Wednesday, July 16, 2014

The Diesels Are Coming! The Diesels Are Coming!

Rudolf Diesel's engine has had a rough time gaining much more than limited commercial acceptance in America. Widely popular with trucking companies for their monstrous torque and million-mile durability and with railroads for their greater efficiency and less maintenance over steam, the clattery compression-ignition engine is viewed as a novelty to a majority of American motorists. Derided as smelly, noisy, and slow, diesel cars sold in America have never been very popular with the Volkswagen Golf and Jetta TDI often being the only diesel-equipped family cars, frequently sold without competition although the tides appear to be changing.

My current job maintains a fleet of some three hundred mini-buses, all of them diesels. The newest ones are a Chevrolet chassis motivated through life by GM's latest Duramax diesels while the older buses are Fords equipped with the venerable 6.0 liter Powerstroke. Although they are durable with many older examples showing close to 300,000 miles, the Powerstroke engine is exactly what the average American consumer thinks about when somebody utters the words 'diesel engine'. They're uncomfortably noisy when you're on the outside, even at idle, they smoke considerably when cold and take an eternity to come up to temperature when the thermometer drops. Finally they lack the oomph of a gas equivalent chassis. The Duramax, on the other hand, starts and runs like a gasoline engine and is so quiet that you can even hear the turbo spool up under throttle. I've yet to see one smoke thanks to the exhaust fluid after-treatment and even though they've been tasked with hauling a vehicle weighing around 20,000 pounds fully loaded, they're no slouch off the line. However, there are drawbacks. During a cold snap this past winter when we were starting buses in temperatures close to zero, the Chevys would require six or seven glow plug warming cycles before coming to life while the Fords were cranking over first time out albeit with a longer glow plug warming times (around ten seconds). Despite this, engines like the Duramax diesels powering our newest buses are the future of diesel engines.

While public perception and inherent flaws of the diesel engine kept all but the most astute stingy buyers away from the rare US market offerings, emissions regulations did the rest to keep the remainder from even reaching showrooms. As emissions standards grew increasingly strict, import manufacturers began to refrain from providing them at all as the size of the market would never allow them to recover the costs to bring them up to spec. As a result, the availability of diesels has been restricted to larger cars with higher profit margins such as the Mercedes E-Class with the exception of the aforementioned Golf and Jetta. Currently the only diesel car available for under $30,000 in the United States outside the VW family is the Chevrolet Cruze 2.0 TD.

Now anyone over the age of fifty will likely remember what happened the last time GM tried to put a diesel engine in a passenger car in this country and is probably already cringing. For those who don't, it was such a disaster that it made the Titanic's maiden voyage look like a Hollywood success story. Rather than starting from scratch and constructing a purpose-built diesel engine, the general had what must have seemed like a great idea at the time and took the Oldsmobile 350 Rocket engine, made some tweaks and voila! Instant diesel power. What resulted was one of the most awful diesel engines ever made and served only to turn several generations off of diesel engines for good. As diesels operate off compression and not spark, their connecting rods, head bolts and studs associated with the big boom have to be considerably stronger but GM simply used the parts from the gas model with predictable results. Engines began warping heads, cracking head gaskets and causing hydrolock and when repaired like a gasoline engine, the problem went uncorrected for the rest of all time. Couple the atrocious reliability with acceleration times matching that of the average glacier (around 16-21 seconds to sixty for the worst offenders) and it's not hard to understand why older folks cringe and yell out, "WHY?!" when I tell them my friend just bought a Chevy Cruze with a diesel engine.

But there's no need to fear. The diesel engine in the Cruze is the real deal, straight out of GM Europe, a continent that knows a thing or two about diesel power. At idle it is a little clattery but certainly nothing like that of a 1980 Oldsmobile Cutlass Wagon Diesel which sounded a bit like that corner of a rest stop reserved for semi trucks of the same era. But once you're on the move, there's nothing to indicate what's going on under the hood. In addition to being quieter, the Cruze Diesel is quick at right around 8.5 seconds to 60 mph and gets amazing fuel economy. On a brief stint on US-26 with the cruise control set at 55, I saw a steady 64 MPG average over just a few miles. Now whether that could be maintained on a longer drive remains to be seen but one GM engineer claimed to have gotten over 900 miles out of a tank on a Cruze Diesel and I for one don't see any reason to believe he's lying. In terms of evolution, GM's 1970s diesels were the little amoebas found in pond slime while the two liter four pot in the Cruze is Scarlett Johansson. It's smart, pretty, ambitious and everybody is sure to want it when they find out their neighbor got one.

What allows the Cruze to meet stringent American (read: California) emissions standards is a small plastic tank that occupies the space in the trunk that would normally snuggle the spare tire. Contained within the tank is seven or eight gallons of a urea after-treatment (called Diesel Exhaust Fluid or DEF in the industry) sprayed into the exhaust at intervals to keep it squeaky clean. As of present, this system is only widely found in North America but is slowly finding its way around the world and as of 2018, European diesels will have to meet the same emissions requirements as the American ones. While DEF systems are not the only answer to meeting American standards (current VW and Audi TDI models sold here rely on whiz-bang German ingenuity), the making of equals means Americans longing for the diesels offered in Europe will finally begin to see them trickle across the Atlantic and into America's cities and suburbs. Ford, Honda, Hyundai, Kia, Nissan, Toyota, Volvo and more all offer cars with one or more diesel choices in Europe and though it's almost a guarantee we won't see all of them here, the diesel landscape is looking more promising now than it has in probably ever and I for one can't wait.


Passenger Cars and SUVs Currently Sold in the US with a Diesel Engine Option

Audi A6
Audi A7
Audi A8
Audi Q5
Audi Q7
BMW 3-Series
BMW 5-Series
BMW 7-Series
Chevrolet Cruze
Jeep Grand Cherokee
Mazda 6 (currently awaiting emissions approval)
Mercedes-Benz E-Class (sedan only)
Mercedes-Benz GL-Class
Mercedes-Benz GLK-Class
Mercedes-Benz M-Class
Porsche Cayenne
Volkswagen Golf
Volkswagen Jetta / Jetta Sportwagon
Volkswagen Touareg
Volkwagen Beetle (only diesel convertible available in the US)
Volkswagen Passat