The 2016 Lexus RX 350 (I give it four out of four stars) is likely to continue the luxury SUV’s track record of sales leadership.

When it went on sale in 1998, the first RX defined a new kind of upscale SUV intended for on-road use rather than towing and off-road excursions. Lexus has sold 2.1 million RXs, a figure that makes other luxury brands envious. Competitors focus obsessively on the RX when they develop new luxury SUVs.

The new, fourth-generation RX is likely to remain the best seller, thanks largely to high fuel economy and Lexus’ seemingly permanent position atop studies of quality and customer satisfaction.

Still, I was struck by a distinct lack of technical and design leadership in the loaded, all-wheel-drive RX 350 F Sport that recently carried me in comfort more than 600 miles from the hills of Appalachia to the shores of the Great Lakes.

With the exception of a couple of poor controls, the RX gave me nothing to complain about, but it failed to demonstrate any new or exciting features.

The 2016 RX is longer and wider than the SUV it replaces. Its styling borrows mildly from the polarizing, smaller NX SUV, but takes few chances other than its hour-glass shaped grille.

The profile appears lower and sportier, although the SUV’s height is unchanged from the previous model. Rising horizontal lines along the RX’s sides and black C-pillars make the roof appear to float.

Gasoline-powered RXs come with a 295-horsepower 3.5-liter V-6 and eight-speed automatic transmission. Prices for a front-drive model start at $41,900. All-wheel-drive raises the base to $43,300.

The high-mpg hybrid RX 450h combines a less-powerful 3.5-liter V-6 with electric motors for a total of 308 horsepower. Prices start at $52,235 for front-drive and $53,635 with AWD.

I tested a well-equipped RX 350 AWD with the F-sport package, Mark Levinson audio, navigation, voice recognition, Bluetooth phone and audio compatibility, adaptive cruise control, blind-spot and lane-departure alerts, leather upholstery, heated and cooled front seats and more.
It stickered at $53,385. All prices exclude destination charges.

The RX competes with midsize luxury SUVs like the Audi Q5, Acura MDX, BMW X5, Cadillac SRX, Infiniti QX70 and Land Rover LR4. The Cadillac XT5, which replaces the SRX next spring, and upcoming Jaguar F-Pace and Mercedes GLE are about to join the pack.

The RX presents a solid value. The vehicle I tested cost about the same as similarly equipped competitors.

The interior was roomy and comfortable. The passenger and cargo compartments are among the roomiest in its class. The front seat provides plenty of shoulder, leg and head room. There’s also a deep storage bin and other storage spots. Soft materials covered the dash and door tops.

The voice recognition for phone calls and navigation is less accurate and requires more steps than the best competitors. A joystick on the center console that controls many functions, including audio and navigation, is distracting and difficult to use in a moving vehicle.

Happily, the RX provides traditional buttons and knobs for some audio and climate controls.

The V-6 has about 25 more horsepower than the previous RX. Its 295 horsepower is about average for the class. An eight-speed automatic transmission helps deliver satisfying acceleration.

Shifts are nearly imperceptible, with none of the lag or back-and-forth hunting that plague some gearboxes.

The ride is smooth and comfortable, absorbing bumps and stable on sweeping curves. The steering has a solid on-center feel – and effective optional lane-keeping assist – for highway driving.

The RX 350 AWD’s fuel economy leads the competition. The EPA rates it 19 mpg in the city, 26 on the highway and 22 combined. The key combined figure beats all the competitors I’ve named, except the MDX and GLE, which match it.

The RX runs fine on regular gasoline, while the MDX and GLE require premium. The EPA estimates that will make the RX $350 a year less expensive to operate, based on current fuel prices.

The Lexus RX earned leadership among luxury SUVs with 17 years of sustained excellence. The comfortable and attractive 2016 model is likely to maintain that enviable status.

Still, it seems the leading luxury SUV should push the envelope in some area –  technology, design, connectivity, safety, autonomy … somewhere.