I love fuel injection on gasoline vehicles. I think if it were not for smog reduction and EPA requirements, we'd still be driving vehicles using carburetors and inefficient fuel/air mixtures. When fuel injection started appearing on cars, it was accompanied with a large price increase. However, in the long run, I think fuel injection has been great for fuel economy and reliability. Between fuel injection and high energy ignitions, the tune-up mileage for most cars is every 100k mi. instead of every 15k miles. I DO NOT miss the days of changing points, plugs, and doing carburetor adjustments or fixing stuck floats that dumped raw fuel onto the top of a hot engine. I will lead the cheers for electronic fuel injection, electronic ignition, and performance control computers. When you could buy 4 gallons of gas for $1, it was fine to push those big block fuel guzzlers up and down the road, but I thank my lucky stars that all my vehicles get 20+ mpg today.
I don't know if DEF and Tier 4 will lead to improvements in diesels that can be compared to improvements in gasoline engines. If it does, the first generation will seem more costly and will see lots of resistance. I don't think diesels ever showed performance problems like gassers prior to fuel injection/elec. ignitions. However, if these restrictions drive innovations in diesels that compare to gasoline engine improvements, I'm very excited about the future of diesels. The jury is still out in my opinion. . .:confused3: