seconds vs. 47.3 seconds by Grand Prix driver Mike Parkes on his 3-liter V12 Ferrari 250 GT. A brief chronology of the most notable changes made to the 230 SL: 10/1963: First 230 SL with automatic transmission. 09/1964: Spare tire well removed, tire mounted horizontally. 11/1964: Optional tinted/thermal glass and new soft-top with steel bows (distinguished by missing chrome trim on the outer trailing edge). 04/1964: US models with radio Becker Europa TR instead of Europa TG. 08/1965: Some harmonization with new W 108/W 109 sedans, incl. new floor panels, combined brake and clutch fluid reservoir, boot light and interior changes. US models with hazard lights. 03/1966: Mounts for three-point seat belts added. 05/1966: Optional ZF 5-speed manual transmission; rare and now very desirable. 250 SL (1966–1968) The 250 SL was introduced at the 1967 Geneva Motor Show. Production had already commenced in December 1966 and ended in January 1968. The short one-year production run makes the 250 SL the rarest of the W 113 series cars. The 250 SL retained the stiffer suspension and sportier feel of the early SLs, but provided improved agility with a new engine and rear disc brakes. Range also improved with increased fuel tank capacity from to . Like its predecessor, the 250 SL was offered with a 4-speed automatic transmission, and 4-speed or ZF 5-speed manual transmissions. For the first time, an optional limited slip differential was also available. Of the 5,196 250 SLs produced, more than a third were sold in the US. The main change was the use of the M129.II engine with increased stroke, increased valve ports, and seven main bearings instead of four. The nominal maximum power remained unchanged at , but torque improved from to . Resiliency also improved with a new cooling water tank ("round top") with increased capacity from to , and a standard oil-water heat exchanger. The wider power band of the 250 SL resulted in noticeably improved performance, as the 230 SL engines rarely produced more than in practice. California Coupé The 250 SL also marked the introduction of a 2+2 body style, the so-called "California Coupé", which had only the removable hardtop and no soft-top: a small fold-down rear bench seat replaced the soft-top well between passenger compartment and boot. Midlife improvements In August 1967, a number of additional changes were incorporated to accommodate stricter safety regulations and US emission laws. The safety