Performance And Cost Of Other Types Of Light-Duty Vehicles

Most of the results of OTA’s analyses of mid-size autos apply similarly, on a percentage basis, to other auto size classes—such as subcompacts—and to light trucks. There are, however, some interesting differences. For example, the aerodynamics of different vehicle classes are subject to different constraints. Subcompacts are unlikely to attain as low a drag coefficient as mid-size vehicles because their short lengths inhibit optimum shapes for minimum drag. Pickup trucks, with their open rectangular bed and higher ride height have relatively poor drag coefficients, and fourwheel-drive pickups are even worse, because of their large tires and higher ground clearance. And compact vans and utility vehicles have short noses, relatively high ground clearance, and box-type designs that restrict drag coefficients to relatively high values. Although each vehicle type can be made more aerodynamic, it is unlikely that light-truck drag values will decline quite so much as automobile drag values can.

Another important difference is market-based—historically, introduction of new technologies on light-duty trucks has typically lagged by five to seven years behind their introduction in cars. Although this lag time might change, it is likely that some lag will continue to persist.

Differences in the functions of the different vehicle classes will affect fuel economy potential, as well. For example, the load-carrying function of many light trucks demands high torque at low speed, and may demand trailer-towing capability. The latter requirement, in particular, will constrain the type of performance tradeoffs that might be very attractive for passenger cars using electric or hybrid-electric powertrains.

Whereas OTA expects the business-as-usual fleet of automobiles to improve in fuel economy by about 24 percent between 1995 and 2015, the fuel economy of the light truck fleet is expected to increase a bit less than 20 percent. Prices will scale with size: for example, for hybrids, subcompact prices will increase by about 80 percent of the mid-size car’s price increment, compact vans by about 110 percent, and standard pickups by about 140 percent, reflecting the different power requirements of the various vehicle classes.

Lifecycle Cost---Will They Offset Higher Purchase Prices?

Although vehicle purchasers may tend to focus on initial purchase price more than on operating and maintenance (O&M) costs and expected vehicle longevity in their purchase decisions, large reductions in O&M costs and longer lifespans may offset purchase price advantages in vehicle purchase decisions. For example, diesel-powered vehicles typically cost more than the same model with a gasoline engine, and often are less powerful, but are purchased by shoppers who respect their reputation for longevity, low maintenance, and better fuel economy, or who are swayed by diesel fuel’s price advantage (in most European nations), or both. Proponents of advanced vehicle technologies, especially EVs and fuel cell EVs, often cite their claimed sharp advantages in fuel costs, powertrain longevity, and maintenance costs as sufficient economic reasons to purchase them—aside from their societal advantages.5

A few simple calculations show how a substantially higher vehicle purchase price may indeed be offset by lower O&M costs or longer vehicle lifetime. Assuming a 10 percent interest rate and 10-year vehicle lifetime, for example, a $1,000 increase in purchase price would be offset by a $169 per year reduction in O&M costs. Since average annual maintenance costs for gasoline vehicles are $100 for scheduled maintenance and $400 for unscheduled maintenance over the first 10 years of vehicle life,55 there is potentially a substantial purchase price offset if advanced vehicles can achieve very low maintenance costs. Similarly, an increase in vehicle price of about 25 percent—for example, from $20,000 to $25,000-would be offset by an increase in longevity of 5 years, assuming the less expensive vehicle would last 10 years.

OTA’s evaluation of lifecycle costs leads to the conclusion that their influence will offset sharply higher purchase prices only under limited conditions. For example, unless gasoline prices increase substantially over time, any energy savings associated with lower fuel use or a shift to electricity will provide only a moderate offset against high purchase price-primarily because annual fuel costs are not high in efficient conventional vehicles. In the mid-size vehicles OTA examined for 2015, for $1.50 a gallon gasoline, the minimum savings (NiMH EV versus baseline vehicle, savings of about $400 per year—see table 1-3) would offset about $2,300 in higher purchase price for the NiMH EV. In contrast, the EV may cost as much as $10,000 more than the baseline vehicle. Moreover, percent of the fuel cost savings could be obtained by purchasing the mpg advanced conventional vehicle, which costs only $1,500 more than the baseline vehicle.

Experts contacted by OTA generally agree that electric drivetrains should experience lower maintenance costs and last longer than ICE drivetrains. The amount of savings is difficult to gauge, however, and may not be large because of continuing improvements in ICE drivetrains (for example, the introduction of engines that do not require a tune-up for 100,000 miles) and the likelihood that future electric drivetrains will undergo profound changes from today’s, with unknown consequences for their longevity and maintenance requirements. Moreover, battery replacement costs for EVs (and hybrids and fuel cell EVs to a lesser extent) could offset other savings, 59 although this, too, is uncertain because it is not yet clear whether battery development will succeed in extending battery lifetime to the life of the vehicle. Vehicles with hybrid drivetrains may experience no O&M savings because of their complexity. Finally, although analysts have claimed that fuel cell vehicles will be low maintenance and long-lived, 60 the very early development state of PEM cells demands caution in such assessments, and we see little basis for them. In particular, fuel cells have a complex balance of plant,61 a methanol reformer with required gas clean-up to avoid poisoning the fuel cell’s catalysts, and a number of still-unresolved O&M-related issues such as cathode oxidation and deterioration of membranes.