Amazing the improvement from common-rail injection, compared to our old mechanical squirters. As I understand, the advantage comes from both a finer spray and tapering the injection so you don't need the pre-chamber to keep the rattling sound tolerable. Disadvantage is it needs a complex 20,000 psi continuous pump (mechanical) and electronic-controlled injectors. But, if enough are sold, maintaining that complexity might not be too expensive. I have seen decent deals on ebay for such parts when browsing.

So many advances have been made in IC engine controls that a 6 cyl seems to be all one needs today for gas or diesel, even in trucks and performance cars, plus you can now see the mountains in the summer from the SoCal beaches. Most of this came from government-funded DOE research, begun way back in the days of Jimmy Carter's presidency when our energy future looked bleak. He willingly took the blame (plus Iran), but in the long run dedicated engineering research paid off in both engine efficiency and drilling technology. Appears a direct counter to those who demand a tiny federal government.