1: Moly faced piston rings 2: Oil technology 3: Fuel management

4: AND this is probably the most important one, more so than the rings, harder bore sleeves. In 1981 it became federal law that cars had to pass emissions for 5 years/50000 miles. Old engines that were shot at 100K miles had significant bore wear at 50000 miles too (and were sometimes in need of a rebuild then). Bore wear leads to oil consumption and other nasty things that show up in emissions testing. So manufacturers had to make the bores hard enough to not be significantly worn at 50000 miles. A bore that is hard enough to not wear .001 at 50K miles doesn't wear much more at 100K miles, or 150K, and so fourth. Thats why we have engines with 300K miles that don't burn any oil and still make great cranking compression.