According to BCI chief executive officer Phillip Oldridge, considering recent changes to the Falcon 45 coach, the choice of the Navistar engine choice was a simple one.

“First of all we preferred the alternative to using urea,” he says. “But the engine choice also considers our recent changes to the engine compartment, cooling system and engine cradle for the 2010 Falcon 45.”

The Navistar Maxxforce 13 bolts into the engine cradle, which slides into the back of the bus on rails as one complete unit, It bolts to the main chassis and attaches to the transmission. Oldridge says it is a very clean and efficient set up for maintenance.

Brian Sullivan of the Navistar Engine Group says because the Maxxforce 13 does not require the extra equipment to handle urea injection, this technology provides the lowest cost of ownership. He adds that coach operators will have the extra convenience of not worrying about what is going on at the tail pipe.

“Our company believes at this point this engine will result in a lower upfront cost,” he says. “We also believe coming to market without the urea liquid solution will translate into higher resale values when comes time to sell the coach.”

Oldridge also expressed concern for operators in colder climates.

“Because urea can freeze at very low temperatures, the holding tank would require a pre-heating system,” he says. “Actually there are a number of areas with the urea solution that we thought might create issues, or at least prove troublesome. We did not want to subject our customers to this if we could find a way around it.”

BCI saw its opportunity through its partnership with Navistar, due in part to the acceptability of the enlarged engine compartment.

Oldridge says he also expects an increase in fuel economy from the 2010 Falcon 45 with the Maxxforce engine connected to the CX Caterpillar transmission.

“It has required some changes in the programming,” he says. “But the CX marries perfectly with the Maxxforce 13.”
He says the changes have resulted in a one-ton reduction in the overall weight of the vehicle.

To satisfy 2010 EPA emissions compliance, Navistar Maxxforce hs gone with Advanced EGR to prevent NOx formation in the cylinders.

This technology featuring a high-pressure common-rail fuel system and dual sequential turbos offers an alternative to the use of urea.

Navistar points to four key technologies that make Advanced EGR an effective solution.

In related developments, BCI director of engineering David Oldridge says the company has been gearing up for its Buy America certification. Later this year the coaches will arrive from the manufacturing plant in China for final assembly and installation of the Navistar Maxxforce 13 at its new facility in Los Angeles, CA.

A key feature of the redesign of the Falcon 45 was to ensure the engine compartment would house the Maxsforce 13 in its cradle. Oldridge says following testing this spring, installation of the new engine will begin 3Q 2010. BR

Now operators have only to focus their attention on how to deal with Diesel Particulate Filters (DPF) in a way that creates the least amount of disruption to safety and to business.

In general the DPF collects soot and ash produced by the engine and converts it to carbon dioxide gas. In this process of regeneration, or re-greening, the DPF heats to a temperature in the conversion and expels the gas out the tailpipe. At some point technicians may need to remove the filter and clean out the residual soot and ash using a special machine to regenerate — or regen for short — the DPF. The cost for this process is approximately $400 plus labor based on the operational profile, the climate and overall conditions during operation.

Here is the rub. A motorcoach operating at low average speed, such as a sightseeing bus or trolley may never achieve the mph required for automatic regeneration. As I have discovered in my fleet of sightseeing buses driving around Chicago, this becomes an inconvenience to the operator when the DPF does not regenerate automatically on public streets. But the DPF still needs periodic regeneration. This is why it is vital that operators of any slower moving vehicle understand the regen process, what triggers the DPF and how to regenerate it when normal operation does not trigger the process automatically.

This is not just a matter of a clogged DPF that pollutes more. Failure to regenerate automatically or manually can become a serious problem if the dash light illuminates and the condition goes uncorrected. The emission control monitor (ECM) will kick in and derate the engine power to where it travels only at very low speeds regardless of throttle position. This should force the operator to regenerate the DPF and not ignore the problem. Left alone this condition eventually renders the bus undriveable, stopped or slowed in a travel lane creating the potential for an accident.

Automatic and stationary regeneration
Automatic regen occurs when the vehicle is under a heavy-duty load cycle or above a predetermined road speed and rpm. In some cases the road speed threshold may only be 20 mph, but moving any slower the engine will not automatically regenerate.

During automatic regen the system takes over and conducts the process, which the operator does not detect with the possible exception of a slightly elevated noise from the turbocharger. This is due to the VGT feature on some engines that elevates exhaust temperatures to complete the process.

In buses and motorcoaches that normally travel at road speeds greater than the threshold of say 20 mph, the regen process occurs automatically without assistance from the operator. However for any vehicles that run at average speeds below this threshold, operators will need to conduct the regen process manually.

In the case of stationary regen, using the Chicago Sightseeing Co. fleet as an example, the average road speed for sightseeing buses is seven mph, according to the ECM. This is too low of a speed to ever trigger the automatic regen process, and calls for stationary or forced regeneration for this group of vehicles.

The stationary process is simple. OEMs have provided a dash switch that activates the regen process while the vehicle is stationary with the transmission in neutral and the parking brake applied. I have found in some cases the OEM has not activated the stationary regen capability within the ECM. In this case the technician will need to attach a laptop computer with the appropriate software and manually to change the stationary option from disable to enable. A simple process, but one that requires the correct equipment and a little know-how.

During the regen process the exhaust temperature can reach as high as 1,500 degrees F — well above the auto-ignition temperature of almost all fluids and other combustibles on the vehicle. Before initiating the process, park the vehicle away from people in a location where the heat will not damage the pavement and the surrounding area is not a fire hazard. Some OEMs have included an additional dash light that will illuminate if the exhaust temperature reaches a critical level. This indicates nothing more than the exhaust temperature and will not derate the engine power or stop the vehicle.

The most practical way to reduce the exhaust temperature is to begin driving. This is as simple as going around the block a few times at a slow rate of speed. This will wash cooler air over the DPF, creating a convective cooling effect and reducing the DPF temperature. In some cases the diagnostic software can initiate and perform the stationary regen process.

A forced duty cycle is a second stationary regen method. This method simply puts the vehicle of slow average speed into a duty cycle that exceeds the threshold required to trigger the regen process.

At Chicago Sightseeing we simply drive the vehicles out on the expressway periodically to force the DPF to regen. Typically, once the DPF light comes on, a 20-minute drive at 55 mph will force the regen process to convert the soot and ash and turn off the dash light. As with the stationary method, in some cases the vehicle will need to travel at a slow rate of speed until the DPF cools down and turns off the dash light.

Operators need to further understand there are different stages of DPF blockage. Some manufacturers cite as many as four stages of blockage. Once the system reaches stage four no amount of attempts, regardless of method, will clean the DPF and the dash light will remain illuminated. The only way to put the vehicle back into service at this point is to remove the DPF and have it cleaned in the appropriate cleaning machine.

For either regen action, the dash lights indicate the DPF needs cleaning. There are typically two dash lights for the DPF system, but the check engine light doubles as an indicator that the DPF system needs a regen.

Even if the DPF system senses the need but the condition is not severe, the DPF dash light will still illuminate.

When it hits severe levels and the system begins to derate the engine, the check engine light will illuminate simultaneously with the DPF light, indicating the DPF needs to regen immediately.

Cummins says DEF will be available before operators take delivery of their first 2010 vehicles with SCR technology.

As 2010 approaches bus and motorcoach operators will read more and more about Selective Catalytic Reduction (SCR) and the fluid that makes it work — diesel exhaust fluid (DEF). Contrary to the popular belief that DEF will be in short supply, Cummins, a manufacturer of diesel engines based in Columbus, IN, says this is not the case.

DEF is essentially a compound of a specific concentration of urea and water. Urea is a prime component in agricultural fertilizers already manufactured in bulk quantities. The U.S. alone produced 12 million tons in 2007, and world production reached 159 million tons. Clearly, supply is not going to be an issue.

Virtually every major diesel engine manufacturer is using SCR as its solution to meet the more stringent emissions standards of 2010. Most diesel automobiles will also use DEF. With that kind of demand operators can be sure everyone will be stocking DEF. Drivers will able to restock at every major truck stop along the highway, as well as at gas stations.

In fact, DEF is already available through Cummins Filtration and Cummins distributors, which includes more than 2,500 retail locations and 20,000 distribution points throughout the U.S. and Canada.

Cummins already stocks DEF through its authorized service network. Today, a full year in advance, more than 15,000 car and truck dealers distribute DEF, and dispensing equipment is being developed and produced for fleet self-fueling.

Dispensing technology and packaging are already in use throughout Europe, where 65 percent of commercial vehicles sold in 2008 were equipped with SCR and used DEF. It is currently available throughout North America in 10-liter jugs, 55-gallon containers and 275-gallon internal bulk containers, with 1,000-gallon bulk filling stations on the way. BR

The MY09 pushbutton control and Allison 3000 combine efficiencies to positively affect the bottom line.

With a reputation for its design and production of fully automatic transmissions for a wide variety of vocational applications, Allison Transmission, Inc., Indianapolis, IN, is dedicated as well to helping its customers operate as efficiently as possible, particularly in a down economy.

For example, test results suggest the company’s fully automatic transmissions in conjunction with the appropriate duty cycle for that particular vehicle can provide superior fuel efficiency and optimum fuel economy.

Allison breaks a vehicle duty cycle into four separate components: acceleration, cruise speeds, deceleration and idle, with acceleration and cruise speeds having the greatest impact on fuel consumption.

According to Lou Gilbert, North American marketing director, the greatest fuel efficiency comes with smooth, seamless full-power shifts from an automatic transmission that transfers uninterrupted engine power to the road. He says manual and automated manual transmissions interrupt engine power with every shift.

“Any interruption in engine power during a shift creates powertrain inefficiencies,” says Gilbert. “It creates a loss of vehicle energy and lower average speeds for the amount of fuel consumed. Drivers will recognize higher average speeds in full-power shifts as opposed to manual or automated manual transmissions.”

The U.S. Environmental Protection Agency (EPA) SmartWay program will soon include a test protocol proposal to measure the fuel efficiency of medium- and heavy-duty commercial vehicles for the first time. According to industry reports, the EPA fuel consumption metric for this test will be fuel consumed per amount of work performed, which is not the same as simply miles-per-gallon (MPG).

Allison Transmission says it commissioned Transportation Research Center (TRC), East Liberty, OH, an independent, third party test facility to conduct fuel consumption testing. The recently completed research provided TRC with two medium-duty trucks of equal specs — one equipped with an Allison 2200 HS; the other with a comparable automated manual.

Allison says at cruising speed the recommended engine RPM is the most critical component to maximum fuel economy.

“If a vehicle used in town runs 60 percent of the time at 40 mph, it does not make sense to spec that vehicle to cruise at 65 mph, which happens to be the engine manufacturer recommended RPM rating,” says Gilbert. “Fleet managers know how their vehicles are used and should write their specs according to that duty cycle.”

TRC test results show that the Allison-equipped vehicle produced significantly lower engine RPM versus the automated manual-equipped truck at many cruise speeds below 40 mph, which resulted in less fuel used. At higher cruise speed ranges, the two transmissions produced comparable engine RPMs and fuel usage.

Allison offers a choice of operating modes to best suit the driving conditions and duty-cycle needs of end-users.

The magic of the shift mode button
The company says its primary and secondary shift mode button located on the shift selector for the Allison Highway Series enhance fuel savings or add more power. In economy mode, the transmission shifts at lower engine speed to improve fuel economy by as much as 5 percent. In performance mode, the transmission upshifts at higher engine speed to provide quick, smooth acceleration.

Switching oil significantly extends drain intervals
The recent addition of new advanced prognostics capability to its entire range of Allison automatic transmissions provides operators with an electronic fluid and filter change indicator that monitors the specific operating conditions for each bus.
Allison says a 6,000-hour drain interval for city transit buses is possible with synthetic oil, and operators using mineral oils should consider a switch.  In the UK, Plymouth City Bus proactively investigated the use of synthetic oils to improve operating efficiency in its fleet of more than 170 buses. The agency reports lower costs and reduced environmental waste after increasing drain intervals by more than three times.

Allison says conventional petroleum-based transmission fluids can oxidize quickly and undermine the effectiveness of the additives, viscosity enhancers and detergents. Allison recently announced its new fully synthetic fluid specification TES295. Working with Castrol, Allison developed TranSynd oil, but states that any TES295 fluid can deliver the same maintenance, environmental and operating benefits.

Allison recommends fluid analysis as the primary method for determining fluid change intervals, which assesses oxidation, contaminant levels and viscosity. The company notes that glycol and water are probably the most common and harmful contaminants found in a transmission. Water is a poor lubricant and can cause corrosion. Glycol can attack the bonding material used to join the clutch friction material to the steel plates. BR