Around 1967, the engine received a displacement increase and the model became known as the 250SL.

Earlier engines later received this type as they became due for re-boilering.

The 1970 models were introduced in October 1969, received the L24 2.4-liter engine and a 4-speed manual.

During the rebuild, the engine also received a cosmetic makeover.

The audio engine received a massive overhaul to upgrade the quality of sound effects.

The engine received a forged steel crankshaft in October 2003.

The engine received larger fuel injectors and an increase in compression to 8.6:1.

The 4-cylinder engine received a 12 hp (9 kW) gain late in the 1989 model year.

In August 2001 this engine received an additional four horsepower.

Spock had marked this as their limit until engines received a final balance.