Q: Downsizing tires.

What is important to note when comparing tire sizes is what each of the numbers stands for. The first number denotes the width of the tire. The second number is what is known as the aspect ratio, which denotes the height of the tire from the ground to the bottom of the rim of the wheel. This is sometimes referred to as the "profile" of the tire as well. The last number is the diameter of the wheel that the tire is designed to fit. In your case, the new tires you have should fit your tires just fine as there is a minimal difference in the sizing between the two. One thing to remember, however is when changing tire sizes, your speedometer may be slightly inaccurate due to the change in tire size relative to the normal wheel rotation. It may not be very noticeable in your case due to the small change, however it is possible it may be affected slightly. In the event you need to correct this, you can have your speedometer re-calibrated to the new tires size.