Fourth Generation (1974-1977)

Both the 911T and 911E disappeared from the 1974 lineup as the 911 got its most serious makeover yet. Taking their place were a letter-free 911 and, finally in America, a Carrera. All featured versions of the 2.7-liter engine introduced on the Carrera RS and new styling to accommodate energy-absorbing bumpers mandated by U.S. regulations.

The new body-colored bumpers made the '74 911s look more contemporary and featured black rubber boots at the ends that looked like bellows. All the engines also adopted electronic fuel injection as emissions regulations grew even tighter. That put the output of the 911's 8.0-to-1 engine at 143 horsepower, and the 911S' and Carrera's 8.5-to-1 power plant at 167 horsepower.

The U.S. Carrera carried the same bodywork, wheels and tires as the European Carrera RS, but had to stay with the 911S engine to meet emissions. Other changes to all 911s included new aluminum and magnesium suspension components, new front seats with integrated head restraints, some other interior revisions and a rigid fiberglass top for the Targa.

Porsche eliminated the base 911 for 1975, narrowing the line to just the 911S and Carrera with one engine. More modifications were made to deal with emissions regulations and that hacked the output of the 2.7-liter six down to 157 horsepower in every state except California, where it was rated at just 152 hp. These were not the quickest 911s ever.

Except for a new rubber-rimmed "whale tail" rear spoiler on the Carrera, the '75s looked much like the '74s. But there were 1,500 special "silver anniversary" edition 911s created to celebrate the company's first quarter century. All the silver anniversary cars were painted, well, silver.

But the big news for '75 was taking place in Europe with the introduction of the fabulous Turbo Carrera that didn't quite make it to the United States that year. But it would for 1976.

The 911S was the only normally aspirated 911 for '76 and, virtually unchanged from '75, it was easy to overlook. In fact it was a joy to overlook as all eyes fixated on the 234-horsepower 930 (Porsche's internal model number) Turbo, which had one real, live turbocharger blowing into its big 3.0-liter engine.

With even bigger fender flares over humongous (for the time) 215/60VR15 front and 225/50VR15 rear tires, a deep chin spoiler, headlamp washers and that whale tail spoiler, the 930 was an instant classic. Surprisingly, because of the Turbo's torque output, the only transmission aboard it was a four-speed manual. Car and Driver had the $25,850 Turbo blitzing to 60 mph in just 4.9 seconds and topping out at 156 mph — simply astounding performance for a time when most cars were strangled by primitive emissions controls. The 911 Turbo Carrera is one of the few great performance machines of the 1970s.

Except for a move of the Turbo from 15- to 16-inch wheels and tires, the 1977 911s were very much carryovers from '76. The front quarter windows no longer opened, the ventilation system was revised for more output, and there were new vacuum brake boosters, but otherwise status quo was maintained.