Yes it takes less pressure in 2.5's due to increase in surface area of piston

Example:

2.0 piston surface area is 3.14sq-in multiplied by 200psi=628.3185 lbs of force

WHOA! Easy there buddy:)
I already knew all the other stuff about ride ht (thanks for the responses) just thought that was a crazy drop in psi from 2.0's to 2.5's

OR

2.5 area is 4.9sq-in multiplied by 128 psi= 628.3185 lbs of force

So less air pressure but applied over bigger area is the same force

Later

Crashed

WHOA BRAIN? WOW I feel stupider now. Thanks for all the replies, I am aware of the ride ht and the fact that its not "air" but thanks for all the replies. I guess I needed to put more emphasis on the fact that I was dropping soooo much preasure going from 2.0's to 2.5's. Just seemed excessive...