So why not run it this way all the time? Well, let's not forget the freezing point. While the pressure cap trick gives us a higher boiling point, it does not a thing for freezing point. If your area doesn't get down to negative temperatures in the winter, you can run a decreased ratio of antifreeze to coolant if you like all year round. However, I'd still run 50/50 in the winter. The good news is, in the winter, there's less need for excellent cooling as air intake temps and ambient temps help you out a lot more than in the summer.