Buying Advice New Products for 2012 ???

[Grandad4]

What Kohler new designs do, if true, is they accomplish ALL the tier 4 requirements WITHOUT the filtering mechanism that everyone else is using.

That's what they say. And, you're right that would be a definite competitive advantage. It sounds like it's mostly good engineering and tuning:

Kohler Offering Diesel Engine for Tier 4 Compliance

Not sure how much of a real advantage that provides Kohler. The competition can do "good engineering and tuning" also. We also don't know how it will work in the real world yet.

Guess we can all stay tuned and see what happens.

 

[BungeeII]

Kohler explained that its engines achieve Tier 4 Final emission compliance without a diesel particulate filter (DPF) thanks to its direct injection system, cooled exhaust gas recirculation and diesel oxygenated catalyst. 適ohler has applied some tried-and-true technologies from the on-road diesel marketplace, according to Fotsch.
It said the design involves a high-pressure common rail system that uses pressures at 2,000 bar (29,000 PSI), leading to better fuel atomization, better fuel consumption, and fewer emission particulates. Working with the fuel mapping program and other systems, the common rail system gets credit for improving exhaust emissions to Tier 4 Final compliance.

EGR is still in place.
The common rail fuel system is probably Delphi, but that's just a guess.