nooby tire question

what do the three numbers describing tires each individually mean for example 215/35/18 compared to 225/40/18 thanks

Look up "Size" in Tire Rack's web site.

Then find a "Tire Size Calculator".

The quick answer: section width, aspect ratio, wheel size. The section width is in mm, and is the width at the widest point of the tire (not the tread). The second is aspect ratio in %. If its a 40-series tire, that means the sidewall is 40% of the section width. The last one is the size of the wheel it fits.

The quick answer: section width, aspect ratio, wheel size. The section width is in mm, and is the width at the widest point of the tire (not the tread). The second is aspect ratio in %. If its a 40-series tire, that means the sidewall is 40% of the section width. The last one is the size of the wheel it fits.

so then what size tire would you suggest if i wanted really low profile tires for 18inch wheels

In order to answer the "what size question", one needs to know what the year, make and model of your vehicle is as tire size is related to load capacity.

But a quicker way to get your answer is to look at your vehicle placard. That will tell you what the original tire size and inflation pressure was for that vehicle. The load index is there, too. and your new tires should be at least the same load index or larger. the vehicle placard is usually located on a doorpost or in the glove box.

Hope this helps.