maybe stupid question?

No. The 13 in the tire size is the rim size it fits on.

You want to keep the outer diameter of the tire about the same as stock so that the speedometer and odometer will read accurately. There are tire size calculators on the internet that you can use to determine what other size tires you can run on your stock wheels and maintain the correct rolling diameter.

JazzMan

No. You have 13" rims on your car. That size is for 14" rims. Use the size in the owner's manual. It's possible to go slightly wider.

You can put various tires on your 13" rims. Depending on what size you select, it can affect your speedometer, odometer, and perhaps the ABS if you have that. Some vehicles will allow you to increase the rim size to a 14" rim. It depends on how much clearance there is around the wheel wells. You would buy new rims and tires in this case. You could stop by the tire shop and see what they think would work for you. They are usually glad to sell new tires and rims and they would have the opportunity of actually seeing the mystery vehicle you are driving.