Equipped with Sport Package. the 335d shatters some preconceived notions about diesel during a track day at Watkins Glen.
By David Haueter
Photography by David Haueter
Despite the racing success of the diesel-powered Audi and Peugeot prototypes as well as the earlier BMW 320d, diesel engines and sports cars havent quite meshed in the minds of American driving enthusiasts. Most still think of diesel as more suitable to pickup trucks or tow vehicles, which isnt surprising given the dearth of diesel-powered sports sedans in this market.
BMW has attempted to change that with the 335d, a diesel-powered sedan with the pedigree and performance to please driving enthusiasts. Yet even though it offers the acceleration of a supercar and great fuel economy, (see Bimmer #85), the car is a little disappointing in standard spec. Without the optional Sport Package, it falls short in the handling department once you try to take corners at higher speeds. Push past about 6/10ths and the standard 335d feels like its suspension parts have been replaced with those from a Toyota Camry: Understeer tends to dominate, the handling is sloppy and theres excessive body roll, all of which are all decidedly un-BMW-like.
Sport Package promises to rectify all that by replacing the standard suspension with shorter, stiffer springs and dampers, and by swapping the standard 17-inch wheels and all-season tires for 18s mounted with performance run-flat tires. The package also includes Shadowline exterior trim, more supportive and adjustable Sport seats and a Sport steering wheel that can be equipped with paddle shifters. That sounds good on paper, but would it be enough to make this diesel-powered 3 Series as much fun as one that burns gasoline in its cylinders? To find out, wed need more than just Sport Package. Wed also need a race track, so we checked a 335d ZSP out of the press fleet and headed to Watkins Glen, the challenging road course in upstate New York that once hosted the U.S. Grand Prix for Formula One.
A diesel automatic? On the race track?
Taking a diesel to the track may seem odd here in the U.S., but BMWs 1 Series and 3 Series diesels have been racing in Germanys VLN Endurance Championship on the Nrburgring Nordschleife for a few years now. Their drivers rave about them, and they consistently win their classes thanks to their excellent power delivery coming off corners and longer range between fuel stops.
Alas, our 335d wasnt a race version, and neither did it have a manual transmission. The 335d is only available with an automatic, the ZF 6HP26 that is essentially identical to the 335is 6HP19 TU but is stronger to handle the diesels added torque. Its an excellent transmission, but our track experience with the 335i has shown that these transmissions dont give the driver total control over gear changes despite the Steptronic feature.
We were also concerned about the diesels weight: At 3,825 lbs., the 335d is packing 225 lbs. more than the 335i. Even with 50/50 weight distribution, we feared that the extra pounds would increase the cars understeer, make transitions sloppier and overtax braking performance. We were also a little concerned about exceeding the capabilities of the tires, Bridgestone Potenza RE050As that measure 225/40-18 up front and 255/35-18 at the rear. Theyre fine on the street, but we werent sure theyd hold up to the stresses of a track day underneath such a heavy car.
With those concerns running through our minds, we experienced the highs and lows of diesel driving before we even reached the track. The 335d is exceptional over long-distances on the highway, where the prodigious torque (425 lb-ft) of its 3.0-liter N57 six makes passing slower traffic as effortless as flexing your right foot. The Sport Package suspension keeps the car well composed, providing a good feel for the road without penalizing the driver with a jarring ride over pavement imperfections.
We averaged nearly 37 mpg for the 200-mile trip, most of which took place on the interstate at 75-80 mph. And at the end of our journey, the tailpipe was free of the black, sooty residue typically associated with diesel. Its also worth mentioning that you can stand behind the 335d while its running without smelling any funky diesel fumes.
To fill up the tank before hitting the track, we went searching for diesel fuel once we arrived in Watkins Glen. Only one gas station of the five nearby had diesel, but since its pumps werent working we had to drive ten miles out of town to a truck stop. There, thankfully, one pump had the right nozzle size, though BMW provides an adapter and a pair of gloves in case you have to use the larger truck nozzle. (It would still be a messy affair.) Needless to say, the svelte 335d looked comical filling up next to a FedEx truck.
As soon as we hit the track, we knew within two laps that BMW had done an excellent job of tuning the 335ds Sport Package suspension. Like the 335i Sport, the 335d Sport feels nimble and well-balanced on the track. BMW tunes its suspensions for each individual model, and the 335d doesnt necessarily have the same setup as the 335i. The engineers seem to have used heavier springs or more aggressive shock tuning in the 335d (possibly both), though getting that information out of BMW is like trying to get Warren Buffett to give you his credit card number.
Tons of torque, a quirky transmission
Though the car feels lighter than it really is, if we had to nitpick wed say you may be able to feel the added weight of the 335d in quick transitions like the chicane at the end of Watkins Glens high-speed back straight. Wed have to drive the car back-to-back with a 335i to be sure, and in either case we think the difference is negligible.
Having 425 lb-ft of torque on tap came in handy for negotiating Watkins Glens elevation changes without frequent gearshifting. The track goes downhill through Turn One, then climbs over 60 feet through the Esses that lead onto the back straight. We were able to stick the 335d in fourth gear before turning into the Esses and then ride the wave of torque all the way through, hitting over 100 mph by the top of the hill. Many cars require a downshift in the Esses, which slows the pace and can upset the balance of the car, so it was great to leave it in fourth and concentrate on hitting the apexes.
The momentum we carried out of the Esses allowed us to hit a top speed of around 130 mph on the back straight, which was as fast as wed gone in a 335i before we had to brake for the chicane. In this hard braking zone, the 335ds brakes (which have the same dimensions as those in the 335i) provided good pedal feel and stopping power all day, though we took it easy since we knew we had to drive home at the end of our track session.
Even as we were making fewer shifts than we did in the 335i, we noted that its crucial to keep the 335d in the right gear to make sure its abundant torque is always available. We had to rely on the tach to do so, because the engine is so quiet that we couldnt really hear the sound of the engine well enough to know when to shift.
Once wed figured that part out, the Steptronic automatic makes it relatively easy to keep the car in the right gear, though the transmission is not without its faults. As weve said before, we dont like the 335ds paddle shift arrangement, in which each paddle performs both upshifts and downshifts; we vastly prefer the one-paddle-per-function setup used in the M cars. Most of the other car companies offering paddle shifters (Audi, VW and Infiniti come to mind) go with this more logical arrangement, and we find it exasperating that BMW insists on sticking with a less functional setup merely to differentiate the non-M cars from the Ms.
Fortunately, BMW also provides a shift lever mounted on the transmission tunnel, and we used this instead of the paddles at the track. Unfortunately, the automatic didnt always follow the levers instructions. For one thing, it would shift at 4,500 rpm instead of letting us reach the 5,000-rpm redline. Most of the engines power is down low, so it wasnt a big deal after we got used to it, but it was a little exasperating when it upshifted where it would have been advantageous to hold a gear for the extra revs.
And all day long, the automatic kept shifting from third gear into fourth in Turn Seven, a sharp right that climbs 78 feet uphill on the approach to Turn Eightprecisely where we didnt want the drop-off in torque. Wed downshift from fourth to third and the transmission would go right back into fourth again even though engine speed was well short of 4,500 rpm. We adapted by anticipating it and shifting right back into third, which it would then hold through the rest of the turn and up the hill.
Those quirks aside, we found the 335d quite capable on the race track. To confirm that impression, we put Pete Argetsinger into the drivers seat for a few hot laps. Most recently the driver coach for Formula BMW Americas, Argetsinger has an extensive pro racing background in everything from Formula Fords to sports cars. Whats more, he grew up at Watkins Glen, which his father Cameron built to replace the earlier public road course. Argetsinger was at the track to coach another driver in an open-cockpit Radical, but he was gracious enough to spend a session behind the wheel of our 335d and offer his impressions.
<table width="800" align="center" bgcolor="#ffffff" border="0" cellpadding="0" cellspacing="0"><tbody><tr><tr><td class="rlb" width="345" align="left" valign="TOP"> <!-- _TEXT --> Nimble and agile handling
I know its a BMW, but its a diesel and has a lot of luxury, so I didnt really expect it to feel like a sports car, Argetsinger said. It was so sure-footed and immediately took a set like a race car does, giving you confidence and good feedback right away. It felt very nimble and agile, and it really put the power down well coming off the corners with all the torque it has.
We have to agree, though we think it could put the power down even more eagerly with a dual-clutch gearbox instead of the torque-converter automatic. A mechanical limited slip differential would be nice, tooperhaps one could be offered as a BMW Performance accessorythough we really didnt find the lack of one to be a big issue on the track.
The best accessory, of course, is Sport Package. We cant think of any BMW model in recent history thats better without it, and the 335d is no exception. Even if you never go near a twisty road or race track, Sport Package is worth the money for its excellent seats, meatier steering wheel and the cooler appearance that results from the fitment of larger wheels and lower suspension. (That said, wed love to see this car available with the M Sport options more dramatic cosmetics, or perhaps some of the BMW Performance accessories being offered for the other 3 Series cars.)
More importantly, of course, Sport Package raises handling performance to a level well beyond that of the standard car, making the 335d feel nearly identical to the 335i Sport despite its extra 225 lbs. As Argetsinger noted, its a confidence-inspiring ride, and its diesel engine is impressive.
No matter how its equipped, the 335d isnt likely to start showing up at track days in great numbers. Nonetheless, our day at Watkins Glen proved that the 335d Sport is a very entertaining car, one that would make a fine partner for the occasional track day once you overcome the peculiarities of its automatic transmission. It makes a convincing argument for the idea of a diesel-powered sports car, and it deserves serious consideration as such by those who also want the convenience of an automatic and the infrequent fuel stops that accompany diesel power.
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