LAS VEGAS — In many ways, Las Vegas was the perfect setting for the first drive of Volvo’s “60 Series” (XC60, V60, S60) vehicles. The weather was nearly 70 degrees (Fahrenheit) warmer than Detroit, which — like much of the mid-section of the country — was in the grips of the “Polar Vortex” that kept temps in the single digits. Visitors wandered about looking for entertainment and big returns on their bets. And underneath all of the glitter, something was missing.

These are the first vehicles to use Volvo’s new Drive-E engine architecture. Eight engine architectures are replaced by a modular family of gasoline and diesel motors that use 25% of the same part numbers and 50% of parts built to the same concept. Only 25% of the parts are different between the gas and diesel engines. When the engine family is fully launched, there will be four gas and four diesel engines:

Currently, only the T6, T5 and D4 engines are in production, and only the gasoline engines are available in the U.S. The company is watching the take rate for diesels at Audi, BMW, Mercedes and even VW to determine whether or not it should bring those engines here.

As the Euro 6 emission standards take hold, less work will be necessary to make them compliant with U.S. regulations. However, there is a significant price differential between the two, and Volvo has plans to satisfy the fuel economy cravings of its North American customers with plug-in hybrid powertrains.

The top all-wheel drive electrified powertrain will combine the T6 engine with front and rear electric motors and a battery pack located under the passenger compartment. It will have a total of about 400 horsepower.

All-wheel drive will have to wait if you want a Drive-E engine under the hood, however. Depending on model, you’ll get your choice of a 3.0- or 3.2-liter inline six-cylinder or 2.5-liter five-cylinder engine if you tick the all-wheel drive box. Rather than tear up the platform to accommodate the new all-wheel drive system, Volvo decided to wait for the launch of its modular SPA platform architecture that will debut later this year under the next-generation XC90. From there it filters down to all of Volvo’s full- and mid-size vehicles.

Nevertheless, the XC60 crossover is new from the A-pillar forward, and substantial changes have taken place to the front of the V60 wagon and S60 sedan. All told, Volvo spent enough money to do a complete vehicle from scratch just to keep these vehicles relevant with the Drive-E powertrains. Relevance, in this context, means combining both acceleration and fuel economy:

On the Road

Upon arrival we were given the keys to one of several identical XC60 crossovers fitted with the T6 engine. A 276-mile drive in the S60 and V60 was planned for the next day, but Volvo couldn’t wait for us to get our first taste of Drive-E power.

Scrolling through the drive mode choices (Drive, Eco+ and Sport) lets you choose how you want the powertrain to respond. Drive is the default setting, and engages the engine’s stop/start functionality. At almost the same instant you come to a complete stop, the system engages and the engine stops. Take your foot off the brake, and the direct-injected motor restarts. Like most such systems, it’s not unobtrusive. There’s a button on the dash to disarm the system, but you lose out on the approximately 5% - 7% fuel savings that comes when it’s on.

Over time, you’d probably get used to it. The Eco+ mode turns off the air conditioning (this can be overridden by turning it on manually), eliminates engine braking, and keeps stop/start enabled. Sport mode, on the other hand, keeps the air on, allows full engine braking, and disables the stop/start function. It also changes throttle mapping for a more aggressive tip-in that increases off-the-line acceleration.

Las Vegas and environs isn’t the most demanding driving arena. Gradients are minimal, traffic often flows like molasses, and curves are fleeting at best. Nevertheless, this testing ground gave the opportunity to see just how the twin-charged T6 engine deals with hard acceleration from a dead stop, in-gear acceleration, and those situations where you are cruising along in a high gear and suddenly need to accelerate. In all these instances, the T6 motor shines.

The supercharger provides instant boost, allowing the XC60 can dig hard from a stop, and it overpowers the front tires such that they momentarily scrabble for grip. When tipping into the throttle for moderate in-gear acceleration, the supercharger hands off to the turbo almost seamlessly. You are never wanting for boost.

Plus, the combination of a twin-charged motor and an eight-speed automatic transmission (with steering wheel-mounted paddle shifters) pretty much guarantees that you’re not lost for acceleration when its needed. All that glitters, however, isn’t gold. No matter how well it accelerates, the soundtrack is one of a four-cylinder engine. Thus, the soundtrack doesn’t fit the movie. This became apparent the next day when we saddled up, grabbing the S60 for the first leg of our drive.

Blonde, Blue-eyed and Boring?

It’s easy to think of the Swedes as blonde, blue-eyed and boring, and categorize their vehicles in the same way. Slip into the S60, and you are met with a clean, crisp set of instruments that change with the drive mode selected.

Ergonomics are very good, as are the sight lines, and the seats feel as though you could roll out of them on the other side of the country no worse for wear. You are surrounded by a strong, safe structure, the interior materials are top drawer, and everything works with a precision that is more friendly than that of the anal-retentive Germans.

Get out of the city and head Northeast past Nellis Air Force Base toward the Valley of Fire, and the S60 eats up the miles. Roll up on a truck dawdling in the right lane, and it takes little effort to pass it… or the truck in front of him… or the two cars in front of that. Pretty soon you are on the other side of the century mark, wondering how you got there.

And therein lies the problem. The hand-off from supercharger to turbo is so seamless and quiet that you don’t really notice it. There’s no induction roar, exhaust bark, supercharger whine or any other indication that you are piling coals on in the engine room. The dominant sound is that of the wind rushing over the A-pillars and door mirrors. If that noise could be silenced you could be forgiven for thinking that you’d transferred into a Lexus, albeit one with solidity and poise of which the Japanese luxury maker could only dream.

It’s all a bit boring, honestly, and not at all indicative of the Scandinavian personality that pours shots of aquavit at dinner, and yells a hearty “Skål!” before downing it. Rather, the S60 feels subdued, the combination of a slick-shifting automatic gearbox and always-on-the-boost large four-cylinder engine making it seem as though it doesn’t have to break a sweat. Thus, the S60 doesn’t feel 5.6-second 0-60 quick.

Oddly, switching into the V60 wagon after lunch brought a different perspective. Despite the fact that there’s no supercharger and the output is down by 60 horsepower and 15-37 lb-ft (depending on whether you have engaged the overboost function or not), the car feels quicker. The turbo spins up quickly, but the slight lag as it builds to full boost lets you know that there is something happening under the hood. You have to judge your overtaking moves more closely, but you feel as though you are getting more from the experience.

The addition of a large, open cargo area doesn’t add much to the noise that makes its way into the cabin, nor does the change in shape affect the way the car glides along the straights and through the few corners we encountered. Set up for mild understeer, the V60, like its S60 brother. It appreciates a wide entrance and late apex, with all of the deceleration and other work taken care of before committing to the turn. The combination of front-drive and electric power steering leave the helm feeling a bit wooden, though the car goes where you point it.

Beyond the everyday concerns of durability, quality, reliability, passenger and cargo room, fuel economy, etc., a sport sedan is about involving the driver and passengers in the experience of driving. Not to the extent, certainly, of a sports car, but much more than you would experience in your average family sedan.

It also should surround you in premium materials and an appropriate level of comfort, convenience and technology. Volvo’s 60 Series Drive-E cars accomplish the last half of that equation, but have trouble with the first half. Despite being showcased in the middle of Sin City, it was possible to step out of the cars feeling squeaky clean and not the least bit tempted; reveling in the 33 mpg average of the return leg of the trip.

Where’s the fun in that?

— Christopher A. Sawyer (The Virtual Driver)