“Biodiesel and straight rubber don’t mix,” says Postema. As a result, a couple of the off-brand engines in the fleet suffered injector issues after a couple of years. “Some of the rubber seals inside disintegrated. We had to rebuild the injector.” But these were isolated cases. “We know it doesn’t affect all of our injectors because we have trucks and equipment that we have run over a decade [on B99].” In fact, other than these isolated fuel system issues, the company has not had any engine-related problems.
In lower concentrations, biodiesel can actually be beneficial to fuel injection systems due to the dry nature of ultra-low-sulfur diesel fuels. “I would not run anything less than a B5 given ultra-low-sulfur fuels nowadays,” Postema states, “because your lubricity really jumps up.”
As a precaution, Postema recommends that contractors who switch to biodiesel keep extra filters on hand. “It definitely cleans the gunk out of a system. Just have some filters on hand and when it starts missing, change that filter out,” he advises. One of the machines in the Earthwise fleet went through a couple of filters after the initial switch, and now runs better than it did before.
“Running B20, I don’t expect you to have any problems unless you have a real dirty fuel system,” Postema states.
A more conventional approach
Iowa-based Manatt’s Inc. is a road construction, ready-mix concrete and concrete and asphalt paving contractor. Over 600 people are employed under the Manatt name. The company has 300+ heavy trucks. Other equipment includes pavers. trimmers, motor graders, loaders, dozers, scrapers, excavators, crushing equipment and milling machines.
The company has been using biodiesel for approximately 10 years. “We run anywhere from 2% to 20%,” says Curt Manatt, vice president. “We typically drop back to 5% in the winter months. Based on what we hear about lubricity, we never go below 2%. We think we need a minimum of 2% to add some lubricity to the fuel.”
This summer, the company plans to use B20. “By going with B20, we are saving $.04 a gallon at this point in time,” says Manatt. “It all adds up. When you buy it by the transport load, it is all money worth saving. As long as it is equal or less, we will burn 20%. If we start paying too much of a premium, we will cut back a little.” It is important to note that most manufacturers’ warranties will allow the use of up to B20 fuel.
“We feel like it has been a good fuel,” says Manatt. “It is a cost savings and it is good for the environment and good for the economy with benefits to the farmers. Biodiesel has become more plentiful and it is more acceptable. Here in Des Moines, we buy ours from Diamond Oil.”
Manatt suggests looking at the economics. “Sometimes the price is up and sometimes it is down based on supply,” he comments. “Recently, it seems like the biodiesel is a better price. That is what determines our percentage. As long as it makes economic sense, we burn it all the time. Whatever the price, we always burn at least 2%.
Manatt has also been investigating future use of compressed natural gas (CNG). At CONEXPO-CON/AGG, he was interested in a CNG-powered ready-mix truck on display by McNeilus. “They brought the truck down to show us last summer. The interesting thing was they had to haul it down on a lowboy because they couldn’t get here and back,” he notes.
“At this point, it is an issue with fueling stations for us,” he continues. “We would be doing that right now if we had the fueling figured out.” The first public CNG station has just opened in Iowa, so availability is still a major factor.
In addition, previous CNG trucks were a little down on horsepower. “That is supposed to be taken care of pretty soon. That will be changing things around a little as it becomes more popular,” Manatt says. “It is just a matter of time before it hits the market. These are pretty exciting times.”
In the meantime, Manatt is investigating dual-fuel options that help to would address the interim while the CNG infrastructure is being built. “If you run out of natural gas, it runs on straight diesel,” he points out.
Make your own
Alabama-based McInnis Construction is a family owned general construction business that has been building bridges, grading roads and building pads, driving piles, pouring concrete and constructing buildings for over 40 years. It has completed projects in Alabama, Mississippi, Louisiana, Florida and Georgia.