Demarpaint, Mr MMO himself, MMO certainly isn't a competitor for oil in my engine. What additive or additives did the oil formulaters leave out that it warrants the usage of MMO??? I'm going to quote Caterham on one of the possible effects of MMO::
"With MMO's KV100 of 2.64cSt the main effect as far as I can see of adding MMO to engine oil is too reduce the viscosity.
Added to a 10cSt 30wt oil at the maximum dosage of 25% would give you a very light 20wt 7.0cSt oil.
Added to a heavy 30wt oil like GC will still reduce the viscosity to that of a 20wt 8.0cSt oil.
Added to a 40wt like M1 0W-40 would still result in a 20wt 8.6cSt oil.
What I would really like to know is what the KV40 spec' is for MMO. This would provide the viscosity index which I suspect it is quite low, in the 100 area. If I'm right, not only are you reducing the operating viscosity of the oil when you add MMO but also the oil's VI. If that's the case, one would be better off adding an ultra high VI (216) oil like the Toyota 0W-20. In so doing, you'll be reducing the operating viscosity but also increasing the oil's VI, thereby reducing the start-up viscosity disproportionately.
Using the GC example, 25% Toyota 0W-20 would still leave you with a reasonable heavy 11.1cSt, 3.3cP HTHSV 0w30 oil but with the VI improved from 166 to about 178."
---Caterham