at least once a year. But still check your tire pressure every month just to be sure:)
To replace all the tires on a car with 27-inch rims, you would need four tires.
It depends on how old your tires are and how warn they are. The front tires will wear out first, so if they replace your tires regularly then you can get away with only replacing the front two. If you rotate your tires when you change your oil or don't replace your tires often enough then you will probably want to replace all four at the same time.
As often as they require replacement. If the trailer or drive tires get to 2/32nds, replace them. Steers have to be at least 4/32nds.
not too often unless they dont work
When your tires have 2/32" tread depth left you need to replace them.
Ask the mechanic to inspect the tires when the car is serviced.
You should replace your vehicles tires approximately every 60,000 miles. Or when the tread on the tire is close to all gone.
Firestone, Discount Tire, and Goodyear are all great places to purchase new tires. It is advisable to replace all four tires at once in order for all tires to have similar tread and for the car to be able to grip the road most securely.
Finding new tires to replace tires for winter weather can be done at Costco or Sam's club or by going to the local car dealers or repair shops and buying from them.
6000 miles is the usual recommendation.
Ideally, you should at least replace both front or rear tires simultaneously, but you can get away with only replacing one if the difference between the tires isn't too great.
When your tire treds have gone bald it's time to replace ATV tires. You can also have a qualified dealer look at the ATV. The rules are similar to the tires on your car. You should replace ATV tires when you start to see the tread worn all the way off the tires. You should also replace tires that are showing wear of the rubber itself - cracks, bulges, flaking, etc. as these problems could lead to a catastrophic tire failure during use.