You will gain approx 10% more power, as diff ratios have an approx 10% step
between ratios offered (generally)
10% more power will be a hot discussion...leading to arguments...but here is
the laws of physics...
Since lower (higher numeric) change of approx 10% and the tranny/etc are the
same as before (same gear, etc)...the ICE will be spinning approx 10% more
at the same speed.
Since it is spinning 10% more, it will be in a higher portion of it's torque/HP
curve. Therefore more power...as long as the ICE has enough left on it's
torque/HP curve to go higher without hitting rev limits
Not just the additional weight, but the biggie will be the frontal area. Some
times it can become the main factor on performance