Better everything. Electronic engine controls, more accurate engineering and design, better casting technology, better machining ability, lower rpm operating ranges. All these are just normal technological evolution. As far as the single biggest factor? Over drive. You can seal it better, make it tighter, oil it better, and be perfect in metering, and there are still only so many trips up and down a bore before it's not longer able to be efficient at it.

Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.