What do you think of when you hear the word ‘diesel?’ Do you think of a big, loud smelly truck, or a LeMans-winning sports car? Though both exist, the LeMans-winning Audi sports car is a lot closer to the diesel engines found in today’s passenger cars. Though Americans were traumatized by a colossal diesel failure by GM in the late ‘70s, Europeans have embraced diesels for their better gas mileage and durability.

One great example of a modern diesel-powered car is the 2014 Audi A8L. Sharing everything but the engine of the gas powered Audi A8, the A8L TDI turbo diesel V-6 offers all the beauty, performance and luxury of the regular A8. Starting with an attractive full-sized body, the A8 looks the part of a luxury sedan. Inside, a fabulous interior features well-bolstered heated and cooled leather seats, four-zone automatic climate control, and all the electronic goodies one expects in a modern premium luxury car. A video screen pops up from the top of the center console which controls most of the cars functions, but it is controlled by a remote rotary knob instead of a touchscreen; though once you’ve got it figured out, it looks like it should be easy enough to use. It also functions as a screen for the back-up camera, which is enhanced by parking sensors. The power trunk lid opens upon a large and well configured trunk at the touch of a button. The heated power rear seat is the real treat of the A8, where there’s enough leg room for an NBA star, as well as separate climate controls and vents and available DVD screens in the backs of the front headrests. If you’re not traveling too far, it would be a lot more comfortable to travel in the back of the A8 than deal with the hassles of flying.

The 3.0-liter, V-6 turbocharged diesel moves the A8 with alacrity, thanks to its 240 horsepower, but even more importantly, its 406 pound feet of torque. There’s plenty of power throughout the rev band and at any speed. Handling is good for a large car, with nice, tight steering. The most remarkable thing about the diesel engine is how unremarkable it is. That is to say it’s not loud, smoky or slow. But for the hint of turbo lag, most people would be hard-pressed to tell that they’re driving a diesel. A very smooth-shifting 8-speed automatic distributes power to all four wheels for maximum traction. Where you will notice the diesel engine is when you’re passing gas stations. With EPA ratings of 24 city, 36 highway and a cruising rage of about 600 miles, you’ll stop for gas about half as often as you do with a gas-powered car.

Kevin Rodermund, general sales manager at Plaza Audi, says of the A8, “Don’t be intimidated by the diesel engine. It has the power of a V-8 with the gas mileage of a V-6. You can’t even tell the difference from the sound.”

Of course, all this luxury and power doesn’t come cheap at $83,500 to start, but the A8 diesel is in line with other European and Japanese premium luxury sedans and gets much better fuel economy.

Another modern diesel-powered vehicle is the BMW X5, a mid-sized SUV that has decent gas mileage of 19 city, 26 highway from the 3.0-liter, 265-horsepower V-6 twin turbo diesel engine that pumps out 425 pound feet of torque to all four wheels through an 8-speed automatic transmission. Designed more to keep you on the road than to take you off it, the X5 has a classic BMW twin-kidney grill fronting a somewhat sporty-looking SUV.

Heated and optional cooled leather front seats are very comfortable. The rear seat is quite roomy and has its own air vents and temperature controls. There’s plenty of room in the cargo area beneath the electric tailgate which can be expanded by folding the rear seats at the touch of a button. A panoramic sunroof lets in lots of light and gives it an airy atmosphere. The four-zone automatic climate control has its own set of controls on the dash, while most other functions such as the GPS and audio controls interface through BMW’s infamous iDrive system using a dash-mounted screen and remote rotating controller between the seats. If you don’t mind talking to a machine, many iDrive functions can be done through voice control. It has a bit of a learning curve, but once mastered, is said to be relatively easy to use and quite functional.

Due to its prodigious torque, the X5's acceleration is quite good for such a heavy vehicle, with just a moment of turbo lag, and the brakes do a good job of stopping its mass. At highway-cruising speeds, it is quiet and comfortable. Handling is good for an SUV, with only slightly over-boosted power steering and decent road feel. Front and rear park distance control and a back-up camera greatly aid maneuverability when parking.

Gerd Petermann, salesman at Autohaus BMW says, “I like the power of the diesel; it’s always there, and its frugal. It’s a good alternative to the V-8 with all the benefits of the X5 and better gas mileage.”

The BMW X5 will cost you some $57,500 to start. However, if you purchase your X5 for business use, because of its weight, it qualifies for bonus depreciation that can allow you to deduct approximately 75 percent of the purchase price from your taxable income in the year of purchase.

Robert Paster (robertpaster.com) also is an attorney in private practice, concentrating in estate planning and probate.

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