If you want to see cost savings in action, look at the light duty 1997 F250 pickup. Some bean counter figured out that you could get sufficient clamping force on the rim with only SEVEN lugs instead of 8. Cost savings: 4 studs, 4 lug nuts, 1 less hole in 5 wheels, 4 hubs, 4 rotors, etc. I was a Service Writer at a Ford dealer back then, and I had a couple of customers come in VERY irate because they went to buy aftermarket wheels. One DEMANDED that we swap it over to 8-lug axles... We told him it wasn't possible and sent him to see his salesman.