Date registered: Oct 2008
Vehicle: 1959 190, 1961 190SL, 1967 250SE 4Spd, 1968 220D 4spd
Mentioned: 1 Post(s)
Quoted: 5 Post(s)
Low Engine RPMs Stressful on old MBZ engines?
I've heard it said several times that low-rpm situations under load are harmful to the old Mercedes engines. Engines in the era of M121/130/180, etc. For instance, shifting early into 4th gear, at say 25mph, then accelerating away to 50+ after that shift. Is this bad? I've heard it is, but have never heard the mechanical explanation for why this is so. Would love to hear an explanation or theory.
When I first started driving, I always assumed lower rpms are more gentle on the engine, figuring less camshaft movement, less wear, less heat, etc, so this is contrary to my logic.