The $46,000 Sport Sedan Challenge: State of the Sport Sedan

Whether through sales, performance or reputation, the BMW 3 Series has been the benchmark for sport sedans for generations.

That's a good mountain to stand atop. The entry-level sport sedan is usually the most popular offering for luxury automakers. It often draws buyers into the brand, hopefully staying loyal as they move up in life — and can make larger monthly payments.

When the 3 Series was redesigned for 2012, the company put a new turbocharged four-cylinder under the hood instead of the standard six-cylinder that had powered it for decades.

BMW wasn't alone in this play for improved fuel economy among luxury nameplates. Mercedes-Benz's C-Class swapped out a base six for a turbo four-cylinder. Cadillac introduced an all-new ATS sport sedan with a turbocharged four. And the stylish Audi A4? Well, its turbocharged four has been a favorite of ours for years.

This trend was enough for us to develop a Challenge around it. We also examined the features you should look for in this class and at this price.

This was a Challenge to the 3 Series and to the segment. Were these new engines in the most affordable models that good? What about competitors packing traditional six-cylinder (or even rarer turbocharged five-cylinders) at a similar price? Do only automotive journalists fawn over the 3 Series or would a real shopper choose it as well?

We started out looking at eight cars, but ended up with six:
2013 Acura TL
2013 Audi A4
2013 BMW 328i
2013 Cadillac ATS
2013 Mercedes-Benz C250
2013 Volvo S60

When we decided on the contenders for this Challenge, we knew that both the Lexus IS and the Infiniti G37 were going to be redesigned, so we did not include them. We used Cars.com's listing inventory and the automakers to determine a price cap of $46,000, including destination charges.

We put the cars through nearly a week of testing. We spent a day at the track, driving the cars around a road course that tested them for handling, road-gripping, tight turns, acceleration and, of course, intense braking. We also took them out to the drag strip to get zero-to-60 times, quarter-mile times and 60-to-zero braking distances.

We took them on a 180-mile course that stretched from the valleys to mountains to the desert of Southern California, with lots of twisties, wide-open freeways and surface streets. We used this course to get real-world mileage for each car.

We had the experts spend a day taking each car, back-to-back, around a course that included two freeway segments, rough surface streets and stop-and-go traffic. Finally, we spent a day with a couple who are in the market for one of these cars. Without giving away too much, they left liking a car they were not even considering when they arrived.

Our real-life family members were Jose and Jimmee Medina, young municipal officials working in Southern California cities.

Our experts for this Challenge were:

  • Kelsey Mays, Cars.com's industry editor
  • David Thomas, Cars.com's managing editor
  • Joe Wiesenfelder, Cars.com's executive editor
  • James R. Healey, auto writer for USA Today
  • Brian Robinson, producer for PBS' "MotorWeek"

In some ways, getting to and conducting this Challenge was the most difficult to date (don't ask us about the travel issues). But in many others, it was both the most fun and most competitive. Check out the full results below:

Cars.com's Editor-in-Chief Patrick Olsen contributed to this report.

© Cars.com 04/8/2013