Quote:
Originally Posted by diesaroo
I meant I don't see any logical reason why the standards 'should' be any different.
Obviously gov't agencies like CARB and the EPA are the ones dictating this, as motorists don't have the political power of say large construction contractors, farmers' organizations and oceanic freight companies.
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I think the only reason that the standards were different was due to the population number of polluting vehicles. They simply mattered more, given the very large number of vehicles on the road.
There are emissions standards for off-road engines, and for heavy trucks on road. They are just on different timelines.
Tier 1 was signed in 1998.
Tier 2 and Tier 3 were phased in up to 2008, but didn't cover particulate matter. They did cover NOx and HC.
Tier 4 is being phased in from 2008 through 2015. It requires post-treatment, just like current automotive diesel standards. That is why Ad Blue is available at heavy truck stops.
Tier 4 is being applied to equipment such as bulldozers and stationary engines. It has caused significant engine redesign with the manufacturers, and at least one major manufacturer withdrew entirely from the highway truck market because of it.
I think we all still see old trucks on the road, belching smoke, and don't realize that it is the grandfathered vehicles that are in this situation, not the new ones. The problem is that old heavy trucks and offroad equipment have a long life, and they won't die soon enough.