2014 BMW 328d xDrive Wagon Long-Term Update 2
Why Diesel? It's the Fuel Economy and Range
The 2.0-liter turbodiesel under the hood of the 328d wagon asks $1500 over its gasoline-powered equivalent. Knowing this, you might wonder, "Why diesel?" What do you get for that premium?
For starters, diesel's higher energy content means a quite substantial improvement in fuel economy. Rated at 31/43 mpg city/hwy, the diesel gains 9/10 mpg over the gasoline car's rating. On top of that, gas-powered BMWs require premium fuel,and it's more expensive than diesel according to current national averages. Using figures of 15,000 annual miles and current average fuel prices, the 328d's fuel savings versus the 328i total roughly $650 a year. That means recovering the premium paid for the diesel takes a little more than 2 years, a short amount of time when compared to how long it takes to recover the premium paid for some hybrid powertrains.
Despite having a fuel tank 0.8 gallon smaller than the 328i (that space is reserved for Diesel Exhaust Fluid), the fuel economy advantage also means the 328d can go 114 miles farther per tank. I see more than 500 miles on the range display after most fill-ups, which is a pleasant sight. During a recent trip to Sacramento, the range estimate showed more than 600 miles, meaning I could make the drive without having to stop for fuel. I wish my bladder were as efficient.
The trip provided a good opportunity to test BMW's Eco Pro mode. I drove north as I would normally, with the drive mode set to Comfort and with cruise control on. That trip netted 36.2 mpg, which isn't bad considering the high average speed I maintained. On the way back to Los Angeles, I drove the same way, but in EcoPro. Accessed through the drive mode selector toggle, Eco Pro makes the car behave more economically, with a softer throttle, less aggressive shifting, and reduced air conditioning, among other things. It encourages efficient driving with a ticker that counts miles saved and by scoring your traffic anticipation and braking. I tried following the guides, but quickly reverted back to how I normally drive. Even so, on this trip, I averaged 42.3 mpg. With a two-way average of 38.9 mpg, I'm happy with the 328d's fuel economy.
My impromptu test was hardly scientific, but that's why we have Emissions Analytics. In its regimented tailpipe sniffing test, the 328d returned 29.8/44.2/34.9 mpg city/hwy/combined. Though its city mpg falls slightly short of the EPA's rating, the 328d makes up for it on the freeway and ultimately matches the combined rating. Either way, the diesel makes a strong case for itself.
|Service life||7973 mi|
|Average fuel economy||0.66 lb/mi|
|CO2 emissions||33.5 mpg|
|EPA City/Hwy/Comb Fuel Econ||31/43/35 mpg|
|Energy consumption||101 kW-hr/100mi|