The link states the EPA was concerned IMO about Ford and Honda sandbagging them. They did not want Ford and Honda to show up with tests using 5W-20 oils, get "better" results and then not use 5W-20 in production vehicles. By mandating the mfg. have ample supplies to carry on this improvement in the real world, by requiring factory fill, filler cap markings, dealer and aftermarket oil AT NEARLY THE SAME COST,etc. the EPA was backing up the test results by forcing real world use.
Thats all.........