The last of the aircooled rear-engined Porsches is the 993, final permutation of the fabled and long-lived aircooled 911 line. The very first 911 (Actually badged as a 901) was built in 1964. The car I’m reviewing is a 1995 Porsche 993 with the Tiptronic transmission. To some hard-core Porschephiles the very idea of an “automatic” transmission is anathema. After all, the 911 has an incredible record of racing wins that stretches back over 30 years. It’s the essential high-performance sports car, and you assume that the owner/driver prefers to shift a manual transmission, right?
Well, sort of. There’s been an “automatic” version of the 911 for a years, although overall sales have only been a fraction of the manual transmission cars at any given time. The Tiptronic has been through several stages of development, and this last model is the very best yet. But I believe the term “automatic” transmission is a misnomer. It’s true the shift lever can be left in Drive and the car will move along shifting itself, but that’s not getting the most our of a very sophisticated and evolved system.
All this interest in “automatic” transmissions for powerful sports cars stems directly from advances made in Formula One racing. F1 cars all use semi-auto computer-controlled transmissions with small paddles or buttons to make gear changes. Extensive development has shown that these computer-controlled gear changes are faster and more accurate than any human-manipulated manual transmissions, and can be conducted while under brutal full-throttle racing conditions. F1 cars weigh 1400 lbs and generate 850bhp, so if the system works under such severe flat-out racing conditions the street versions should be just about bulletproof. Besides Porsche, Ferrari also makes extensive use of the semi-auto transmissions in their ultra-high performance street cars.
How does it work in practice? Pretty well. The Porsche Tiptronic system has a standard floor-mounted shift lever and two sets of small rocker switches on the steering wheel. You can leave the transmission in Drive and it will shift itself, or move the lever into Sport mode and use either the floor lever or the rocker switches for all shifting operations.
Basically the car’s computer senses things like road speed, engine revolutions, torque and horsepower output, throttle position, transmission input shaft speed, wheel revolutions, etc. etc. and manipulates the transmission’s internals according to any number of pre-determined and stored “maps” to make seamless up-or-downshifts. Because the electronic and hydraulic systems take up more room in the transmission case, the Tiptronic has just 4 gears instead of the manual’s 6-speeds.
Taking off from a standing start, the computer manipulates things smoothly, giving you a perfect launch every time. As engine revs rise, depending on certain variables, the computer upshifts. Under full-throttle conditions the computer will hold the car in a lower gear until nearly redline, giving the driver optimum acceleration just like a manual-shift Porsche. Full-bore shifts are good but not as hard and fast as with a manual gearbox. There’s always a fraction of a second delay and every shift feels a little soft compared to Porsche’s slick manual 6-speed.
But I don’t like leaving the lever in Drive. Under light throttle conditions the car shifts into a higher gear far too soon, producing sluggish acceleration and resulting in engine lug. The 993 has a 3.6 liter flat-6 engine with plenty of torque, but slogging along at 1500 rpm in top gear shortens the car’s engine life substantially. The computer just doesn’t have the skill of an experienced human driver. The 993 comes alive around 3000 rpm, and loves to be driven in the 3-5000 rpm range for sparkling performance and crisp engine response. Unfortunately the computer isn’t programmed for this kind of sporty driving, and more often than not you’ll find yourself trundling along at lower engine speeds.
The shift switches on the steering wheel are pretty cool, but have a couple of real shortcomings. First, they’re easy to confuse for horn buttons, and you might downshift unintentionally instead of honking. When driving the 993 fast and hard, I use the “9-o’clock-3-o’clock” hand position. In tight turns my arms frequently get crossed up and it’s impossible to figure out which way to press the shift switch. This can be really problematic, as driving the 993 fast is so much fun you tend to do it a lot. Another problem is that switch-shifting down into first at anything other than a complete standstill produces a disconcerting klunk from the drivetrain. Downshifts in general aren’t as clean or intuitive as upshifts, despite all that computer processing power.
The 993 Tiptronic is a purebred Porsche in every way. Build quality is astounding... close the doors and you get that reassuring Zuffenhausen “thunk.” Panel fit is flawless, paint near-perfect, and finally Porsche has revamped the heating/cooling system so that it actually works, and you can actually figure out how to use it. The radio/stereo is dull-sounding, but I feel that’s more due to the lack of interior space than anything else. The cabin is snug, and the passenger’s side seat downright cramped. As with other 911’s you sit down inside the car, close to the road. Much of the objectionable engine noise is gone now that the engine uses hydraulic valve lifters, the very first aircooled Porsche to have them
The ride is pure sports car: relatively harsh, lots of vibration and road feel coming up from the chassis, but this car goes exactly where you point it 100% of the time. Cornering is dead-flat and direct, with virtually no body roll. Porsche extensively revamped the entire 911 platform to create the 993, and the engine/transmission package is now anchored by an enormously strong cast-aluminum bridge running transversely across the rear of the car. The rear suspension is all-new, and that dreaded lift-throttle oversteer has all but disappeared. You can drive this car very hard and very fast with almost complete abandon.
This is a car with a significant downside for the average driver. Don’t even think of this car as a daily commuter or going-to-the-store-for-Huggies-and-brie vehicle. It’s a razor-sharp thoroughbred in a world of plain-jane econoboxes. The 993 is very expensive, high-maintenance, cramped, somewhat noisy, slurps high-test gas, takes 12 quarts of oil at every change, draws attention whether you want it or not, costs a lot to insure and even more to fix. But it’s fast, handles incredibly well, looks like a million bucks and is built beautifully. I feel it’s the very best of the aircooled Porsches, and will become sought-after by collectors and enthusiasts alike.
