DETROIT – Jaguar Cars Design Director Ian Callum is enjoying a newfound freedom under the ownership of Tata Motors Ltd., the Indian auto maker that purchased the iconic British brand from Ford Motor Co. last year for $2.3 billion.

Tata has left us to our own devices to get on with what we’ve done,” Callum tells Ward’s at the North American International Auto Show here.

“The biggest difference is we kind of turned around one day and found we were on our own. It took a little while for people to get on board that we’re in charge now. There’s nobody at Ford North America or Ford of Europe to come and make judgments on us,” he says.

Under Ford ownership, Callum says approval of his designs would take weeks, a process that is completed in mere hours under the auspices of Tata.

But he is careful not to lay blame on Ford. “It’s nobody’s fault. That’s just the way it was.”

An additional benefit of Tata ownership is that Chairman Ratan Tata is a big fan of design, Callum says. “He gets involved in conversations about design and about what we have on (our) desks and in the studios.”

The first car Jaguar offered under Tata ownership is the ’09 Jaguar XF sports sedan, although the majority of the work on the vehicle was conducted under Ford guidance.

The XF will serve as the basis of Jaguar’s new design DNA, as the brand tries to create a “family resemblance” within its showrooms.

“I want some references across (the lineup) that gives a sense of being part of that family,” Callum says. ‘I don’t want twins, but brothers and sisters.

“What we don’t want to do is what we call the ‘cookie-cutter’ approach, where you have a small car, medium car and big car all on the same design, and you have to look twice to tell which one it is. I think there is room for making cars that are different enough even in the same family.”

While Jaguar did not introduce any all-new vehicles at this year’s Detroit show, it did display the ’10 XK and “R”-badged performance versions of the XK and XF.

The XFR is powered by a new 5.0L direct-injection supercharged V-8 engine delivering 510 hp and 461 lb.-ft. (625 Nm) of torque that is capable of 0-60 mph (97 km/h) in a scant 4.7 seconds.

In addition to the new engine, the XFR features new sill extensions, hood louvers and a rear bumper with a unique body-colored lower spoiler incorporating the “R” badge.

Callum says he was careful not to make the rear spoiler too noticeable. “I wanted to make it as small as possible, not over the top. It’s as big as it needs to be to work.”

The car also boasts quad tailpipes, new seats with extra bolstering and 20-in. alloy wheels.

The aluminum-bodied ’10 XKR, which comes in both coupe and convertible versions, also boasts the new 510-hp supercharged mill, as well as revised exterior styling and new interior trim.

Base versions of the XF and XK get a new normally aspirated 5.0L V-8 engine that produces 385 hp and 380 lb.-ft. (515 Nm) of torque. A diesel mill is optional on both vehicles in most European markets.

Callum says designing the “R” performance editions is difficult, as consumers who purchase such cars don’t want overly flashy design.

“(Customers) want just enough in the car that aficionados will recognize what it is,” he says.

Meanwhile, plans are in the works for a new small sports car, although the project has yet to be given the green light.

While he has “no shortage of ideas” for the new vehicle, Callum says not to expect it to emulate the iconic Jaguar E-Type from the 1960s.

“I don’t think I am able to design a car that’s as beautiful as the E-Type,” he says. “If you like the (original) E-Type, then buy an E-Type. It’s that simple. Don’t expect another one.”

bpope@wardsauto.com