You put them wherever they are needed. If the threads are bare then they need replacing by law. See a car professional.
If possible, put the best tires at the back. When braking(hard), the weight at the rear of the car will be momentarily reduced, making it easier for those wheels to break free and skid. By having the tires with the best grip at the rear you reduce that risk a little.
The new tires should be placed on the rear axle to lessen the risk of hydroplaning.
In my opinion the new tires go up front. The steering tires need the grip.
I am no expert, but I would put only two new tires on my front wheel drive car, I always put the best pair in the front. I am not good with cars but 2 be honest i think you should put the 2 new tires on the back because the back wheels are the 1s that move the car and they need better mobility
take the tires off and old brakes off and put the new ones on. put the tires back on and drive!!
yes they should be the same size otherwise the front and rear tires will be turning at different speeds and could ruin front axle or transfer case.
Generally when purchasing tires for a vehicle how many you should purchase depends on the type of vehicle you drive. For all wheel drive or four wheel drive vehicles it is recommended to replace all four tires at a time to be sure all tread patterns match. For front or rear wheel drive vehicles the tires on both the front and rear axle should match each other and can be purchased in sets of two if needed. Tire rotation is generally done to maintain the tread life on your tires and tread life warranty from the manufacturer if any. Without rotating your tires they will suffer from excessive treadwear that can lead to early replacement. Tires should be rotated at intervals of every 6,000 to 7,000 miles or every second oil change to maximize tire life, rotating tires is designed to extend your tires life and won't help if your tires already need replacing.
Good idea TO DO SO
I have always wondered that and can see no logical reason. I almost always put new tires on front so I have better steering. Unlike many people, I also keep a very close eye on my alignment and have it checked and adjusted at least every 2 years.
Replace the ones with the least tread left. Put the new tyres on the rear.
You sould have the new tires mounted FIRST, then have them do the alignment at the same visit.
Some of the new models have threads and lock nuts on each end. Loosen the lock nut on each end. Take a ruler (the folding wooden ones like carpenters use is best) and measure the distance between the front tires on the front side of the tires. Now measure the distance between the front tires on the back side. The back side should be about 1/4 inch wider. The drag link is made so when it is turned it will adjust both sides at same time. Recheck measurement. If OK, tighten lock nuts.
You should check to see if your tires are bald and are not durable anymore.