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Maintenance Management: Tier 3 off road

June 12, 2007 |

Between January 1, 2006, and January 1, 2007, a new generation of low-emission Tier 3 diesel engines will begin rolling off assembly lines. There won’t be any surprises as far as the technology and performance of these engines – most of the technology was decided on in 2002. Caterpillar is forging ahead with its ACERT (Advanced Combustion Emissions Reduction Technology) and the rest of the OEMs are producing Exhaust Gas Recirculation (EGR) designs or manipulating fuel injection for more complete combustion.

With low-sulfur fuel coming down the pikes, these technologies will meet the U.S. Environmental Protection Agency’s emissions requirements for off-road engines without modifications or after-treatment devices until Tier 4 comes due in 2011.

Yet even though the engines’ designs are established, a lot of related technology is changing between now and the advent of Tier 4. For example:

Some regions of the country are setting their own emissions standards, which will require the installation of aftermarket devices on heavy equipment with pre-Tier 3 engines.
New heavy-duty diesel lube oil standards are being finalized for adoption in late 2006.
The sulfur content of off-road diesel fuel is going to drop from the current level of around 3,000 parts per million to 500 ppm in 2007 and then 15 ppm in 2011.

After treatment or else
In the past, engine exhaust standards were set as a national standard. Only Southern California (because of its notorious smog), was granted the right to enforce stricter rules than the EPA national standards. But this principle has flown out the window in the past few years and there are now multiple regional jurisdictions that have imposed their own emissions standards in excess of what EPA requires. And it’s not just California. Contractors wanting to bid on any number of government-funded projects throughout the country are being asked to meet stricter emission standards well ahead of the national timeline.

The only way contractors can meet these standards with their current machines is to install aftermarket exhaust after-treatment technology. These devices are readily available, but they’re not cheap, running anywhere from $3,000 to $30,000. And because they’re fairly large components, they’re most often installed outside the machine’s engine cowling or hood. Once you have them installed though, these devices can bring a Tier 0, 1 or 2 engine up to essentially the same particulate matter emissions standards as a Tier 3 engine – so you can still bid on publicly funded jobs in these areas and not have to repower or replace an older machine.

There are two types of exhaust after treatment: