When many people think of Buick, LaCrosse is the image that comes to mind.

It’s a big, comfortable, quiet, full-size sedan. The 2017 LaCrosse has been redesigned to make it lighter, lower and wider — and in the process Buick certainly hopes it will be viewed as more youthful.

But in the end, it remains the quintessential Buick, a car that likely will score with older buyers who see it as a reward for a life well-lived, saving the smaller models and SUVs for the younger image that the brand portrays in advertising.

Modernizing the flagship LaCrosse couldn’t come at a better time for Buick. The General Motors brand has been scoring points lately, both in the design of its concept cars and in its build quality. Consumer Reports recently named Buick as the first domestic brand to reach the top three, behind Lexus and Toyota, in its annual list of reliability.

As the flagship, LaCrosse is, by its very nature, substantial. Buick has done its best to slim it down by 300 pounds in the name of better fuel economy, which is no easy feat.

But it was necessary since LaCrosse must compete against a highly competitive field that includes cars like Ford Taurus, Chrysler 300, Nissan Maxima, Toyota Avalon and Hyundai Azera, to name a few. Adding to the pressure, car sales overall are down. LaCrosse sales were down 37.1% for the first 10 months of this year compared with the same period last year, Autodata reports, although that kind of drop is not unusual when a new version is in the wings.

Against its competitors, LaCrosse holds its own. LaCrosse puts the premium on how smoothly it drives and the quietness of its cabin. Where we noticed — and appreciated — the silence most was the stop-start function, common in cars now as a way of saving gas. We barely noticed when the car’s engine turned off at stop lights or signs, then restarted when we pressed the gas pedal. That’s a welcome change from the jarring experience in some cars.

Some of the credit goes to LaCrosse’s 3.6-liter V-6 engine, which works in tandem with an eight-speed automatic transmission. The 305 horsepower it provided were plenty, though not an overabundance. What impressed us more was the fuel economy. We achieved 30 miles a gallon over 327 miles of mostly freeway driving, at the high end of the car’s EPA rating of 21 mpg in city driving and 31 mpg on on the highway. After the weight reduction, gas mileage was boosted 3 mpg over the outgoing 2016 model.

And in the premium version that we tested, there was no overlooking the plush touches expected of a Buick. Our model had the optional rear sunshade, part of the $1,550 power sunroof package. It also has a massage unit built into the seat, nice once you get used to the idea of mechanical fingers working on your lower back as you glide down the interstate.

One more thing about that seat. It had GM’s butt-thumping proximity alert system. So, for instance, if you get too close to another car or wall as you back up, your rear end gets thumped by the seat before the message can travel to your brain. We find it somewhat disconcerting, but at least it’s less distracting to passengers in the car than a beep or some other audible warning.

All told, between the options and the higher trim level, the model we tested came in at $47,370, including the $925 delivery charge, a big leap from LaCrosse’s base price of $33,915.

It’s a reasonable price given LaCrosse’s improvements and the competition. But we urge prospective LaCrosse buyers to cross-shop it against corporate stablemate Chevrolet’s Impala, which has some of the same features and sharp looks to go with them.

What Stands Out

Redesign: Fresh looks help a lot

Quiet: Barely noticed the stop-start

Fuel economy: 30 mpg as tested in a big car. Wow!

2017 Buick LaCrosse

What? A big, plush full-size car

When? On sale now

Where? Made in Detroit

How big? 16.4 feet long

What makes it go? A 3.6-liter V-6 with an eight-speed automatic transmission

How much? $33,915, including $925 in shipping, to start.

Overall: A solid choice in a crowded field

Y