All of this talk about oil's and various mixtures got me to thinking about some other "conventions" that have been around a very long time.

Firstly there is the amount of oil we put in our fuels - 20% 25% 33% (old English diesel field 1:1:1 mix) and so forth. Recent use of different materials has seen the suggested percent of oil becoming lower and lower right down to 5% with most of the common off the shelf glow fuels being around 18% these days. Time after time the comments you will read when others describe their mixes is to always have some portion of the oil as Castor oil to help in the event of a lean run, to provide that extra bit of protection. Manufactures have a need to be conservative to keep their customer's engines running well, sport fliers want to keep their equipment running well for a long time; racers, well that's something else altogether. I used to build planes to have crash survivability and they where built tough and heavy. That is until I realized that I should be building them to fly instead. Does some of this same mentality apply to the old conventions of type of oil and percentages in our mixes?

I tried to do some ready on synthetic oils and didn't really find a good answer to use them other than our engines run cleaner on them but still castor has some benefit in fuels with synthetic oil. But what mix, how much is optimal. Of course that question is made difficult because we have engines with Ball Bearings and those with plain bearing crankshafts; however, the connecting rod ends are plain bearing and do require proper lubrication in order to survive.

And what of our diesel fuels using kerosene. If we choose to use a synthetic oil, do we really need one that will mix with alchohol is one that mix with gas/kero just as good? The use of ashless aviation engine oil as Andy has describes has merit but is not as easily obtained as the better synthetic or non-synthetic 2 cycle engine oils a lot of which (according to manufacturers we sites) usually contain a lot of additives to promote clean burning.

And just what is Marvel Mystery Oil. I have been using in small percentage in my diesel mix without ill effect. Seems to run cleaner and I am not the only one to use this. A quick search will revel quite a few using Redex which I belive is the same the thing. I haven't found out what it really is but many claim it be primarily detergents. Your guess is as good as mine.

Trouble with synthetics is that there is lots of choice Amsoil, Motul, Klotz, etc. But which one?

So who knows about these oils? what do you think?

I can see that I will have to try some of these fixings and see for myself, details as they develop.


cheers, Graham in embrun near Ottawa Canada.