Down Sizing

[BEEF]

Just because it is an inch smaller in diameter doesn't automatically mean it will weigh less. If you went from a lightweight aluminum wheel to a steelie, it could very well weigh more.

Making your wheels smaller (overall diameter of the wheel/tire) is the equivalent of increasing your gearing and thus giving you more torque but at the cost of lower top speed and thus making your motor turn a higher RPM for a given speed.

I was thinking of changing the gearing on a pickup truck that I had (for acceleration). I was going to go from 3.55s to 4.10s. I was told to get a feel for what it would be like, I should swap out my wheels from the stock 29.5s to 26 inch racing tires (those are overall diameter). I ended up just swapping the gears and the acceleration and takeoff were awesome... I lost about 3mpg in the process.

If you are using 14" wheels with meatier tires where the overall diameter is the same as the 15s, then disregard all that I have said. you would get weight savings with that only.