VW Lupo: Rough road to fuel economy
Great fuel economy can be a pain.
Volkswagen has just begun selling a revolutionary machine in Germany called the 3L (for 3-liter) Lupo, and after a 150-mile run here from Braunschweig, the lasting impressions are a beastly backache from the cheap seats and maddening frustration from the mechanical compromises necessary to achieve the car's remarkable fuel economy.
The 3L refers not to engine size but to the fact that it is designed to use just three liters of fuel per 100 kilometers - about 78 miles per gallon. No production car in the USA gets close. The three-liter formula is a long-standing environmentalists' challenge that VW is first to answer after nine years of work.
Driven normally, the little Lupo turned in 70 miles per gallon, mainly on two-lane roads through stop-and-start villages. That was 3.38 liters of fuel per 100 kilometers. Others on the test drive, trying to better the target, sipped just 2.79 liters per 100 km, equal to about 84 miles per gallon.
VW markets a variety of Lupos, none intended for the USA because of their tiny size and lack of power. The 3L is a niche model, expected to attract just a few thousand buyers a year.
VW has no plans to sell any Lupo in the USA. But lightweight construction and other fuel-efficient features were portrayed as a U.S.-bound technology if fuel economy ever becomes more important than it is now.
The 3L Lupo uses a 1.2-liter, turbocharged, three-cylinder diesel engine linked to an unusual transmission. It is a five-speed manual because those are more efficient than automatics. But there is no clutch, and the gearbox is shifted automatically by the car, not the driver, to make sure it stays in the most fuel-efficient gear.
One way to cut fuel consumption is to eliminate the weight and power drain of accessories. So the 3L Lupo had no air conditioning, no power steering, no anything. You can add such options, but there'd go your three-liter claim.
And the car seemed low-quality for the $3,000 premium price its fuel-sipping hardware commands.
Not only did the seats turn torturous after about 90 minutes, a cup holder came apart in the first 10 miles. The economy-enhancing, easy-rolling tires and lightweight suspension transmitted not just noise but a roar to the passenger compartment on cobblestones, bricks and rough asphalt.
It's unlikely many buyers in the USA would pay a premium for such privations. VW says German owners would more than make up for the higher price because of tax breaks for fuel-efficient cars and because of lower fuel consumption in a land where a gallon's about $4.
Test cars often are early-production models or even pre-preproduction practice jobs, so it's appropriate to forgive some of the Lupo's gaffes.
What's hard to overlook is the transmission. It's the key hardware that makes Lupo go so far on so little fuel. But even a fuel-economy zealot would have trouble being charitable.
To work its magic, the transmission seeks the highest gear ratio that the engine can handle without stalling, resulting in acceleration so sluggish it almost can't claim to be acceleration at all. It'll cruise 80 miles an hour all day. But ask it to change speeds and oh, woe.
Whether shifting up or down, the transmission's automatic mechanism takes a long time to engage the next gear, then does so abruptly. In the interim, the engine slows almost to a stop. It's as if you're riding with a driver's-ed student unable to synchronize gas, clutch and gearshift.
The turbocharged diesel has surprising pep, enough that you'd not suspect it's rated just 61 horsepower, but the gearbox follies mask the power in the name of fuel husbandry.
Also, to squeeze out a bit more economy, the engine unhooks and allows the front driving wheels to coast, or free-wheel, when you let off the gas pedal. Without an engine-braking effect, you sail up alarmingly fast on the car ahead or the inattentive pedestrian.
Final quirk: The engine stops running if the brake pedal is depressed four seconds or more. That saves fuel at long red lights and during gridlock. Lift off the brake pedal and the starter cranks the engine up.
Revivification happens quickly. But the transmission again delays matters. It takes maddening moments before the gearbox is fully engaged and the car will accelerate strongly. You jam the throttle harder. Then the whole shebang hooks up and, screech, the torque-rich diesel engine tries to turn the skinny front tires into smoking shreds of rubber. So now you're doubly embarrassed: You've held up the line of cars like an inattentive jackass, and then you squealed the tires as if you thought your cute little minicar was some sort of hot rod.
You can bypass the most-damnable behavior two ways.
Switch off the "Eco" button on the dashboard. The transmission gives up its obsession with fuel economy and begins to shift like a normal gearbox. That eliminates the engine shutoff at idle. And it gets rid of the risky free-wheeling, too. Still, the transmission takes too long to shift from gear to gear, and you're still stuck with the fall-on-its-face shift personality.
Fortunately, the transmission also has a Tiptronic feature, allowing you to slide the gear lever sideways and shift up or down when you choose. That's best, but the egregious pause between shifts remains.
More-agreeable technology is under the hood. The turbocharged diesel uses what's called direct injection and some other tweaks to produce sufficient horsepower for highway passing, and nice torque for around-town lunges and for people- and cargo-hauling.
VW acknowledges that it developed the 3-liter Lupo mainly to quiet the environmentalists. Such matters are more serious here than in the USA.
As aggravating as the car is, it keeps the promise of good fuel economy. And it simultaneously proves two things: Extraordinary fuel efficiency is possible with current technology; achieving it is neither cheap nor pleasant.
Bravo to VW for putting its development money where the fuel economy zealots' mouths are. But boo to a car with such flawed behavior.
VW Lupo
What is it? Front-wheel-drive minicar marketed as the first mass-production car to use just three liters of fuel per 100 kilometers (equivalent to about 78 miles per gallon). Though not intended for the U.S. market, the car's technology could be adapted to U.S. models if fuel economy becomes more important here.
What's standard? 1.2-liter, three-cylinder, turbocharged diesel engine rated 61 horsepower; five-speed, manual-style gearbox shifted automatically by the car's computer, or manually without a clutch by the driver; computerized engine shut-off at stops longer than four seconds; extensive use of lightweight aluminum and magnesium; dual front-impact air bags and side-impact air bags; anti-lock brakes.
How much? Equivalent to about $17,000. But consumers get back some of that because the car's high fuel efficiency earns an exemption from German car tax worth about $1,200.
Overall: Rough around the edges, but a laudable technical exercise.