If you have owned your Lexus RX300 SUV for a while, you may want to change its look and feel. Maybe you think that the vehicle sits too high on the road, or you don't like the way it handles during cornering, or you don't like the ride. If your tires are reaching the end of their useful lives, you might think about replacing them with wider tires.
Check the owner's manual for optional tire and rim sizes for your vehicle.The standard tire size for the RX 300 is 225/70R16, and optional tire sizes range up to 255/35R22. The first number in the tire size is the width in millimeters. The second number is the aspect ratio or the ratio of the tire's height to its width; and the third number is the rim size. The widest tire that you will be able to place on your RX300 is 255 mm, and the largest rims will be 22 inches.
Visit local tire retailer and purchase the tires and rims you selected. The rear struts on your RX300 will not allow you to use 255 mm tires with the 16-inch rims that are standard on the RX300, so you will have to upgrade to at least a 17-inch rim if you decide to install that size.
Place the first rim on the ground or a flat surface with the outside facing up. Put one of the tires on top of the rim with the outer sidewall facing up and and press down on the tire to get as much of the tire on the rim as possible. Spray WD-40 on the tire beads and rim for lubrication. Use a crowbar to pry the remainder of the tire onto the rim, beginning with the low-side tire bead. The beads run along the inside edges of the doughnut hole on each side of the tire. Repeat the procedure for the other three rims and tires.
Take the wheels to a local gas station and inflate them to the manufacturer's recommended tire pressure. There will be loud noises as the tires seat themselves in the rims. Use a jack and lug wrench to remove the old wheels and install the new ones.
