This is an interesting comparison as it is a bit of sibling on sibling rivalry. Both Audi and Porsche are under the VAG umbrella so they are part of the same company yet the execution and vision of both of these cars are completely different.

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The TT-RS is the brute. It has more power and it's all about putting it down to all four wheels to dust its competition. That is not to say it does not shine in the corners as it does but it just does not do it like the Cayman S.

The Cayman S is lighter with a mid-engine layout. This example tested is a 6-speed manual version. Perhaps that says plenty as to the intended audience. The TT-RS is dual clutch only. The Cayman S offers a PDK dual clutch as an option.

Right off the bat you know the Cayman is at a disadvantage due to the transmission choice. Yet, maybe it has an advantage in the eyes of a purist driver? Car and Driver thinks the Porsche manual is the best in the business. The interaction provided outweighs the tenths of a second lost in shift time.

It wouldn't matter if the Cayman S had a PDK anyway. The TT-RS is getting to 60 in 3.2 seconds. It gets to 100 in 8.1 seconds or over a second faster than the 718 S. The 1/4 mile sprint takes 11.6 seconds at 119 miles per hour. Even a 911 Carrera PDK would lose the straightline battle.

So what? This is about which is the better sports car. The Audi has 60% of its weight on the front nose. Yes, 60%. The 718 by contrast has a 44.6/55.4 percent front to rear split. It's also lighter 175 pounds at 3102.

The TT-RS pulls more on the skidpad at 1.05g to 1.04g but the Cayman S gets through the slalom at 47.1 mph compared to 46.7 mph. Sometimes it isn't all about outright grip but transitions and the Cayman clearly has the better combination of grip, weight, and balance.

Car and Driver picks the Cayman S as the better sports car. They say it is one of the best cars in the world at any price point. They're not wrong.

Imagine if the 718 S had the TT-RS powerplant though. Wouldn't that be something?

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2018 Audi TT RS 2017 Porsche 718 Cayman S
VEHICLE
PRICE AS TESTED $80,200 $81,590
BASE PRICE $65,875 $67,350
DIMENSIONS
LENGTH 165.0 in 172.4 in
WIDTH 72.1 in 70.9 in
HEIGHT 52.9 in 50.2 in
WHEELBASE 98.6 in 97.4 in
FRONT TRACK 61.6 in 59.6 in
REAR TRACK 60.7 in 60.6 in
INTERIOR VOLUME F: 47 cu ft
R: 27 cu ft
F: 49 cu ft
TRUNK 12 cu ft 15 cu ft
POWERTRAIN
ENGINE turbocharged DOHC 20-valve inline-5
151 cu in (2480 cc)
turbocharged DOHC 16-valve flat-4
152 cu in (2497 cc)
POWER HP @ RPM 400 @ 7000 350 @ 6500
TORQUE LB-FT @ RPM 354 @ 1700 309 @ 1900
REDLINE / FUEL CUTOFF 7000/7200 rpm 7400/7500 rpm
LB PER HP 8.2 8.9
DRIVELINE
TRANSMISSION 7-speed dual-clutch automatic 6-speed manual
DRIVEN WHEELS all rear
GEAR RATIO:1/
MPH PER 1000 RPM/
MAX MPH
1 3.56/5.2/37
2 2.53/8.6/62
3 1.68/13.0/94
4 1.02/18.2/131
5 0.79/23.5/169
6 0.76/28.7/174
7 0.64/34.1/170
1 3.31/6.2/47
2 1.95/10.6/80
3 1.41/14.6/110
4 1.13/18.2/136
5 0.95/21.7/163
6 0.81/25.3/177
FINAL-DRIVE RATIO:1 4.06, 3.45* 3.89, limited-slip differential
CHASSIS
SUSPENSION F: struts, coil springs, anti-roll bar
R: multilink, coil springs, anti-roll bar
F: struts, coil springs, anti-roll bar
R: struts, coil springs, anti-roll bar
BRAKES F: 14.6-inch vented, cross-drilled ceramic disc
R: 12.2-inch vented disc
F: 13.0-inch vented, cross-drilled disc
R: 11.8-inch vented, cross-drilled disc
STABILITY CONTROL fully defeatable, competition mode, launch control fully defeatable
TIRES Pirelli P Zero
255/30ZR-20 (92Y)
Pirelli P Zero
F: 235/35ZR-20 (88Y)
R: 265/35ZR-20 (95Y)
C/D TEST RESULTS
ACCELERATION
0–30 MPH 1.2 sec 1.6 sec
0–60 MPH 3.2 sec 4.1 sec
0–100 MPH 8.1 sec 9.3 sec
0–150 MPH 21.4 sec 23.7 sec
¼-MILE @ MPH 11.6 sec @ 119 12.4 sec @ 115
ROLLING START, 5–60 MPH 4.1 sec 5.5 sec
TOP GEAR, 30–50 MPH 2.6 sec 7.9 sec
TOP GEAR, 50–70 MPH 3.0 sec 5.4 sec
TOP SPEED 174 mph (gov ltd, mfr’s claim) 177 mph (drag ltd, mfr’s claim)
CHASSIS
BRAKING 70–0 MPH 140 ft 144 ft
ROADHOLDING,
300-FT-DIA SKIDPAD
1.05 g 1.04 g
610-FT SLALOM 46.7 mph 47.1 mph
WEIGHT
CURB 3277 lb 3102 lb
%FRONT/%REAR 60.5/39.5 44.6/55.4
FUEL
TANK 14.5 gal 16.9 gal
RATING 93 octane 93 octane
EPA COMBINED/CITY/HWY 22/19/29 mpg 22/20/26 mpg
C/D 750-MILE TRIP 20 mpg 20 mpg
SOUND LEVEL
IDLE 46 dBA 51 dBA
FULL THROTTLE 83 dBA 86 dBA
70-MPH CRUISE 70 dBA 73 dBA
*The first ratio is for gears 1, 4, and 5. The second is for 2, 3, 6, and 7.