While Range Rovers fit for royalty are the most prestigious products from Britain’s Land Rover, it is their rugged mid-size utilities that are most likely to be found in American driveways. Now to keep that loyalty, Land Rover routinely provides major upgrades. The stepped roof Discovery gave way to a more rectangular LR3 for 2005, and now five years in, designers deemed it time for a new engine, new technology, new interior, and a new name. The Land Rover LR4. Let’s see if all this change is a positive move.

You may not notice much of a difference between the 2010 Land Rover LR4 and its predecessor. It retains the LR3’s squared-off, stepped profile, as well as general size. New styling cues are subtle, like a more upscale front end, smoothed out and brought closer to the top drawer Range Rover. Lighting gains the latest fashion, strips of LEDs daytime running lamps.

The LR3’s lone fender port gets a twin on the LR4. The only place the outgoing model’s asymmetrical styling theme continues is the funky notch in the tailgate glass. Our Izmir Blue LR4 came shod with the new 19-by-8-inch alloy wheels. Twenty-inchers are optional.

But there are bigger changes under the skin. Open the hood to a new all-aluminum 5.0-liter V8 rated at 375 horsepower and 375 pound feet of torque. That’s 25% more horses and 19% more torque than last year’s 4.4 V8.

The only transmission is an upgraded ZF six-speed automatic with sport manual mode. We found it to be well-matched to the Rover’s added power. Shifts are smooth and satisfying.

Off-roading is at the core of Land Rover DNA, and the LR4 is the most intrepid vehicle in the Land Rover’s U.S. model range. Revisions to the sophisticated Terrain Response System provide a higher degree of versatility. Sand Launch Control is new, and Rock Crawl can now automatically apply the brakes in precarious low-speed situations.

Our biggest complaints with the LR3 were slow shifts and a lack of power at the top end, but the LR4’s V8 is smooth and torquey across its entire powerband. Zero to 60 is a fine 7.5 seconds, a half better than our last LR3. So, there is ample passing power for broken lines and yellow lights, and plenty of low-end grunt for steep grades.

The LR4’s other notable mechanical bits include a multi-setting electronic air suspension, new chassis components, and bigger brakes. Towing tops out at a capable 7,700 pounds. Our tester’s Heavy Duty Package includes a locking rear diff for when things aren’t going right, and a full-size spare.

We liked the view from the LR3’s airy cabin just fine, but the dash left quite a bit to be desired. For 2010, the center stack and console feature more ergonomically correct controls, and much more pleasant styling.

Soft-touch materials are everywhere, from the dash pad, to the stitched multi-function steering wheel, to the leather-rimmed seats. Bolder seat contours make for a more comfortable cabin, too. Gauges remain large and clear, under a deep hood to protect from glare. Our HSE Plus adds satellite navigation, along with three-row, seven-passenger seating.

We like the raised position of the second row split bench, although there could be more legroom. The third row, however, is hard to get to and really only suitable for small children.

One of the design features that gives the LR4 such off-road prowess is a short rear overhang. But that also limits luggage space. Open the split hatch for only 9.9 cubic feet behind the third seat. Fold it down for a more respectable 42.1 cubic feet, with a class competitive 90.3 after all seats are down.

Less respectable are Government Fuel Economy ratings of only 12 city and 17 highway on premium gas. The new V8 is just as thirsty as the old one. But, according to Land Rover, tailpipe emissions now meet ULEV2 regulations.

Still, the LR4’s Energy Impact Score is very high, 24.5 barrels of oil consumed annually, and leaves a 13.1-ton Carbon Footprint wherever it goes. Those numbers are the same as the Mercedes-Benz GL550, which doesn’t soften the environmental blow at all.

Yet given all it’s attributes and luxury, the base LR4 well priced at $48,100. That’s over $35 grand less than the GL550. Even the higher featured HSE at $51,750, and top-shelf LUX at $57,665, look good by that measure.

Land Rover’s new 5.0-liter V8 is a much better match for the LR4’s mass, and for 2010, Terrain Response is a good thing made better. That, plus a host of other improvements really do make the LR4 worthy of a new name, despite appearances. The LR4 upholds the Land Rover heritage well, adding more refinement and comfort, without losing any of its off-road moves.

It’s a fun, enjoyable ride that lets you know what you’re in for right away with a nice raspy exhaust note at start up.