I have been running Mobil 1 synthetics over 30+ years, probably closer to 40 years. I have over 700,000 miles on my diesel Jetta. I happen to use Shell T6 in the truck but it only has 200,000 miles on it. T6 in my little 870 Deere. Works fine. The few days it gets cold with snow the tractor starts right up with no intake heater turned on. Of course cold and snow where I live means it might be 20F. If you want to test, pour a cup of dino oil in a two cup glass container. Pour a cup of synthetic oil in a 2 cup glass container. Stick in freezer overnight to see how they pour at 20F. I assume the synthetic will pour a bit easier that the dinosaur oil.