NOT THE DIESEL thing again.
Believe me, if I could, I would just avoid even mentioning the fact that the BMW 535d burns diesel fuel instead of premium gasoline. Why? Because you don’t get the crazy email I get, OK? Diesel advocates, the true believers, scare me. They have an agenda and dwell in tunnels between gas stations.
No, please! I’m not interested in your spreadsheet on the “diesel-payback period,” the time it takes to recoup in fuel savings the additional cost of a diesel powertrain. Thank you for the picture of your uncle’s million-mile 1983 Mercedes-Benz diesel S-class. Think of all the traffic he held up.
For the benefit of regular folks, let me translate the diesel weirdos’ argument: Diesel engines offer higher mileage, more torque and lower greenhouse emissions. Diesel engines are generally more durable than gas engines, and, consequently, diesel vehicles hold residual value better. And then there’s modern diesels’ graceful, unstrained athleticism, as keenly exemplified in a turbocharged compression-ignition showboat like our test car, the 2014 BMW 535d xDrive sedan.
Diesel. Yeah. And if you ever want to read a heartbreaking story of smart, sad guy, seek out Rudolf Diesel’s biography. Sheesh.
It’s been seven years since low-sulfur diesel fuel (a key enabler of clean diesel) became widely available in the U.S. Before that, diesel passenger cars had become functionally extinct, unable to comply with California’s air-quality standards on particulate and nitrous-oxide emissions.
Even with low-sulfur fuel, U.S.-market diesel passenger cars require advanced particulate traps and often, in the case of larger engines, post-combustion exhaust treatment, typically using a urea-based fluid called AdBlue. This fluid is stored onboard and replenished at service intervals (though Mazda and Honda both sell diesels clean enough to forego post-combustion treatment.)
These systems constitute diesel’s upfront cost to the consumer, the diesel premium. As compared with a nearly identical, gas-powered BMW 535i xDrive sedan, the 535d costs an additional $1,500 ($60,100), a roughly 2.6% premium over the gas model. It’s not a question of whether your operating costs will ultimately be lower—they will—but exactly when those lines will cross.
Diesel advocates, the true believers, scare me. They dwell in tunnels between gas stations.
Battery-based hybrid systems also improve net vehicle efficiency, and they also cost extra. But diesel advocates note—usually at dinner, when you can’t get away—that diesel is actually a more economical route to higher efficiency than battery hybrid.
Fuel cost? Well, that’s interesting. While it is true that a gallon of diesel costs around 35 cents more than regular unleaded, most cars in the 535d’s bracket burn premium unleaded, which is typically on par with diesel, price-wise.
See, diesel freakazoids? Are you happy now? It’s boring.
An enduring mystery to me is why Americans don’t care. Diesel market penetration continues to bump along the bottom in the U.S., at just over 3% in 2013. And this year there is a Noah’s Ark of awesome diesels arriving from Germany. Lots of Audis and BMWs with four or more seats can be had with a diesel-engine offering. You know, lovey, the boys at the lodge will just be hatin’ it!
2014 BMW 535d
Base price: $58,900
Price, as tested: $68,750
Powertrain: Turbodiesel 3.0-liter DOHC, 34-valve inline six with variable-geometry turbocharger; eight-speed automatic transmission with manual-shift function and sport mode; full-time-all-wheel drive
Horsepower/torque: 255 hp at 4,000 rpm; 413 lb.-ft at 1,500 rpm
Length/weight: 193.4 inches/4,255 pounds
Wheelbase: 116.9 inches
0-60 mph: 5.7 seconds
EPA fuel economy: 26/37/30 mpg, city/highway/combined
Trunk capacity: 18.4 cubic feet
As for durability, can I share something with you? I’ve been to Le Mans eight times. Seven times, a diesel-powered Audi prototype has won (11 victories overall). Ninety-nine-point-nine % of all motorsports marketing is horsefeathers, but I’ve never seen a diesel race-engine break. I’ve seen the turbochargers melt and have to be replaced—in the middle of the night, an unbelievable spectacle—but I’ve never seen an Audi diesel race-engine, as technicians say, soil the bed. That has to mean something, right?
Join me in a thought experiment: We are choosing between two cars. On the one hand, the BMW 535i xDrive sedan ($57,650 MSRP), with a 3-liter, 300-hp, inline turbo-gasoline engine returning 29 miles per gallon nominal on the highway. And, remember, we’re talking about a BMW petrol inline six, so hugely refined, ridiculously smooth, like, where do you put the bobbin?
On the other hand: the very same car but with a 3.0-liter turbodiesel putting out 255 hp and getting 38 mpg on the highway ($58,900). This is no run-of-the-mill smudge pot, either. The all-aluminum 24-valve DOHC inline six breathes by way of a variable-geometry turbocharger and common-rail direct injection. The diesel also has an absurd advantage in torque: 413 lb-ft. at 1,500 rpm, as compared with the gasser’s 300 torques.
Like the 535i, the diesel puts the power down via an eight-speed automatic transmission, the control software for which is really responsible for making this low-revving turbodiesel behave like any other BMW six.
On the street the 535d’s acceleration is a just a touch more deliberate (5.8 seconds as compared with the gas-burners 5.5), but once under way, the turbodiesel’s burly athleticism cannot be denied. Three taps of the rev limiter and the 535d is at autobahn speeds, warmly warbling and tracking like a laser beam. Again, part of what is supposed to make the U.S. car market unique is its greater average distances driven, and long-distance efficiency is what diesels do best. So why so little love?
Now, in our thought experiment, everything else between our BMWs is the same. The same strength in cabin materials, the same sober richness of design, the same rock-solid feel. Same car. At the upper end of the punch list, these cars can get appealingly rowdy, with optional integral active steering (four-wheel steering) and lightweight 19-inch wheels, and a vast palette of colors and trim packages to make your car like Rocco’s Hideaway.
Which one? It’s a trick question. There really is no difference, except that, in the long run, the diesel is cheaper to own. Indeed, that has been the whole point of BMW’s diesel powertrain program: to make diesel transparent to driver/owners long accustomed to gasoline powertrains and BMW’s classic sporting character.
In that, the BMW 535d has succeeded wildly, with a diesel power plant (peak horsepower at 4,000 rpm) that is as punchy and free-revving as a gasoline engine, quiet and nearly free of shake, and just flat out hossy and powerful any time it’s asked.
With the 3.0-liter’s ultraprecise direct fuel injection and other advanced diesel trickery, four out of five blindfolded car salesmen couldn’t tell the difference.
And compared with the dragon’s butthole of your average late ’70s diesel, the 535d’s exhaust is minty fresh.
Well, now you know. You’re well armed to go to the dealership. Diesel, man.
Tell ’em Rudolf sent you.