BMW S50 engine

Specifications

The BMW S50 engine stands as a milestone in BMW M’s performance history, engineered to deliver a pure, naturally aspirated driving experience rooted in motorsport technology. Designed for the E36 M3, it uses a strong cast-iron block paired with a lightweight aluminum cylinder head, ensuring durability while supporting high-rpm performance. One of its defining features is the use of individual throttle bodies, which provide exceptionally sharp throttle response and precise airflow control, giving the engine its immediate and engaging feel. Offered in 3.0-liter and later 3.2-liter versions, the S50 introduced advanced innovations such as double VANOS variable valve timing, improving low- and mid-range torque without sacrificing top-end power. 

With a thrilling redline approaching 7,600 rpm, a distinctive mechanical sound, and linear power delivery, the S50 earned a reputation for reliability, balance, and driver involvement, making it one of the most respected naturally aspirated inline-six engines ever produced by BMW M.engines ever produced by BMW M.

Engine Variants

S50B30

The S50B30 was the original engine introduced in 1992 for the E36 M3 sold outside North America. It is a 3.0-liter naturally aspirated inline-six featuring individual throttle bodies (ITBs), a cast-iron block, and an aluminum DOHC 24-valve cylinder head. The engine uses single VANOS on the intake camshaft for improved mid-range torque. It produces 282 hp (210 kW) at 7,000 rpm and 320 Nm (236 lb-ft) of torque at 3,600 rpm, with a 7,200 rpm redline. Fuel delivery is handled by Bosch Motronic M3.3, and the engine is known for its high-revving character and sharp throttle response.   A limited S50B30GT version was produced for GT racing, featuring revised camshafts, improved oiling, and increased output of 295 hp (220 kW).

S50B30US

The S50B30US powered the 1994–1995 U.S.-market E36 M3 and was significantly different from the European engine. While still a 3.0-liter inline-six, it was based more closely on the standard M50 architecture. It lacked individual throttle bodies, instead using a single throttle body, and did not use VANOS. The engine produces 240 hp (179 kW) at 6,000 rpm and 305 Nm (225 lb-ft) of torque at 4,250 rpm, with a 6,500 rpm redline. It uses Bosch Motronic M3.3, prioritizing durability, emissions compliance, and lower maintenance costs over high-rev performance.

S50B32

The S50B32 was introduced in 1995 with the facelifted E36 M3 and represents the most advanced version of the S50 family. Displacement was increased to 3.2 liters, and the engine gained double VANOS (variable timing on both intake and exhaust camshafts). It retained individual throttle bodies, a forged crankshaft, and upgraded internals. Output increased to 321 hp (236 kW) at 7,400 rpm and 350 Nm (258 lb-ft) of torque at 3,250 rpm, with a higher 7,600 rpm redline. The S50B32 also featured a six-speed manual transmission, improved cooling, and stronger oiling, making it one of BMW M’s most celebrated naturally aspirated inline-six engines. 

Frequently Asked Questions