Before the Renault Zoe rolls into European showrooms next spring with a promise of affordable electric mobility, the super-mini car cruised to a fuel-economy victory in the English countryside.

The Zoe emerged as top mass-production vehicle Saturday in the Royal Automobile Club's (RAC) Future Car Challenge, achieving the equivalent of 163.3 miles per gallon (69.4 kilometers per liter) in the Brighton-to-London road rally.

Cars Future and Past

Renault, which pulled out of the U.S. market in the 1980s, has recently begun taking orders for the Zoe in Great Britain and Western Europe, ahead of initial deliveries next spring. The folks at Renault were "absolutely delighted" with the Zoe's showing in the 63-mile (101-kilometer) Future Car Challenge, said Jeremy Townsend, spokesman for Renault UK. "We didn't necessarily expect to win, but we were hoping to." The Zoe made it from Brighton to London using just 129 watt-hours of energy per kilometer. (Last year's production-car winner was the Leaf, which completed a different configuration of the journey using about 140 watt-hours per kilometer—equivalent to 150 mpg, or 63.8 km/l.) (Related Quiz: "What You Don't Know About Cars and Fuel")

This was the third running of the Challenge. The RAC, an automotive insurance-and-services provider akin to the American Automobile Association (AAA), says it sponsors the event to "actively promote, demonstrate and challenge new low-energy technology." Explains David Bizley, RAC technical director: "It's an opportunity to test the technology in a real-world environment."

The high-efficiency car run takes place the same weekend as the RAC's better-known event, the 116-year-old Veteran Car Run, touted as the world's longest-running motoring event. This vintage automobile rally runs roughly the same course as the Future Car race, but in the opposite direction, from London to Brighton.

On Saturday, in a November chill under bright skies, Regent Street's shoppers had a chance to peer at both the past and the future of personal transport. Alongside some of the 449 classic cars ready for the Veteran race on Sunday, the 33 energy-efficient automobiles that ran the Future Car Challenge were on display: from one-of-a-kind follies to prototypes to production cars already in showrooms.

The number of entries in the Future Car Challenge was actually down from last year, when 50 cars competed. Race organizers say there were more multiple entries by the major automakers in 2011, and this year's event had a wider variety of cars. Most of the cars were EVs, but there were also hybrids, extended-range/plug-in electrics, diesels, and one hydrogen-fuel-cell-powered Vauxhall (General Motors' brand name in Britain)—an experimental car called the HydroGen4.

Bizley said RAC takes an "agnostic" attitude toward the various technologies. "And we discourage the government from trying to pick winners," he added. "We think the market should sort that out." Ultimately, Bizely thinks that consumers will opt for a mix of alternative-fuel technologies. "You will pick the vehicle that best suits your needs," he says, and for city drivers, where range is less of an issue, that could very well be an EV.

Priced to Jolt Sales

As in the United States, however, sales of EVs in Britain have been decidedly low-voltage. According to the Society of Motor Manufacturers and Traders, sales of all alternative-fuel vehicles in the UK this year, as of October 31, were 24,266, or just 1.4 percent of the market. And only 950 of those cars were pure EVs. Bizley says the car companies have not done a great job of promoting electrics, and RAC surveys of members and the public find that there's "a lack of understanding of their pluses and minuses; that's one reason the uptake has not been huge." The RAC hopes that the Challenge will help increase public appreciation of EVs and other low-energy cars, he adds.

But high cost has been the primary factor dampening demand, in the view of most analysts. The Nissan Leaf sells in Britain for £26,000 ($41,600), once buyers subtract a government grant (either £5,000 ($8,000) or 25 percent of the full selling price, whichever is less). The Vauxhall Ampera (the Chevy Volt's UK brand name) sells for £29,995 ($47,992), after the grant. Those prices are considerably higher than similar-sized gasoline-powered cars.

"The Zoe is the car that will change that," Renault's Townsend said. "The biggest objection (to EVs) has been price, and it is certainly the answer to that." The Zoe's base price, after the grant, is £13,650 ($21,840). However, Renault is also charging buyers a £70 ($112) a month battery-rental fee. Over five years, that adds £4,200 ($6,720) to the total cost of the car—still making the Zoe a less expensive choice for motorists who don't require a larger vehicle. (See related blog post: How to Compare the Cost of Electric and Gas Cars)

Still, many industry observers believe battery costs need to come down significantly before hybrids and EVs become truly competitive. (Related: "Pictures: "Seven Ingredients for Better Electric Car Batteries") "Demand will be there if we provide the right product," said Paul Bostock, engineering manager for hybrid cars at Jaguar Land Rover, who drove one of three experimental Jaguar XJ_e cars in the Challenge. Jaguar, running the race on its home-country turf, won the prize as the most energy-efficient luxury prototype, and also the Technical Panel's Award of Merit. The XJ_e is a plug-in, extended-range hybrid. Jaguar says it consumed just 1.2 liters of gasoline and 11 kWh of energy over the course, the equivalent of 93.3 mpg (39.8 km/l). Bostock says the XJ_e's performance is equal to that of its elder sibling, Jaguar's gasoline-fueled, 5-liter V8.

The Challenge also highlighted super-efficient diesel technology. Three diesel internal-combustion cars participated, and the winner was a BMW 116d EfficientDynamics, which its drivers estimated averaged an impressive 85.8 mpg (36.5 km/l) during the run. Paul Clarke, editor of the UK's Green-Car-Guide.com, and one of the drivers of the BMW, says for high-mileage drivers who spend a lot of time on motorways (the British equivalent of interstates), "diesels are a great green solution." Unlike in the United States, where diesels remain a hard sell, they are popular in the UK. So far this year, diesel sales account for 50.6 percent of the market.

The most efficient prototype was a rather bizarre entry from German wind-energy company Windreich, which refitted a 1950s-era Messerschmitt—a three-wheeled, two-seater—with an electric motor. While the golf-cart-sized Messerschmitt attracted a lot of attention, it was clearly a novelty act.

A more sporty one-of-a-kind was the Vortex GT3 sports car. It's a kit car that usually uses a 3.0-liter, 225-horsepower engine, but owner Russ Sciville rebuilt his with a 30-to-67-kilowatt AC motor that has a range of 120 miles and a top speed of about 70 mph, and goes from zero to 60 mph in a peppy seven seconds. He finished the car just two weeks before the event. Sciville has also rebuilt a Lotus Elise into an EV. Last year, the Elise won the Best Private Entry award, and completed the run using just 109 watt-hours per kilometer, the energy equivalent of 193 mpg (82 km/l).

Of course, builders of custom cars have more options for shaving energy consumption than automakers styling vehicles with a street-legal size and weight for mass production. (Related: "Pictures: Students Design Super-Efficient Cars in Eco-marathon") Still, the Zoe is seeking to squeeze out more miles per kilowatt with the help of technology, including a heat pump system that reduces the significant battery drain of traditional auto air-conditioning. The Zoe also will feature energy-efficient tires codeveloped by Renault and Michelin that are specifically designed for electric cars.

No matter what the design or build of the car, expert driving and slow-and-steady handling also can boost energy-efficient performance. In recognition of some of these tricks of this trade, Bizley says there were changes to the Future Car Challenge course this year.

In the first two years the Future Cars followed the same back roads as the classic autos in the Veteran Car Run, but this year they used a route equal in distance, but requiring some time on motorways and other higher-speed roads. The route into London also used heavily trafficked roads "where you can do 10 mph only if you're lucky," he said. The mix of different roadways made this year's Challenge an even more realistic test, Bizley says. The organizers also set a three-hour cutoff time for the drivers to complete the journey to discourage unreasonably slow driving that would reduce the amount of energy used to levels unattainable by consumers.