Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - driving on 4 narrow spare tires (or similar) to reduce rolling resistance

mans · 12-26-2011, 02:13 PM

the size of our tire footprint is almost all decided by the first number.

185/70/R15 tire will be 185 mm wide.
185/85/r15 tire will also be 185 mm wide.
the '85 will be a little taller but the footprint will be the same size.

185's are the narrowest you will find in a tire store today.

I have managed to find 125's from a supplier that sells to people who are restoring vintage vehicles and many really old ones had narrow tires that you don't see today.
the thickness of the tread is 2.75" wide instead of almost double that on my 195/70/R15's.

12-26-2011, 02:13 PM	#3 (permalink)
mans EcoModding Lurker Join Date: Dec 2011 Location: usa Posts: 92 Thanks: 1 Thanked 2 Times in 1 Post	the size of our tire footprint is almost all decided by the first number. 185/70/R15 tire will be 185 mm wide. 185/85/r15 tire will also be 185 mm wide. the '85 will be a little taller but the footprint will be the same size. 185's are the narrowest you will find in a tire store today. I have managed to find 125's from a supplier that sells to people who are restoring vintage vehicles and many really old ones had narrow tires that you don't see today. the thickness of the tread is 2.75" wide instead of almost double that on my 195/70/R15's. Last edited by mans; 12-26-2011 at 02:21 PM..