Ok so I have been doing some research and my 195/55/15 tire weighs 19 lbs this is with out rims. Ok so I was thinking I found on Tire Rack a 185/60/15 that is 16 lbs and has a slightly narrower footprint. Now that is 12 lbs of unsprung weight lifted off the car. That would help mpg by a 1-2 per gallon I would think. Less mass rotational weight I think right?


Joe

 

First, the lighter weight is a big help on the effort it takes for your engine to rotate the wheels; however, the radius is increased from 11.72 to 11.87" which means your losing some of that torque resistance gain.
Second, we find that 175/60x15 not only reduces the weight but also the radius as well as narrower tread makes for more economy. If you had much snow your 185/60x15's might be better but in Tampa I doubt it..

 

I didnt think about a 175/60/15 that has to be lighter than 16 lbs maybe 15 which would be 4lbs lighter per corner. I wonder if that would fit on the rims

 

You can always opt for tires specifically made for better fuel economy. I had some Goodyear Eagle LS's before. Great for gas mileage, but crap for anything else.

 

I actually looked those Eagles up and they weigh more than my sumo's. You would think that a lower friction tire would actually weigh less than its stock brethren.

Joe

 

The 175/60x15 tires are right at home on 6" rims. Well within manufacterers specs for accepted rim widths. Any time you want to check that go to Tireracks website and check that size, or that specific tire, under 'specs'.

 

You will still get better mileage even with more weight with the low rolling resistant tires.

 

The purpose of high mpg tires is less rolling friction, not weight. Those tires deform much less than hipo tires and therefore roll easier. But if you do a lot of acceleration with them they may not offer much improvement in mpg.