Not really that I have noticed. Good oils are good oils & bad oils are bad oils... They seem to pretty much work to the same degree in either inlines or twins... I have had some experiences where the extra heat of a twin like the RC51 (notorious for running hot) would break down the oil quicker & effect the shifting & clutch engagement & found that heavier oils seem to prolong this from happening, but that is to be expected. As far as the Maxima oil goes. I cannot recall specifically testing their oil. I have tried their rather expensive brake fluid though which I personally think sucks since a $3.00 bottle of Valvoline Synpower from Autozone works better, gives you more brake fluid & if I am not mistaken also has a higher boiling point than the Maxima brand, but I digress & certainly don't want to get into a discussion of all things fluid or next we'll be discussing the merits of chain wax vs Chain lube vs WD-40 :wink:
I did some testing a few years back on octane & oxygenated fuels & I am sure it is nothing you don't already know about, but you can read the results here if you're bored with nothing else to do http://www.rc51.org/fuel.htm In direct answer to your question, no I've not tried any of the new fuels from VP (U4.1 or MR10) & to be quite honest probably won't be doing much more testing like that as I am just doing trackdays now & don't feel the need to spend that kind of money for a few tenths of a second in my lap times. With my limited budget pump gas is my friend