By Paul Abelson
For decades, car makers have engineered to meet the National Highway Traffic Safety Administration's (NHTSA) Corporate Average Fuel Economy (CAFÉ) standards. Now at 27.5 mpg, the requirement will increase to 35.5 mpg for the 2016 model year. If that seems draconian, just wait: Some experts speculate that proposals of 47 mpg to 62 mpg are coming for 2025.
Obviously, these requirements don't pertain to work trucks; they're for Class 1 passenger cars and light-duty vehicles. But commercial vehicles from Class 2 (250/2500 series) pickup trucks to Class 8 dump trucks and plows are under scrutiny, too. Though they comprise 4% of the on- and off-road universes, they consume roughly 20% of their fuel.
Recognizing that, the U.S. EPA and National Highway Traffic Safety Administration (NHTSA) are preparing new fuel economy and emissions standards for vehicles that do more than move people.
The agencies chose model year 2010 as the base for measuring improvement because it represents the final phase of required diesel emissions reductions, a goal that's taken more than a decade to reach.
In 1998, engine manufacturers were given six years to engineer the first reductions. For model year 2004, nitrogen oxides (NOx) were reduced to 2.4 grams per horsepower hour (g/ hp-hr). But because the Clinton Administration accused manufacturers of cheating to improve fuel economy, the EPA's 2004 deadline was moved up to October 2002.
In 2007, particulates (soot, unburned fuel, lube oil evaporations, and ash) were to 1.2 g/limited to 0.01 g/hp-hr, and NOx was dropped hp-hr. For EPA 2010, NOx to a barely measurable 0.02 g/hp-hr.
The new proposal cuts carbon dioxide and greenhouse gas emissions by 20% beginning with the 2014 model year. By 2018, average fuel consumption will be reduced by 20%.
However, reductions will no longer be measured in grams per horsepower hour. Instead, because we're talking about work vehicles, not passenger cars, payload also will be considered. The new metrics will be:
- grams of CO2 per ton-mile, and
- gallons of fuel per 1,000 ton-miles.
Concentrating only on exhaust restricts innovation. With emissions about as low as they can get, focusing on ton-mile metrics opens up opportunities for new research.
Manufacturers can tweak engines to get a few more tenths of a mile per gallon, but now they also can consider weight savings, aerodynamics, tire technology, and additional technologies as yet undreamed of. Meeting environmental goals has had a price, but now there's a payback. Some will come in fuel savings; the rest from increased payloads.
The amount of CO2 an engine releases is directly proportional to the type and amount of fuel it burns. That proportion is fixed. But the more efficient the vehicle, the less fuel it needs. If the same amount of work can be done with fewer trucks, less fuel is consumed and emissions are lowered.
Payload can be increased by developing a lighter-weight vehicle. If new materials — high-strength alloy frames, foamed metal axle housings, and composite cross members — shave 1,500 to 2,000 pounds off vehicle weight, you can haul that much more dirt, salt, or water.
For example, a 20,000-lb. dump truck loaded with 20,000 lbs. of rock has a gross vehicle weight of 40,000 lbs. If the manufacturer shaves 1,000 lbs. from the vehicle's weight, the truck can carry 21,000 lbs. of rock – a 5% pay-load increase. In the end, this means fewer trips to carry the same amount of material.
Many technologies will take time. Some are in their infancy but, stimulated by regulation, could enter production in time for model year 2018. That extra ton or so would decrease emissions and increase ton-mile payload measurements up to 10% — which is half way to the proposed goal.
Unlike emissions standards, which are tied to power generation regardless of vocation, EPA and NHTSA recognize application differences between classes and uses. Accordingly, they've developed 10 regulatory classes separate and distinct from DOT weight classes (see sidebar at left).
Details are scheduled to be released later this summer, but EPA envisions greenhouse gas ton-mile reductions in 2014 to be realized through the application of existing technologies. For 2018, the agency sees the requirements as “technology-forcing.” In other words, engineering lighter-weight materials, waste heat recovery, and new fuels — to name a few developing technologies — will enable manufacturers to meet the goals.
We may soon see systems that capture waste exhaust heat to drive turbines, harness turbine-electric power to augment hybrid propulsion, and new fuels like diesel derived from algae.
Ever skeptical of big government, I approached these changes as another idealistic program that would wind up saddling customers with high costs and little benefit.
But while researching the details, I changed my mind. Including ton-miles in payload calculations alters the balance in your favor.
Now I'm a proponent.
— Paul Abelson (firstname.lastname@example.org) is a former director of the Technology and Maintenance Council (TMC) of the American Trucking Associations, a board member of Truck Writers of North America, and active in the Society of Automotive Engineers.
To read more about new emissions standards, click here.
|THE BIGGER PICTURE
New classifications include vocation in a vehicle's overall emissions profile.
The U.S. EPA and National Highway Traffic Safety Administration have developed 10 regulatory classes as part of the federal government's proposal to cut carbon dioxide and greenhouse gases 20% by 2014. The classifications take power generation and end use into account.
The first seven classes primarily apply to freight delivery and over-the road trucking. The last three are vocational, including plows, dumps, utility, and service vehicles. Equipment transporters (trailers) fall into Classes 5 or 8.
Class 1: Class 8 (more than 33,000 lbs.) combination (tractor-trailer) with high-roof sleeper cab