Video: 2014 Audi A8 L TDI

And that is a new diesel engine. Now diesel doesn't have a very luxurious ring to it. And it's also common in small, inexpensive, compact cars. One thing worth mentioning right off the bat, is that the A8 L TDI's fuel economy is as good as a midsize sedan with four-cylinder engine. And it just gets better from there. The Audi A8 diesel's fuel economy is great. It's 24 miles per gallon in the city and 36 miles per gallon on highway. Audi says that's higher than its competitors, which include the Lexus LS600 hybrid and Mercedes S350 diesel. I spent around 300 miles in the car, and I average 30 miles per gallon with an average speed of about 32 miles per hour. That's crazy. This is a 4,500 pound sedan. There's no way that you get that good fuel economy, but it does. And it's very easy to do so, in the real world. Great mileage isn't the only advantage here. It's quiet, smooth, and the power comes on strong and linear, unlike many diesel engines that peak and then fall off at higher RPMs. The 3.0 liter V6 makes 240 horsepower and 406 pound-feet of torque. And it doesn't have as much fall-off as other diesel engines at higher RPM. The A8 suppresses engine noise so well, that you'll only hear a faint turbocharger whistle and a little bit of diesel chug with the windows down. But when the window is up, you can't even tell there's a diesel engine underneath the hood. Like other A8s, the TDI allows you to customize the driving experience with various suspension firmness settings, ride height settings, as well as engine and transmission and steering responsiveness. Now, I prefer to keep all of these settings in the comfort mode. It's where the A8 shines. It's comfortable, it's quiet, it's a really nice highway driver. In sport mode, it's not a sports car and that's even with these optional 20 inch summer tires that are equipped on this car. The A8 really shines when it's in comfort mode. And that's where I kept it. One more reason I left it in comfort all the time, is because it's not the easiest to switch between the sport mode, the comfort mode and all of the individual settings that you can configure. It's, you have to enter it through the car menu here, and then with the dials. There isn't a sport button or a comfort button on its own. Our $100,000 tester has a lot of standard equipment and a lot of optional equipment. We have the Bang & Olufsen stereo with tweeters that pop up out of the top. It's an okay stereo, not as good as we remember in some of the earlier A8s, but we also have a heated steering wheel, heated seats, cooled seats, rear windows with power sunshades, rear window with power sunshade. The rear panoramic sunroof tilts up and has its own shade as well. There's excellent massaging seats that are great in traffic. Although we wish they were a little bit more aggressive. There's also a suspension that lowers, that looks really, really good when lowered. Easy to get out of, easy to get into and also it raises to clear tough curbs. In addition to those features, you also get the A8 L platform. That's the only model the diesel comes with, and that's the extended wheelbase. So you have a ton of extra room in the back. Up until this diesel offering, Audi has had a hard time making the A8 stand out against its competitors. And part of the reason was its trunk space. In the back, you only have 13.2 cubic feet of cargo space, and that's less than a Hyundai Elantra sedan. (car trunk clicking) Audi demonstrates with its A8 L TDI that luxury buyers don't have to be afraid of the word diesel, but the bigger question is, are buyers who are spending upwards of $80,000 on their luxury car, really concerned about their monthly fuel costs? If you are, then the A8 L TDI is one of the best options out there. One more thing to remember, if you're buying a diesel, you might be stuck behind a long line of landscaping trucks in the morning, when you need to refuel. The good thing about the A8 is that it has a maximum range of over 850 miles. So you won't have to be doing that too often. (gentle music) (engine revving)