Here is what I do: ALWAYS start on diesel. Never burn WVO until engine is fully warm. Always run on diesel the last couple of miles before shutting down. I run WVO (extremely well filtered) in the front tank. In the winter, sometimes I mix in some K2 10-20% below freezing to thin it out. I have a single piece of extra equipment, a flat-plate heat exchanger to heat the fuel before the lift pump. I put a temperature gauge on that and see 160 degree fuel temps. Works good for me. (PS I have a full conversion on my Mercedes, and a similar conversion as my truck on my boat which has a cummins 4BT). One thing people with fancy conversions fail to realize, and that is if you can pump it freely into a hot IDI engine, you are good to go. The heat just helps you to be able to pump it in cold weather. A lot of people refuse to believe, but I can promise you it works very well. But only use high quality wvo.