[MetroMPG]

It'll accelerate slower in all gears and run quieter in top gear. Throttle response will be muted. It'll feel more laid back.

I didn't actually measure the acceleration change in my car, because I don't really care. But the stock Metro had something like a 14 second 0-60 mph time flat out. Now it's slower.

You're not changing the engine, so its actual torque characteristics won't change.

If you really want to get a sense of what it'll be like, stick some big wheels/tires on the front end and try it out. (Ideally do the calcs and find a wheel/tire combo that's as close as you can get to your proposed F.D. change.)