High Quality Content by WIKIPEDIA articles! The S65 is a naturally-aspirated DOHC 32-valve automobile V8 engine from BMW. Derived from the BMW S85 V10 engine used in the M5/M6, it shares the same basic architecture and aluminium construction. It was introduced in the E92 M3 as a replacement for the S54 straight-6. The engine was chosen as International Engine of the Year for the 3.0 to 4.0 L category in 2008 and 2009. The S65B40 was developed as a result of increasingly stringent Euro V and California Air Resources Board (CARB) emissions regulations. The S54 engine had reached the end of its development potential, making it clear a new engine was needed. The S65 shares the same 92 mm bore and 75.2 mm stroke cylinder dimensions with the S85 V10, along with the Double- VANOS variable valve timing system and 12.0:1 compression ratio.