As a matter of fact, rotating your tires is (or can be) dangerous.
Here's why. After a period of service, the left front tire has bedded itself into the particular suspension alignment foibles of your left front suspension/wheel. If you now put the left front tire on the right, now, that tire does not "sit properly" on the road, and it remains so until it beds in and wears itself in to the foibles of the right front wheel.
Once the tire is bedded in, its contact patch will be more or less in the middle of where the suspension engineers designed it to be. But during the bedding-in period, the contact patch can be displaced as much as an inch to the side of where it was designed to be. (Of course, you get no sign that this is happening.)
If you now have a problem (e.g a slippery road) the chances of the car skidding into a spin are considerably increased.
So, never rotate your tires. If your left and right fronts wear at different rates, don't swap the tires over -- get your alignment checked. If you do swap, you'll be more likely (for a few weeks) to skid on a slippery road.
Another benefit of not rotating your tires (i.e not rotating them front to rear) is that, on most cars, the fronts wear faster than the rears. So you just buy one pair of new tires.
Of course, as everyone knows, if you just buy one pair of new tires, you put them on the back. Whatever your make and model of car, you always put your new pair of tires on the back.
Buying just one pair of new tires (and putting them on the back) evens out the dollar expenditure on new tires over the years, plus it helps ensure that, if you get into tire-skid conditions, it's the fronts that break free first, not the rears. A rear-wheel skid (where the rears break free first) is ten times more likely to put you in the path of the oncoming truck than a front-wheel skid.
Terrible advice.
Does not take into account manufacturers change compounds, and that the tire degrades from UV and ozone with age. Running one set of brand new tires that have more grip and an older set that has less grip is not ideal. The front brakes do 70% of the braking, yet you think it's a great idea putting the tires with the lower coefficient of friction up front, increasing your stopping distance. There's a thing called ABS that come on modern cars that mitigates tires from skidding, so the probability of locking the rears is very low. Having a car that has the same coefficient of friction on all 4 corners makes more sense than having a different coefficient of friction at the front and rear unless the car was designed to run different sized front and rear tires. Left and right fronts wear at different rates for various reasons. Most front drive cars do not have a limited slip differential, so the single tire that drives the car wears a bit faster than the other.
What happens if the manufacturer discontinues the size or entire series of tire because a new design comes out? BF Goodrich has been using the Radial TA name for several decades. Do you think a Radial TA from 5 years ago is the same as a new one? What do you do with your two tires with 7/32nds of tread? Mismatch pair? Finally, very few shops rotate from side to side like you are suggesting since a fair number of tires are unidirectional. Pedestrian tires like the Michelin Hydroedge are an example. Front to back is what they do for cars with the same size front and rears.
It will also cost you an arm and a leg to match the tires on your car if it is brand new. Manufacturers request a specific compound for the tire, which will be different than a replacement tire. New factory tires for GM have a TPC code for the make and model of car the tire has been designed for. BMW uses a star, Mercedes uses Mo and Porsche uses N. Replacement tires using the same name and tread pattern do not have a code and are a compromise compound designed to work for a wide variety of cars.
Nitrogen is only necessary if tires experience extreme temperatures, such as airliners and military jets that go from minus 56 to high temperatures on touchdown or in high performance racing cars like NASCAR or Indy.






