I run XD35W40 synthetic in my Dodge diesel year round with excelent results. I also have a 4L jug of 0W40 Polar Plus (UFA) synthetic collecting dust. Any thoughts or concerns about changing my little B5001 to synthetic oil? It would definitely help when cold starting but this is an older unit and I don't want my main seals to start to leak. Stick with the dino lube or go with the synthetic?