|
Depends on what dimention you want smaller.
The numbers on the tire means as follows:
225: Your tread width in millimeters
75: Profile (how much tire there is above the rim), measured in percent of tread width. In this case, the height of the tire above the rim is 75% of 225 mm.
15: Rim diameter in inches.
What you DON'T want to do is get smaller diameter tires, for example, going from 75 to 70. This will increase acceleration by a small margin, but at the expense of top speed (which probably doesn't matter) as well as hurt fuel economy. Larger diameter tires will simulate your final gear being larger, resulting in lower RPMs, which means better fuel economy.
What will increase FE by decreasing drag would be narrower tires- 205 instead of 225, for example- But the drawback is reduced traction.
If you want better cornering, you could go with larger rims. These will simulate stiffer sidewalls. Not sure what they'll do for FE, though.
|