WHICH IS WHICH

All those engines, all those codenames

The 107 series started life as the 350 SL, powered by the 200bhp M116.982 3499cc V8, with Bosch D-Jetronic fuel injection. It was produced until 1976, then replaced by the M116.984 with K-Jetronic fuel injection for 195bhp, and offered until March 1980. For the USA market, from June 1971 the 350 SL 4.5 (later called the 450 SL) was launched with emission controls that would have seriously hampered the 3.5-litre. Codenamed M117.982, and with 4520cc and D-Jetronic fuel injection, it developed 195bhp (reduced to 180 in California, choked by catalytic converter and exhaust gas recirculation). The European version made 225bhp. The same engine became the M117.985 from 1976 to 1980, with K-Jetronic injection, and developed 217bhp in Europe and 190bhp in the USA.

In the meantime, Europe was strangled by increasing fuel prices, so from 1974 Mercedes offered the M110.982, a 2746cc twin-cam straight-six with D-Jetronic injection, offering 185bhp. As the M110.986 with K-Jetronic injection, it made 177bhp from 1977 to 1981, and up to 185bhp as M110.990 from 1981 to 1985.

From May 1980 a new series of engines, all with K-Jetronic fuel injection, was donated by the recently introduced S-Class W126. The M116.960, a 3818cc V8 with 218bhp in Europe and 160bhp in the USA, was in use from May 1980 to September 1981, when it was replaced by the M116.962 of 3839cc, with 204bhp in Europe and 160bhp in the USA; that lasted until 1985. In September 1981, for the European market only, the now-iconic 500 SL was launched with the lightweight M117.962 V8 of 4973cc, with K-Jetronic injection for 231bhp. It evolved into the M117.964 from September 1985, with KE-Jetronic injection for 245bhp (or 223bhp when paired with the catalytic converter).

The biggest engine of the lot arrived in November 1985, for the US-market 560 SL: the M117.967 V8 of 5547cc, with KE-Jetronic injection and 245 bhp, down to 223bhp with a catalytic converter. At the same time, completing the European range with the 300 SL, came the new 2962cc M103.982 single-cam straight-six with KE-Jetronic injection, which made 188bhp (180bhp with catalyst). The ultra-rare 420 SL featured the M116.964 V8 of 4196cc, with KE-Jetronic injection, for 218bhp (203bhp with catalyst).