[BHarvey]

I remember a thread a while back about this and thought I'd give more input.
A non o-ring chain is lighter and has less friction than it's o-ring counterpart.

At Road Atlanta back in the 90's, the difference was worth 7 mph.

Now, at the time I was always using one of the crappy (which one isn't) spray lubes, and have enough knowledge about it now that I am using used motor oil.

You ask 'WHY' used motor oil, well, to keep a non o-ring chain very well lubed it takes more effort than the normal person (non anal) can give, so an auto oiler is where we need to be.

Gear oil is very good for non o-ring chains, but is very thick and that is when it is 80+F. SAE40 which is equal to a 90 gear oil at 212f, is even too thick for a 'vacuum release' oiling system at 80F.

So, a multi-weight 10w40, 15w40 or 20w50 can work out very well even when cold. The best reason for using it is that you aren't using brand new oil on a total loss system. Recycling, green, whatever.

There are several auto oilers on the market, but you can build one much cheaper, and the FE benefit looks to be worth 10% over using spray lubes which gunk up the chain. All the chains/sprockets I've been through before now have been using one of the various spray lubes, that gunk and kink up the chain.