The Mercedes-Benz W113 series was the successor to both the 190 SL and the legendary 300 SL and as such a bit of a disappointment at the time. Regular Mercedes customers were reluctant to buy the car; it was too small to be impressive and too slow to be a sportscar. According to contemporary reviews, the new design by Paul Bracq with its low waistline and big greenhouse windows lacked the finesse and elegance of the top class Italian sports cars. Also a optional removable hardtop (whose distinctive roofline earned the nickname "pagoda") was considered too boxy.
Production began in 1963 with the 230SL model. The running gear, borrowed from the four-door Type 220 SE sedan, was adapted to meet the needs of the roadster. The 2306 cc inline-six engine itself was a masterpiece with multi-port fuel injection using a mechanical pump system adapted from the diesel motors. Engine developed 150 hp at 5500 rpm, offering 200 Nm of torque at 4200 rpm, 0 to 100 km/h took 9.7 seconds. The 230 SL’s highly sports-oriented tuning meant the car enjoyed getting up to speed – low revs were simply not its thing at all. The 230SL sported front disc / rear drum power assisted brakes. These models were commonly 4-speed manual transmission cars, but a 3-speed automatic transmission was also available and was popular for U.S. market cars.
At the end of February 1967 the 230 SL was superceded by the slightly larger-engined but otherwise almost identical 250 SL, true to the motto “nothing beats displacement like more displacement”. Now the capacity was 2496 cc, power output remained at 150 hp. The 250SL was basically a one-year model and is the rarest of the W113 cars. The main changes beside the use of a 2.5 liter motor was the addition of rear disc brakes. The 250SL retains the stiffer suspension and sportier feel of the early SL's but provides significantly improved performance, especially given the engines wider power band. The 250SL was also available (rarely) with a ZF 5-speed manual transmission.
Less than a year later, the 2.8 liter 280SL (2778 cc, 170 hp) was introduced in December 1967 and continued production largely unchanged through 1971 when the W113 series was replaced by the entirely new, and substantially heavier, R107 350SL/450SL. Since then the SL-series transformed from sporty and elegant to big and luxurious and lost most of its youthful appeal.
Taking all three “Pagoda SLs” together, a total of 48,912 units were built up until March 1971.
Production by model:
1963-1967 230 SL: 19,831 units
1967 250 SL: 5,186 units
1968-1971 280 SL: 23,885 units
Sources: DaimlerChrysler Heritage; wikipedia.org; ritzsite.demon.nl
Edit: corrected 250 SL engine displacement