Porsche 911 Carrera 4 (964) ~ 1989-1993
But there was no getting away from the fact that the 911 was getting long in the tooth. Competition from Japan, in particular, was having an effect on sales, especially to those who wanted a prestigious sports car, but who didn't want to put up with the compromises offered by the 911.
Porsche knew that if it was to survive it simply had no alternative but to update the 911. This brought, in October 1988 for the 1989 model year, the radical 911 Carrera 4. This was known within Porsche itself as the 964, and this designation is still widely used by enthusiasts.
The Carrera 4 featured a four-wheel-drive transmission system based on that of the 953-model Paris Dakar Raid car of 1983. Not only did this new transmission go a long way toward eliminating the 911's previously rather wayward handling, but it also proved to the buying public that the car was now bang up to date.
But there was much more to the new 911 than four-wheel-drive. Indeed, Porsche's press office claimed that the 964 was no less than 87 per cent new compared to the previous Carrera 3.2.
The majority of the changes were mechanical. Out went the old torsion-bar suspension to be replaced by conventional coil springs. The brakes were uprated and, for the first time in a 911, ABS was standard.
The engine was based loosely on the earlier 3.2-litre unit, but was considerably modified. The capacity, was increased to 3.6 litres by altering the bore and stroke and fitting new pistons. Output rose from 231bhp to 250bhp at 6100rpm, while the torque increased from 284Nm to 310Nm at 4800rpm.
Twin spark plugs per cylinder were ignited by dual distributors, to improve the combustion efficiency and thus allow the ignition timing to be retarded, while at the same time allowing the use of 95-octane fuel with an increased compression ratio of 11.3:1. A new Bosch Motronic engine-management system controlled both the ignition and fuel-injection systems.
New cylinder heads featured ceramic liners for the exhaust ports. These were claimed to reduce the head temperature by some 40 degrees Celsius, thus eliminating the need for sodium-filled exhaust valves, which had been a feature of the 911 engine since the beginning.
The engine was mated to an all-new G64 gearbox with a centre differential for the mechanical four-wheel-drive transmission.
The four-wheel-drive required significant changes to the bodyshell. The luggage compartment was now deeper at the front than before, but the rear was occupied by both the fuel tank (which had to be raised to make room for the transmission) and the turrets for the coil springs.
The 964 kept most of the previous car's body panels, but was updated with integrated deformable bumpers. In addition the front and rear screens were more flush-fitting and this, combined with a revised floorpan and a rear undertray, reduced the drag coefficient to just 0.32.
Another aerodynamic change was the rear spoiler. The whaletail of previous 911s had fallen out of favour with buyers, who now preferred cleaner, more subtle lines. But the rear of the car still needed downforce at high speed, so Porsche developed a retractable spoiler. This lifted when the car reached 50mph, and then dropped down again at a little over walking pace. The raised tail also improved engine cooling.
Inside, the changes were more subtle. A larger centre tunnel was required to accommodate the four-wheel-drive transmission, and this also reduced the length of the gearlever. The dashboard was basically the same as before, but came with new instruments with built-in warning lights.
There was an electronically controlled heating system with conventional dashboard-mounted controls that were easier to use and more effective than the old system between the seats.
The first 964 Carrera 4s had flat-faced Design90 wheels, but in 1992 new Cup wheels were fitted. At the same time, the 'elephant ear' door mirrors were replaced with more shapely 'teardrop' items.
The 964 Carrera 4 was undoubtedly a great step forward for the 911 but some early cars suffered from oil leaks and other reliability issues. These were quickly addressed by Porsche but the 964 never really recovered its reputation and, once the 993 came along, prices dropped and the 964 became somewhat forgotten. Yet buy a good one and you'll have a modern 911 with classic looks for a very reasonable price.