Comments (0) | Add a comment
Diesel better, but is it good enough?
-
Photo Courtesy Wheelbase Media
Diesel engines aren't just for bulldozers and locomotives. This Audi R8 concept proves that although it never saw the light of day as production car.
Tools
FULL THROTTLE
Hey, the 1980s called and they want their diesel engines back. You know what? They can have them. They were stinky, noisy and slow.
There has been plenty of progress since then to improve the diesel in all three of the offending areas, but is it enough to make Rudolf Diesel's invention as popular or more popular than gasoline-powered vehicles? Not likely, but in Europe, because of tax incentives and higher fuel prices, cars and trucks with diesel engines account for about 40 percent of the vehicle population. A Wheelbase Media correspondent who lives in Munich, Germany, bought an Audi A5 with a diesel engine that I absolutely love.
Modern diesel engines have lower noise levels, fire right up on cold mornings, have much more power than they used to and, of course, much more torque than a comparably sized gasoline engine, which is why trucks use them for hauling.
Here in North America, where fuel costs and environmental concerns are increasing, we're looking for new answers to reduce carbon-dioxide emissions, among others, and to save money at the pumps. We don't want gimmicks, we want a sustainable future.
So, we're looking at diesel, and now biodiesel fuel, as viable alternatives to gasoline. They go farther on a given volume while emissions have been greatly reduced in the last few years, especially the sooty particulate coming from the tailpipe. But you have to wonder, is diesel all that much better than gasoline?
Diesel is a fuel processed from petroleum; biodiesel is a less toxic alternative derived from vegetable oil or animal fat. Because of the higher energy per a given volume in diesel fuel and more efficiency in the combustion process, vehicles with diesel engines generally get better fuel economy than gasoline engines and therefore cut down on greenhouse-gas emissions (carbon dioxide). Diesel engines also generally last longer and have fewer parts, meaning lower maintenance costs. Biodiesel engines greatly reduce emissions compared with petroleum-derived diesel and also achieve excellent fuel economy. A combination of petroleum-based diesel and biodiesel is apparently even better than either of them alone.
We know the positive points about driving diesel, but what are the negatives?
Diesel used to have high levels of sulfur, but "clean diesel" has dramatically reduced that to a small fraction of what it was. However, lowering the sulfur levels means lower lubricity levels in the fuel, which calls for more additives. While emissions standards continue to become more stringent to combat pollution and sulfur issues and diesel technology continues to improve, gasoline-powered engines still appear to have the edge when it comes to eliminating these other pollutants.
Diesel engines are not what they were in the 1980s in several ways. Because there are now tougher emissions standards, building them is more complicated (due to additions such as exhaust particulate filters) and production costs are higher. This has driven up the prices of the vehicles, which means buyers are looking hard at the numbers and questioning whether the money saved on fuel will outweigh the (seemingly) higher initial price. Diesel fuel has traditionally been cheaper than gasoline, but now costs more. That diesel requires a more complex refining process to extract the sulfur also adds to the cost.
North American refineries don't produce large amounts of diesel. And what we do produce, we use. Some of our diesel fuel is imported, so, as we produce more diesel vehicles, the worldwide demand will rise, further increasing our costs. And adapting the refineries to produce more diesel will also push up the price, at least in the short term.
Nevertheless, it appears that most of the issues associated with diesel are short term and might be ironed out in the next five to 10 years. The big question is whether we'll even need diesel by the time we've mastered diesel technology. Since automakers can't answer this question, they continue development, while in Europe diesel is just a fact of life.
Diesel choices here are limited to a few from the German automakers, but that's about it. Other carmakers have made noises but have yet to dip a toe in the water. I don't see why not. A Volkswagen Passat diesel we recently tested showed 50 mpg on a flat stretch of 60-mph four-lane highway with plenty of passing power. What's not to like about that?
I'm waiting to see who will offer the first diesel-electric hybrid vehicle in North America. Could 100 miles per gallon really be more than a few years off? For diesel's sake, let's hope not.
Among her numerous accomplishments, Courtney Hansen is the author of her own book, the host of Spike TV's "Power Block," the former host of TLC's "Overhaulin' " and a writer with Wheelbase Media. You can email her by logging onto www.shiftweekly.com and using the contact form.
RSS
Twitter
Facebook
Comments
Terms & Conditions
The following comments are provided by readers and are the sole responsiblity of the authors. The Review-Journal does not review comments before publication nor guarantee their accuracy. By publishing a comment here you agree to abide by the comment policy. If you see a comment that violates the policy, please use the Report Abuse button.
Some comments may not display immediately due to an automatic filter. These comments will be reviewed within 24 hours. Please do not submit a comment more than once.
Note: Comments made by reporters and editors of the Las Vegas Review-Journal are presented with a yellow background.