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Hybrid FedEx, UPS, USPS Delivery Vehicles - Delivering Better Fuel Economy

Rex Roywriter

While the Toyota Prius and Honda Insight are darlings of the environmental movement, perhaps greenies should show a little love to some common looking delivery trucks.

Driven by simple economics and political correctness, businesses like FedEx, UPS, and the United States Postal Service (USPS) are developing fuel-saving technologies to deliver packages to your doorstep. The tech helps trim operational costs while providing opportunities for positive marketing spin.

Simple math helps explain why these companies are experimenting with new technology. Looking at the numbers; Saving 10-percent on fuel for a vehicle that gets only 8 mpg over a yearly driving cycle of 40,000 miles is almost eight times more valuable than increasing the fuel economy of a vehicle getting 30 mpg that is driven only 20,000 miles per year.

This economic reality explains the interest in several non-traditional powertrains being used by three competing package delivery services.

FedEx Delivers Using Less
Currently, FedEx is running a fleet of 264 hybrid delivery vans, the largest such fleet in the country. Their vans aren't shiny new aerodynamic hovercrafts powered by a Mr. Fusion. They are well used 2000 and 2001 conventional Freightliner Custom Chassis Corporation vans with 300,000 to 500,000 miles on the odometer.

The worn out diesel engines in these bread boxes were swapped out for brand new 6.7-liter Cummins ISB diesels. Producing 200 horsepower and approximately 520 lb.ft. of torque, these six-cylinder diesel engines are coupled to an Eaton hybrid-electric motor/generator transmission that is a clever piece of engineering. A 44 kW (peak) electric motor is sandwiched between the engine and the computer-controlled, automated 6-speed manual transmission. The motor receives is power from a 340-volt DC battery pack, and has enough power to launch the truck from a stop and assist with acceleration. At higher speeds, the diesel engine takes over, but all of this is transparent to the driver, who just gets in, keys the ignition, and goes.

Eaton's hybrid controller selects the most efficient mode of operation-diesel, electric, or a blend-depending upon current operating conditions, the battery pack's state of charge, and driver demand. The high-torque characteristics of the diesel engine and electric motor suit the heavy loads of Class 4 Freightliner perfectly, and deliver acceleration that is on-par with standard diesel units.

The retrofit hybrid trucks are projected to improve fuel economy by 44 percent, decrease particulate matter by 96 percent and reduce smog-causing (NOx) emissions by 75 percent compared to the standard FedEx Express delivery truck.

An added benefit of the conversion program is that it extends the life of the vehicles, helping to eliminate waste production and creating a reduce-and-reuse program.

The FedEx hybrid-electric fleet has logged more than four million miles of revenue service since first being introduced in 2004. In total, the retrofitted vans have reduced fuel use by 150,000 gallons. Carbon dioxide emissions have fallen by 1,521 metric tons, which is equivalent to removing 279 cars from the road annually.

The newest 92 retrofitted hybrid vans that hit the road earlier this year are in service in California, primarily in the Los Angeles, San Diego and San Francisco metropolitan areas. The retrofit hybrids display the FedEx EarthSmart logo. FedEx has announced that it is considering similar technology for its larger Class 6 vans.

UPS Hydraulic Hybrid
The FedEx diesel hybrid seems surprisingly normal when contrasted with the Hydraulic Hybrid Vehicles (HHV) now being tested by UPS. The Brown fleet includes some 2,000 low-carbon delivery vans that are powered by everything from natural gas to batteries. Soon, a total of seven of envelope-pushing HHVs will hit the streets around Minneapolis for an evaluation trial.

The powertrain components in the hydraulic hybrid were developed in conjunction (again) with Eaton, and include; a Navistar diesel V-8 engine, front and rear hydraulic pumps, plus high- and low-pressure hydraulic storage tanks. You'll note that missing items include a transmission and driveshaft.

The Navistar VT365 diesel engine, rated at 200 horsepower, is directly connected to the hydraulic pump, not a transmission. Computer controlled pumps and pressure control valves take hydraulic pressure stored in the on-board tanks (the tanks are like batteries in an electric hybrid vehicle) to power the rear axle. A pump at the rear axle recaptures energy during braking, converting the rotational energy into hydraulic pressure. There is no driveshaft linking the engine to the driven axle, so all of the diesel's power goes in to producing hydraulic pressure.

In congested, low-speed urban driving, hydraulics efficiently recapture the vehicle's braking energy. Eaton developed the system and claims that it is about 70-percent efficient at recapturing braking energy if measured on a round-trip basis. Since urban delivery vans stop a lot and often have limited high-speed runs, an efficient means of recapturing kinetic energy is critical to improving fuel efficiency. Of course, conventional vans don't recapture any energy during braking, so these gains are important.

UPS's HHV are still in the experimental stage, and are actually a product of a cooperative effort between the U.S. Environmental Protection Agency, Eaton Corporation, the U.S. Army, and Navistar International Corp. Before this current test, the team conducted an 18-month evaluation of a prototype's performance and emissions on a UPS delivery route in the Detroit, Michigan area. Results showed that the patented hydraulic hybrid diesel technology achieved a 45- to 50-percent improvement in fuel economy and a 30 percent reduction in CO2 emissions compared with traditional diesel-powered vehicles.

Results from this earlier test demonstrated that fuel economy was increased compared to a conventionally-powered diesel delivery van in three ways:

  • Vehicle braking energy is recovered that normally is wasted
  • The engine is operated more efficiently
  • The engine can be shut off when stopped or decelerating.

While in Minnesota, the small fleet of HHV's will be monitored for fuel savings and durability. If successful, the EPA estimates that when manufactured in volume, the added costs of the hybrid components should be recouped in less than three years through lower fuel and brake maintenance costs.

United States Postal Service - Conquering rain, heat, and gloom...
The United States Postal Service operates the largest civilian vehicle fleet in the world, with approximately 220,000 units. Over 142,000 of these are the ubiquitous rolling bricks called the Grumman Long-Life Vehicle (LLV). Standard LLVs were built atop a Chevrolet S-10 pickup chassis. The LLVs were produced from 1986-1995, and 99-percent of the originally ordered trucks are still making their appointed rounds.

The USPS knows how to do some things on a budget.

A one-cent increase in the cost of fuel translates into millions in additional operational costs according to Wayne Corey, Manager Vehicle Operations. Corey said, "To help save on fuel costs, we are using many different technologies all over the country. There are some special issues for us, including issues of standardization that we're leading the private sector with." He then gave the example of the USPS as the leader behind an SAE standard on a plug in hybrid's electrical connector.

While the US postal system is currently testing a myriad of green options, Corey said, "Do we really need hybrids? Most of our routes are under 17 miles, and this is well within reach of many battery electric vehicles."

Even so, the USPS is testing two fourth-generation Chevrolet Equinox hydrogen-powered, emissions-free fuel cell crossovers. So far, the crossovers are working well, but these are not yet ready for prime time. Corey sees them being useful for longer mail routes.

To service shorter routes, the USPS has several different battery electric vehicles in its fleet, including the T3 Series electric vehicle. It will run up to 25 mph and it has field-swappable batteries, so it can make multiple rounds per day without needing to be stationary for charging. The unit has a range of 40 miles on one set of batteries. It is currently deployed in cities across Florida, California, and Arizona. Given it's configuration, it wouldn't work so well in Maine in February.

Larger loads of mail are carried by a new test fleet of hybrid electric vans produced by Azure. It's a two-ton step van that uses a hybrid electric drive train fitted to a Ford E-450 chassis covered by a Morgan Olson body. The Post Master General is looking for savings of 40-percent on fuel and another 30-percent on maintenance.

To help keep the price of stamps down, we'll take the savings any way they come.