to 3,745cc for the 992), and the compression was lowered from 9.8:1 to 8.7:1. Yet, horsepower rose by 60 at the same engine rpm (580 hp to 640 hp @ 6,750 rpm), and torque swelled by 37 to 74 lb-ft depending on the overboost conditions of the old car (516 or 553 lb-ft to 590 lb-ft). The new Turbo S does not require overboost conditions; it's full-boogie full-time. By the way, the new car can send more than half of the engine's torque, as much as 368 lb-ft, to its new, lighter, and liquid cooled front axle. The overall power density of the 911 Turbo S' engine increased from 152.6 horsepower per liter of displacement to a staggering 170.9 hp/L. How did Porsche do that? Bigger, higher maximum boost (from 18.1 to 22.5 psi) and "smarter" variable-geometry turbos with increased air intake (rear flanks and rear deck), improved charge air cooling, and more-direct now-symmetrical exhaust flow to the turbos.

What's The 911 Turbo S' 0-60 Time?

Combined, the results, according to Porsche, improve the 911 Turbo S' 0­-60 time by 0.2 second and will shave 0.3 second from its quarter-mile time. Applying those estimates to the last 911 Turbo S we tested twice (a 2017-model year 991.2 with different sets of tires), or the hardest launching vehicle we've recorded, would mean the 2021 Turbo S should scoot to 60 mph in a scant 2.3 seconds. That would tie the Tesla Model S P100D Ludicrous+, the quickest-ever production car 0-60 we've ever recorded. From a stop, it would mean the new Turbo S would cover a quarter mile in 10.2 seconds. And that would put it sixth on our all-time leader board behind: Ferrari LaFerrari (9.7 sec), McLaren P1 (9.8), Porsche 918 Spyder (10.0), McLaren P1 and 720 S (tied at 10.1).

Sure, there's power and power density, but as we've seen with two otherwise identical Mustang GTs (one with a six-speed manual, the other with a 10-speed automatic), gearing can also play a major role in acceleration.

Seven-Speed Versus Eight-Speed PDK 

Not that the seven-speed PDK in the 2017 911 Turbo S wasn't special, but the 2021 Turbo S has an extra special eight-speed twin-clutch automatic. As Porsche's product spokesperson (and 911, Boxster, and Cayman savant) Frank Wiesmann explained, "The PDK in the new 911 Turbo S features a reinforced clutch with two additional pairs of discs for the purpose of transferring higher 'torques.' This means that the [2021] 911 Turbo models have a total of six pairs of discs with twelve friction surfaces." We did some deeper investigation regarding actual gearing, and the new Turbo S has an advantage here, as well. Warning: lots of numbers ahead.

What's The Difference In 911 Turbo S Gearing?

Because the Turbo S' front-rear torque split is continuously variable, and a snapshot of when and where the power is being optimally distributed is not possible, for this comparison to work we had to pretend the split is 50-50. Using the gearing charts supplied to us, and despite what appears to be more conservative axle ratios for the new Turbo S, when we combine those differing axles with each of the cars' gear ratios, we can see a clear torque multiplication advantage for the 2021 model. In first gear, for instance, the amount of force (1,838 pounds) that the 992 Turbo S is putting to the pavement at each of its four tires' contact patches is 250 pounds greater than that of the 991.2's, or a total deficit of 1,000 pounds. In first gear, the roughly 3,550-pound 991.2 Turbo S produces a total 6,352 pounds of force at its tires, and the estimated 3,650-pound 992 Turbo S makes 7,352 pounds, or more than twice its curb weight. Imagine that launch, presuming it doesn't smoke all four tires! In second gear, where both cars reach 60 mph, the 992 has an overall 1,046-pound force advantage. As quick as the last 911 Turbo S was, this new one, once we get to test it, will be giant slayer.

911 Turbo S Chassis Details

Wheels and tires have grown between generations of Turbo S. The 992 Turbo S now has staggered wheel sizes now (20-inch front; 21-inch rear), and they're the racy center-lockers like the GT cars have. Standard tires have grown from 245/35ZR20 91Y and 305/30ZR20 103Y (Pirelli P Zero N1) to 255/35R20 93Y and 315/30R21 105Y (Pirelli P Zero NA1). Both come standard with multi-adjustable dampers and rear-steering axles, but the new Turbo S can for the first time be optioned with PASM (active) Sport Suspension with a 10mm-lower ride height. It's set up to be compatible with the Turbo S' standard active-roll stabilization (PDCC), and with helper springs on the rear axle, this new option calculates and adjusts damping rates approximately 200 times per second, making it the best-riding Turbo S ever. Carbon-ceramic disc brakes remain standard on the Turbo S, but the front rotors' size has grown from 16.1 inches to 16.6 inches. Also, the front calipers now have 10 pistons instead of six.

Does The 911 Turbo S Have Active Aerodynamics?

There are so many permutations to the new 911 Turbo S' aerodynamic control systems, we could write an entire piece on it alone. The main moveable elements consist of the multi-stage front splitter, the variable louvers in the front fascia, and the rear wing—with effectively 8 percent more surface area—which can now alter both its height and angle of attack. Clever monitoring of the driving modes (now including "Wet") and the driver's behavior affect drag, anti-lift (a.k.a. "downforce"), and even will deploy as an air brake from high speeds. In the highest performance mode, downforce has been increased by 15 percent compared to the previous Turbo S. The 992 can be slippery for efficiency or top speed (205 mph) or buttoned down for stability and handling. Our test car was also equipped with the yet-to-be-priced Sport Design package that presumably subtly tweaks some of the car's aerodynamics.

Is The New 911 Turbo S Bigger?

Riding on the same 96.5-inch wheelbase, you'd be hard-pressed to see the length, width, or height differences between the two generations of 911 Turbo S. Respectively, the new car is 1.2 inch longer,0.9 inch wider, and 0.1 inch lower. More important, the new Turbo S' wider wheels have been pushed farther apart by a not-insignificant 1.7 inches up front and 0.4 inches out back. Inside, front/rear headroom has increased by 0.2/0.3 inches, legroom by 0.1 inch in back, and shoulder room by 1.3inches in front. Cargo capacity in the "frunk" and behind the rear seats has increased by 0.6/0.1 cubic feet. Lastly, the standard fuel tank shrank by 0.3 gallon. We don't think you will miss that liter of fuel, as we're estimating it will be more fuel efficient by at least 1 mpg across the board.

Have You Tested The 2021 Porsche 911 Turbo S?

So, there you have it. We were delighted to drive "the best Turbo S ever," and can't wait to put it on a set of scales, attach our Vbox data logger and tell you what the 2021 Porsche 911 Turbo S will really do. Until then, here's how some of our staff would configure their own dream car. How would you build yours?