[fluoridation]

You're not actually saving anything in the long term, though.

Let's say you start with brand new tires on both wheels. Let's further suppose that you completely wear out your rear tire in 1 year and your front tire in 4 years. If on the first anniversary you rotate and place the new tire in front, you'll need to repeat the procedure after 9 months, and then every 9 months after that. On the 4th anniversary you'll have bought 5 tires: on the 12th, 21st, 30th, 39th, and 48th months. If you simply replace each tire as it wears out without any rotation, on the 4th year you'll have bought 5 tires, 1 to replace the front tire once and 4 to replace the rear tire 4 times.

[matsemann]

True. What you do have is a more consistent / good front tire, which is important for handling curves in wet weather. So still worth doing, instead of riding with a front tire on its last 20% of life.

[fluoridation]

IME as long as the tire is not flat there's no difference in handling between a new and a worn front tire, at least on asphalt.