Let's see 15000-13500 = 1500 or 10% of the 15000 So it WILL make a difference, but you may need test equipment to find out how much (you won't notice it)
I do however recommend the upgrade on a "Burned out Bulb" basis.. When my A/C's failed I went from 13,5K to 15K. on the rear one this did NOT increase the power draw (but it is harder to start. fixing soon) the front one I draw 0.8 amps more again way less than 10% difference.
My front is a Coleman. works great Back is Advent Air. not so easy to work on but .. Well that's the hard to start one.. The fan blew up and I put a coleman fan in it so it sucks now instead of blows (makes it easier to clean the condenser).
