CHARLESTON, SC – In the first-quarter sales race for luxury-vehicle supremacy in the U.S., Daimler AG’s Mercedes-Benz marque trailed perennial champ Lexus by 236 units.

Not that anyone at the tri-star brand is counting. Because they’re not.

The luxury-vehicle market “is not a numbers game,” says Ernst Lieb, president and CEO of Mercedes-Benz U.S.A. Inc.

Delivering products worthy of Mercedes’ iconic reputation is its own reward, Lieb tells Ward’s. And the pursuit of claiming the No.1 sales spot “is just an ego thing.”

His cool confidence belies the fierce competitiveness that defines today’s U.S. luxury market. Recall woes raised doubts about Lexus quality, compelling parent Toyota Motor Sales U.S.A. Inc. to launch aggressive incentives that bumped up the brand’s March sales by 6,432 units.

That result sparked a 35.4% jump compared with prior-month and pushed Lexus’ first-quarter delivery total to 49,523.

But Mercedes kept up with 49,287. And it did so without responding to the Lexus incentive push.

“We don’t want to play any games,” Lieb says. “We are very happy with the numbers. Our target was way lower.”

He does not disclose the target.

Mercedes’ first-quarter sales tracked well ahead of the industry trend. Led by its C-Class and E-Class models, Mercedes car deliveries swelled 23.6% compared with like-2009, while the GLK cross/utility vehicle’s growing popularity spurred light-truck sales 29.5%.

Industry car and truck sales rose 18.2% and 12.9%, respectively.

“We strengthened our position,” Lieb says, noting Mercedes increased its market share by 0.1 points in each segment. The tri-star brand’s first-quarter share of the U.S. car and truck market was 2.5% and 1.5%.

Meanwhile, Lieb is unfazed by Mini’s plans to expand its already strong lineup. At the recent New York auto show, BMW AG’s Mini brand unveiled the Countryman, a diminutive-yet-robust CUV set to arrive on U.S. shores in February 2011.

Against this backdrop, Daimler announces a tie-up with Renault SA-Nissan Motor Co. Ltd. that has implications for small-car development.

Lieb says he has no knowledge of any Mercedes plan to launch a Mini Cooper-fighter. And he has no intention of exploring the notion.

Pointing again to Mercedes’ most recent sales results, Lieb asks: “Do I look worried?”