Three approaches to efficiency…but are they fun to drive?

With gasoline prices reaching new levels in the United States and concerns about global warming rising, the past few years have seen a renewed interest in fuel-efficient cars. In the most visible example of this trend, Toyota has been notably successful with the Prius hybrid. So notable, in fact, that Bob Lutz, Vice Chairman of General Motors, has wondered aloud whether GM should have pursued a similarly aggressive approach to brand-building. Like Mr. Lutz, we admire the Prius’ gas mileage, interior layout, and wear-your-eco-friendliness-on-your-sleeve styling. That said, its driving dynamics are nothing to write home about. So we reached for the official Winding Road gauntlet, and threw it down with the question, “Can’t they make an economy car that’s fun to drive?”

As we started looking into this question more deeply, we discovered some interesting choices. Our first discovery was Honda’s Accord Hybrid. With Honda’s Integrated Motor Assist (IMA) battery/electric motor package boosting the output of its gasoline V-6, the Accord pumps out 255 hp and 232 lb-ft of torque. Given the Honda’s 3500-lb curb weight, those numbers put it in a dead heat with the new BMW 330i in power-to-weight and torque-to-weight specs. Yet, the Accord Hybrid manages to get an EPA mileage estimate of 29 mpg city and 37 mpg highway.  Not exactly Prius territory, but 40-percent higher than the EPA numbers for the BMW, which sports a new fuel-efficient design.

Our second discovery of sorts was the new Jetta TDI.  Europeans have long favored diesel powerplants as the logical way to generate fuel efficiency, and we wanted to see what a modern Eurodiesel could do. One thing we saw right away was that  diesels can put down some impressive mileage numbers, with the Jetta rated at 35 mpg city, 42  mpg highway. We also liked the Jetta’s 177 lb-ft of torque coupled with its 3197 lb curb weight.  And, as icing on the cake, the Jetta is available with a Direct Shift Gearbox (DSG) that is VW’s take on the computer-controlled sequential transmission. We’ve tried and enjoyed these systems in Ferraris, Maseratis, and BMWs, but we wondered how such an approach would work on an economy car.

Finally, we had to check out the Mini Cooper. Mini’s approach to economy is straightforward: low weight. At 2557 lbs, the Mini weighs 20-percent less than the Jetta and nearly 1000 lb less than the Accord. With less mass to move around, the Mini can use a conventional gasoline engine and still get respectable mileage. Even with the Continuously Variable Transmission (CVT) we specified (since our other cars can shift for themselves), the Mini gets 26 mpg city and 34 mpg highway. With a manual transmission, these numbers would go up to 28/36.

So, we ended up with three different powerplants: hybrid, gas, and diesel. We also had three different transmissions: automatic, DSG, and CVT. Add to that the fact that these cars are from three different weight categories and from three different countries, and you might expect three really different driving experiences. You’d be right.

After only a few miles, it was clear that the Accord is set up as a luxury sedan. The seats are soft, and the suspension cruises over bumps with disdain. The car is quiet, and not just at stop lights when the hybrid system shuts down the engine. The back seat is generously sized, with ample leg and head room for passengers in the six-foot-and-over range. And, our test car had plenty of comfort features, including a navigation system that does a fair imitation of iDrive (minus some of the complexity).

The big hybrid powerplant supports this luxury orientation. Because the Accord Hybrid has an automatic transmission, the power of the drivetrain can’t be deployed easily for quick throttle adjustments or cut-and-thrust maneuvers in town. But when you put the hammer down, the Accord does accelerate quickly, aided significantly by IMA. Honda provides a gauge on the dashboard to show when the electric motor is assisting the gasoline engine (and when the engine or brakes are recharging the batteries). What you notice is that IMA comes online when you ask for more mid-range thrust (say half-throttle or more). This is ideal for people who want an economy car, but hate the feeling that they’re risking life and limb on freeway entrance ramps as they wait for their tiny economotor to glacially bring the family sedan up to speed. Such thoughts will be far from your mind in the Accord as you rocket onto the highway or easily pass slow-moving vehicles on two lane roads.

The only unusual chink in the armor of drivetrain greatness (beyond the normal limitations of automatic transmissions) is that the hybrid system in the Accord involves some fairly obvious clunks and whirs as the gasoline engine and electric motor interact. The Accord never stumbles or hesitates when this is happening, but in the context of a luxury car, the complex sounds and vibrations interrupt the sense of poise that the rest of the car conveys.

We weren’t as comfortable in the Accord Hybrid on twisty back roads as we were in town or on highways, as you might expect. The soft suspension tuning just makes the car too vague on these sections. Like many front wheel drive cars, the Accord wants to understeer. In addition, the chassis wants to shift laterally when you dive into a corner. Couple these characteristics with slightly sloppy steering, and the car is difficult to place precisely in a corner.

Interestingly, Honda has fitted the Accord with fairly beefy anti-roll bars, yielding relatively flat cornering. For a luxury suspension, this neatly avoids the unpleasantness of body roll when the car is hustled along at anything above a tepid pace. If you add this to the soft springing and damping that Honda specified, you get a car that seems fairly stable. It filters out the harshness of the bumps and ripples in the pavement. This isn’t a WR kind of car, but Honda clearly knows what it is doing.

Stepping out of the Accord Hybrid and into the Mini involves a bit of culture shock, like moving to a different country. In almost every way, the Mini is the opposite of the Accord. Deep within its little soul, the Mini wants to be a sports car. Actually, deep within its soul, the Mini is a sports car. The first thing you notice is the marvelous steering. The Mini combines a moderately light feel and a pretty quick ratio with near perfect linearity on center. You can accomplish most of what you need to on the highway with small, almost subconscious movements, which gives you the sense that the Mini is tightly connected to your thoughts.

Thankfully, the Mini doesn’t stop there. The suspension settings offer a slice-and dice level of turn-in that is so unlike most other four-wheel drive cars, that you start wondering how the Mini engineers did it. When you couple responsive turn-in with a handling balance that feels for all the world like an oversteer bias, you begin to realize that the Mini designers went all-out to create a suspension that wants to turn. What you net this out, you have an amazingly fun car. Driver after driver got out of our test Mini unable to suppress a huge smile.

Some, including Mini themselves, have referred to this as “go-kart like handling.” We understand the concept, but the Mini has far too much happening in the suspension (something go-karts distinctly lack) for this to be accurate.  The Mini suspension is go-kart like in that it is very direct: The steering and the dynamics of the car are quite linear and so the car does what you ask it to do.

The price you pay for all this handling fun comes in the form of ride harshness. You’ll notice this most around town on potholes, patches, and discontinuities. The resulting small impacts are transmitted directly into the car. Of course, you’ll find the same thing on most Porsches or Ferraris. And we don’t hear those drivers complaining about ride quality.

Porsche and Ferrari owners have lots of power on tap to keep the fun quotient in the stratosphere between corners. The Mini doesn’t. Even with the Mini’s low weight, 115 hp and 110 lb-ft of torque only go so far. Still, the big problem is the CVT.

Continuously variable transmissions hold the promise of optimizing the gear ratio that the engine sees and keeping the engine in just the right part of the power band. On the Mini, the transmission creates the sensation of sapping power while making relatively unpleasant sounds (droning away for an eternity at 3200 rpm is not our idea of fun).

You can get around some of the CVT’s limitations by switching to manual shift mode. Just pop the shift lever to the right, and you can move up and down gears with a flick of the lever, just like you would on a sequential manual box. This approach is fairly responsive, and certainly better than many manually shifted automatics. Shifting like this doesn’t make the Mini fast, but it feels much more responsive. An even better approach, of course, is to go for the true manual transmission.

The other limitation of the Mini is the back seat. Depending on the size of the driver, the Mini is either a three- or a four- passenger car. And even with a smallish passenger up front, leg room in back is in short supply.  In contrast, the Mini’s hatchback arrangement means that it can hold quite large packages, assuming you don’t need the back seat. 

All this carping about details really misses the point, though. The Mini offers pure unadulterated driving fun on almost any type of road at a level that few cars can match. At the Mini’s price, and given its excellent fuel mileage, it is a stunning value.

The Volkswagen Jetta is in some ways as different from the Mini and the Accord as they are from each other. The Jetta is about refinement and sophistication. We also think, more than the other two cars, it shows where the green car of the future should go.

The refinement starts inside. The Jetta is a roomy car, especially for its weight. The back seat isn’t as large as the Accord’s but it will work for tall people. The trunk is huge, and with the rear seats folded down, the car will carry all sorts of cargo. There is not a trace of iDrive, MMI, or any other computer excess (the radio has actual physical knobs for bass, treble, and balance!). And the fit and finish put cars twice the price to shame.

When you begin driving the Jetta, you immediately notice that the suspension feels nicely planted on the road. It follows the road’s bumps and undulations so that you know exactly what is going on, but without undue harshness being transmitted to the cabin. As you take sweepers you notice a bit of body roll, but it is well controlled. The steering feels light, quick enough, and linear. It isn’t in the Mini class, but it fits well with the suspension tuning. At typical speeds in town or on the highway, the Jetta is a pleasure. While it doesn’t tempt you to push harder, the amount of feedback from the chassis is confidence inspiring. You start to realize that the Jetta feels a lot like the new BMW 3 Series. Not quite as flat, nor as controlled, but very close, and a cut above most cars on these factors.

Take the Jetta out onto some twisty sections, and you’ll get a surprise. Like the 330i, you don’t expect such a comfortable car to work so well when pushed. The Jetta isn’t as glued down as the 330i or certainly the Mini, but the suspension is so composed that you can have a blast just making the VW dance from corner to corner. Most cars get thrown off by the bumps or swales on our handling loop and so are out of position more often than not as you enter the second or third corner in a series. Not the Jetta. It just hangs in there, with only a minimal sense that the front tires are doing a lot of work.

The other magical component of the Jetta is the drivetrain. The diesel engine provides excellent fuel economy in part by being down on power. What you forget until you drive it is that the turbo diesel in this car is plenty torquey (clearly Dr. Diesel liked torque), and it makes its torque precisely in the 2000- 3000 rpm band where you often find yourself. Make no mistake about it, this isn’t a big, punchy motor. You can’t wind it out to high rpms for increased power. But it does move forward nicely at part throttle, and it sounds happy doing it.

That sense of part throttle responsiveness is enhanced tremendously by the DSG transmission. DSG does three things that together are a cut above any other automatic we’ve tried. First, DSG uses clutches, as in a manual gearbox. This means that when you’re in a gear and you add some throttle, the car responds immediately because there’s no torque converter to spool up. Secondly, DSG uses two clutches so that the engine is always powering the drive wheels. Unlike sequential manual gearboxes in auto mode, where the single clutch must be disengaged as the transmission is shifted, the DSG approach means power is always on. The result is that there is essentially no pause in forward motion when you step on the gas and the computer calls for a downshift. A related benefit is that DSG is smoother shifting than almost any automatic. Finally, the DSG computer has some fancy logic that guesses which gear you’ll need next.  We thought this might cause trouble, but in many cases the car had already preselected the right gear so that the car didn’t have to shift when we asked for power. As an example, when we got off the throttle in fifth gear and braked for a corner, DSG (apparently) looked at our speed, selected third as the next gear, and when we applied the throttle near the apex, we just motored away.

We loved driving the Jetta. But while it does everything well, it is perhaps too demure to really make an impact in the United States. Still, the Jetta TDI is so close to greatness that we can see it as a model for the future economy sports sedan. The DSG gearbox is state of the art, and with a good set of paddle shifters would make any car proud. If VW could drop in a beefier diesel (say 50 percent more power and torque), we think it would still be competitive with the Accord and Mini in fuel mileage, and have superb real world performance.  Add to that tauter suspension settings, and you’d have a post-global-warming BMW 2002. It might have to be an Audi for people to understand it, and VW/Audi would have to get past a major case of corporate nerves to market the car in the United States, but it would be a blast. 

You can’t blame us for hoping. Until that time, you’ll find us out in the Hill Country in the Mini.