BMW has rethought its 3-Series diesel strategy for 2014. Will this new high mpg 328d be a hit?

BMW's previous-generation 3-Series diesel, the 335d, was nothing short of a torque monster. With 425 lb-ft of twist on tap from a twin-turbo inline-six, it had enough low-end muscle to make mincemeat of merges, handle passing situations with aplomb and seemingly even accelerate the earth's rotation.

But the sedan was also the most expensive non-M model in the 3-Series lineup, and its fuel economy, though respectable given the prodigious output, didn't quite reach the lofty heights that many have come to expect from an oil-burner.

For the follow-up to the 335d, BMW has chosen to completely rethink its diesel formula. Instead of a potent but less efficient six-cylinder, the new 328d utilizes a four that promises to significantly boost mileage while also allowing for a more affordable starting price.

In theory, the 328d seems poised to offer an ideal balance of performance and efficiency, but does it deliver? To find out, we journeyed to BMW's North American headquarters in Woodcliff Lake, New Jersey, for a brief preview drive.

Downsized Diesel

Plucked from BMW's European engine portfolio, the 328d's four-cylinder is a direct-injected 2.0-liter unit that's force-fed air by a twin-scroll turbocharger with 22 psi of peak boost. It produces 180 horsepower and 280 lb-ft of torque at 1750 rpm - meaning it gives up 85 ponies and a full 145 lb-ft to the 335d's larger mill.

The new motor's big advantage, of course, comes in the realm of efficiency. Whereas its predecessor returned 23 city/36 highway mpg, BMW estimates the 328d will be good for at least 28 city/40 highway mpg; one executive even suggested that the highway figure might be as high as 45 mpg. Final EPA ratings are expected soon.

With a 16 gallon fuel tank onboard, the 328d should be able to travel at least 640 miles on the open road before needing a fill-up. A urea-based exhaust after-treatment system - necessary to meet emissions standards - will also require replenishment, but only every 6,000 to 10,000 miles. BMW says it will include the after-treatment with its four-year maintenance program.

Just one transmission will be available in the United States - a ZF eight-speed automatic. Lucky European motorists can also spec a six-speed manual with extra-wide, economy-focused ratios, but BMW says that there isn't enough volume potential to justify bringing the stick stateside.

On the other hand, the 328d will be offered on our side of the pond in several different bodystyle and drivetrain configurations, unlike the sedan/rear-drive only 335d. Buyers will be able to choose from sedan and wagon variants, and BMW's xDrive all-wheel-drive system can be spec'd to increase the diesel's appeal in northern states. It's optional on the sedan and standard with the wagon.

Within the 3-series lineup, the 328d will be positioned between the gas-powered 328i and 335i models with a price that should start just south of $40,000. Standard features and available options packages will mirror those of the 328i.

On the road

In terms of outright speed, the 328d is merely average - BMW reckons it will hit 60 mph from a standstill in about seven seconds. But it's not meant to be a track-ready rocketship. Instead, thanks to the plentiful and readily available torque, it's an excellent tool for conquering everyday driving situations - scooting past dawdling drivers and merging from a stop into speeding traffic are effortless affairs.

Despite its abundance of cogs, the eight-speed always seemed to smoothly and unobtrusively select the right ratio. Paddle-shifters are available, but we think buyers would be better served by spending their options budget elsewhere.

A hint of diesel soundtrack is audible at idle, but it doesn't seem terribly out of place in a luxury vehicle given that many direct-injected gasoline engines exhibit a similar mild clatter.

Leftlane's bottom line

At first blush, the 328d seems like it hits all the right notes, offering excellent mileage with just enough grunt to keep a commute interesting. It won't win over power-hungry enthusiasts like the 335d, but it's also much better positioned to appeal to a broader range of drivers.

We look forward to getting behind the wheel again for a more thorough test after final pricing and fuel economy details are released.

Words and photos by Nat Shirley. Some photos courtesy BMW.