Thanks. as you say though, not a full explanation, more of a "claim". It talks about being able to run at high engine speeds sooner. I wonder if that's what makes them feel able to claim a faster warm-up time? So, not really a property of the oil, directly, but indirectly, it lets the engine fire-up cold and go to higher revs instantly, without damaging itself - which it might with more conventional oils until they'd thinned-out enough to work properly? Many years ago (more than 50!) I think it was a problem for Reliant, who sold their engines to companies making fire pumps. The poor little things would be expected to fire up and just straight to 4500-odd revs (pretty much max power) instantly, from cold and run there constantly. They had problems with "cold seizures" but if they increased running tolerances, they just drank oil and smoked like chimneys!Not a full explanation, but from the Motul datasheet (attached) ...
@Burnerman - what engine speed does yours go to, on startup? Does it vary?