I think Redline caters to customers that never really had a use for a 0w oil. They claim hp gains with their oil as it is without going to a 0w weight. I was really surprised to see them introduce a 5w-20 oil recently, but I am sure most of their sales are in higher viscosities. Maybe if there is enough demand expressed to them they could develop a 0 weight. good question though.
When I first saw 0W-30 oils in the stores (must be 2+ years ago or so) I emailed Red Line and asked them why they don't have such an oil. The response I got basically was that RL serves the lower viscosity/cold temp oil market with their 5W-30 oil so they didn't feel it was necessary to formulate a 0W-30.
Their position may have changed since but that was what I was told then.
Patman, I don't have an answer to your question, but Motul 8100 0W-30 and 0W-40 are 100% Ester based. They are not that expensive either, CDN$60 for a 5L bottle of the 8100 0W-40, so less expensive than Amsoil's S2000 0W-30.
If they were hard to manufacture, Motul would probably sell them for more than their current price.
They make some very thin race oils. Their SAE 10 is a 0w10. They also make a 2 and 5 which is even thinner.
Their web site has physical properties for these oils.
[ March 22, 2003, 10:22 AM: Message edited by: satterfi ]