Does Smaller Equal Efficient?

If so, then I pity Marge the time when fake Homer gave her a night of "efficient" German sex. I'm pondering the small size of many items here and questioning the notion of German efficiency. Cars I understand; the roads are narrow and gas is expensive. But why are appliances small? German washers and dryers have 1/3 the load capacity of American models. Our built in fridge is small and freezerless, so we just turned it off and use it as a spice rack. Luckily, we have U.S.-style loaner appliances courtesy of Uncle Sam. The lawn mower I just purchased is roughly the size of one I owned at age 5 (it blew bubbles). I have been mowing my overgrown lawn for 3 days and I'm still not done...c'est la vive.