It’s hard not to wear a broad grin while driving Audi’s 2014 A6 TDI. One of a growing array of upscale TDI models in the Audi stable, the $57,500 A6 TDI presents a compelling case for premium mid-size sedan buyers to go clean diesel. Time behind the wheel illustrates the well-balanced nature of the A6 TDI, which artfully blends luxury, comfort, performance, and efficiency in a very desirable package. Plus, it’s just fun to drive.

The A6 TDI’s 3.0-liter turbocharged direct injection V-6 is surprisingly quiet and smooth, dispensing with the two inherent challenges that diesel as a whole has faced in attracting U.S. buyers in the past. Ride quality, handling, and overall driving characteristics are excellent. The A6 TDI is powerful, with strong low-end torque pressing you back in the seat with ease while delivering 240 hp and an impressive 428 lb-ft torque. All this power is channeled to the highway via an 8-speed tiptronic transmission and quattro all-wheel drive. Acceleration from 0-60 mph is achieved in a quick 5.5 seconds.

This level of power-at-the-ready does not sacrifice efficiency as one might expect, particularly in highway driving as the model achieves a rather impressive 38 mpg. Total driving range of over 700 miles is possible. The TDI clean diesel’s inherent efficiency is bolstered with other efficiency measures including a relatively lightweight chassis and aluminum body panels, plus a start-stop efficiency system that shuts the engine down under specific conditions such as extended idling or at stoplights. The engine restarts instantly when a driver releases the brake pedal.

Driving performance and efficiency are just part of the story with the Audi A6. This model makes a point of enveloping driver and passengers in a luxurious and accommodating interior, paying great attention to detail throughout the cabin with a curved wraparound dash, fine leather, and high-end materials. Instrumentation and controls are well placed and intuitive.

Infotainment and connectivity features are extensive with MMI Navigation plus and Audi connect, which offers Google Earth mapping and in-vehicle Wi-Fi connectivity for up to eight wireless devices. Available are an array of sophisticated features including night vision assistant, heads-up display, and Audi pre sense plus, the latter system helping to detect imminent collisions and initiate protective measures.

The A6 TDI presents a very upscale exterior with sharp lines and unmistakable Audi design cues, among these Audi’s signature LED lighting technology. Add in efficient and responsive TDI power and the package gets even more compelling.