I saw lower temperatures (by up to 5 degrees celsius) across my heat exchangers. I did still run 100% used veggie oil. In the spring I had one clogged aux tank filter, it was a year and something like 20,000km old. I had a mind to change it already, I had hoped that it would last for the rest of that trip. Quick fix in a canadian tire parking lot, and once I got a new filter on, no problem.How has the VO conversion worked out over the winter. Any problems?