The Western Pacific's Zephyrette consisted of a Budd RDC that was powered by twin inline six General Motors diesel engines, which each produced 275 horsepower (205 kW), and equipped with Allison torque converters.
This setup allowed each RDC to cruise at 70 mph (110 km/h) in direct drive and 55 mph (89 km/h) in torque conversion mode during operation.
The foam rubber seats in the RDCs were rated as "comfortable" at speeds up to 83 mph (134 km/h) and the application of disc brakes allowed fully loaded cars to stop from a speed of 85 mph (137 km/h) in 2,330 feet (710 m).
In 6,000 miles (9,700 km) of testing and evaluation, the Western Pacific determined that its RDCs averaged 2.8 miles per US gallon (1.2 km/l), which at contemporary diesel prices yielded fuel costs of barely over 3 cents per mile; this compared favorably to the performance of steam locomotives on similar routes, which accrued costs of approximately 22 cents per mile.

The new Western Pacific RDC service was dubbed the "Zephyrette" due to both its supplemental relationship and (thanks to its stainless steel exteriors) visual resemblance to the California Zephyr.
After replacing the Royal Gorge in the Western Pacific's timetable, the two Zephyrettes inherited its train numbers: 1 and 2.
The inaugural eastbound Zephyrette left Oakland on September 15, 1950, while the first westbound train departed Salt Lake City two days later, on September 17, 1950.
The service operated on a tri-weekly schedule, with eastbound trains departing Oakland at 7:57 pm every Sunday, Wednesday, and Friday, and their westbound counterparts leaving Salt Lake City at 7:30 am on the same days.
Eastbound, the train's running time was 22 hours and 48 minutes, while westbound it was 23 hours and 30 minutes.
In total, the Zephyrette route extended for 924 miles (1,487 km) and included 19 scheduled stops, as well as nearly 100 conditional stops.

The Zephyrettes lacked the luxurious appointments of the California Zephyr, foregoing foodservice entirely and providing only hot and cooled water for refreshments.
Although the RDCs typically ran the route alone, during periods of peak demand the Western Pacific ran them in short trains behind an EMD F3, a water tender, and a baggage car.
In October 1950, the railroad had computed the direct operating costs for the Zephyrette RDCs at 71 cents per train-mile, almost half the cost incurred by its conventional predecessor, the Royal Gorge.
In addition to their relative economic efficiency, the cars also gained a reputation for reliability: one Western Pacific employee even likened one of the RDCs to "a big Buick".
They also provided numerous advantages over conventional consists, especially in terms of their ability to accelerate quickly and maintain high sustained speeds, which allowed for faster service of the route's conditional stops than had previously been possible.
While the Zephyrettes had initially been profitable for the Western Pacific, they did not remain so, with losses of $255,000 in 1959.
Western Pacific ended use of the Southern Pacific Railroad's connecting cross-bay ferry between Oakland and San Francisco in early summer 1958, then discontinued the parallel bus connection later in the same summer.
The train was scheduled to be discontinued on June 1, 1960, but opposition from residents along the line led to an order from the Interstate Commerce Commission to temporarily delay the train's end.
The service was ultimately ended on October 2, 1960.
The Western Pacific's Zephyrette consisted of a Budd RDC that was powered by twin inline six General Motors diesel engines, which each produced 275 horsepower (205 kW), and equipped with Allison torque converters. This setup allowed each RDC to cruise at 70 mph (110 km/h) in direct drive and 55 mph (89 km/h) in torque conversion mode during operation. The foam rubber seats in the RDCs were rated as "comfortable" at speeds up to 83 mph (134 km/h) and the application of disc brakes allowed fully loaded cars to stop from a speed of 85 mph (137 km/h) in 2,330 feet (710 m). In 6,000 miles (9,700 km) of testing and evaluation, the Western Pacific determined that its RDCs averaged 2.8 miles per US gallon (1.2 km/l), which at contemporary diesel prices yielded fuel costs of barely over 3 cents per mile; this compared favorably to the performance of steam locomotives on similar routes, which accrued costs of approximately 22 cents per mile.
The new Western Pacific RDC service was dubbed the "Zephyrette" due to both its supplemental relationship and (thanks to its stainless steel exteriors) visual resemblance to the California Zephyr. After replacing the Royal Gorge in the Western Pacific's timetable, the two Zephyrettes inherited its train numbers: 1 and 2. The inaugural eastbound Zephyrette left Oakland on September 15, 1950, while the first westbound train departed Salt Lake City two days later, on September 17, 1950. The service operated on a tri-weekly schedule, with eastbound trains departing Oakland at 7:57 pm every Sunday, Wednesday, and Friday, and their westbound counterparts leaving Salt Lake City at 7:30 am on the same days. Eastbound, the train's running time was 22 hours and 48 minutes, while westbound it was 23 hours and 30 minutes. In total, the Zephyrette route extended for 924 miles (1,487 km) and included 19 scheduled stops, as well as nearly 100 conditional stops.
The Zephyrettes lacked the luxurious appointments of the California Zephyr, foregoing foodservice entirely and providing only hot and cooled water for refreshments. Although the RDCs typically ran the route alone, during periods of peak demand the Western Pacific ran them in short trains behind an EMD F3, a water tender, and a baggage car. In October 1950, the railroad had computed the direct operating costs for the Zephyrette RDCs at 71 cents per train-mile, almost half the cost incurred by its conventional predecessor, the Royal Gorge. In addition to their relative economic efficiency, the cars also gained a reputation for reliability: one Western Pacific employee even likened one of the RDCs to "a big Buick". They also provided numerous advantages over conventional consists, especially in terms of their ability to accelerate quickly and maintain high sustained speeds, which allowed for faster service of the route's conditional stops than had previously been possible. While the Zephyrettes had initially been profitable for the Western Pacific, they did not remain so, with losses of $255,000 in 1959. Western Pacific ended use of the Southern Pacific Railroad's connecting cross-bay ferry between Oakland and San Francisco in early summer 1958, then discontinued the parallel bus connection later in the same summer. The train was scheduled to be discontinued on June 1, 1960, but opposition from residents along the line led to an order from the Interstate Commerce Commission to temporarily delay the train's end. The service was ultimately ended on October 2, 1960.
Zephyrette (train)