In the glow fuel issue, I did some research and made several phone calls and enquiries A few months ago. I found every manufacturer that revealed formulas only used 1% castor in their synthetic castor blends. None would give an exact description of their synthetic oils. Then I checked out Sig. I used to buy it at my LHS but they dropped Sig a few years ago. Sig is straightforward about their ingredients and contains more castor in their blends. I ordered some 1/2 A 35% nitro 25% castor and some 10% nitro 20% synth/castor blend. The blend clearly states 20% total oil, 10% castor, 10% Klotz. My LHS gets it for me for $19 per gallon. My engines run amazingly well and I have no doubts what I'm getting when I buy it.