Infiniti M56: Nipped, tucked and powered up

This may come as a bit of shock to you, but we like our makeovers here in L.A.

We give them to sweater-clad canines, pasodoble-dancing septuagenarians and babies. The only things more common than plastic surgeons’ offices are marijuana dispensaries and yoga huts. And if you look carefully, I’m sure you could find a place offering all three.

So there is a bit of circumstantial congruity to driving the new Infiniti M56 in and around L.A. It’s a made-over car in a made-over town.

It’s a good bet you’re scratching your head trying to recall Infiniti’s M line, which was part of the problem. The only thing memorable about the previous mid-size version was its unabashed rear end — and that’s not a compliment. In this ravenously competitive segment, which features perennial titans like BMW’s 5-series, Mercedes-Benz’s E-class and Audi’s A6, Infiniti’s previous M was like an overlooked Jell-O mold in the dessert buffet at the Bellagio.

There was work to be done.

For starters, Infiniti nipped, tucked and augmented the M’s exterior into a tasty, not-so-little dish. The look is aggressive and shapely at the front and much more tidy in the rear than the outgoing model. It’s now clearly an Infiniti and follows design language found throughout the lineup. The highlight of the car’s newfound figure is the curvaceous hood that clings to the engine like that silk Valentino dress you spent too much on, before flaring skyward to give a similar embrace to the wheel arches, themselves the custodians of optional 20-inch wheels. Such romantic treatment of an otherwise innocuous part of the car is too rare these days.

Lurking beneath this folded metal is one of two new engines, each apropos of its environment and each a significant bump in power over its predecessor. The M37 line features a 3.7-liter V-6 good for 330 horsepower (up from 303 hp) and 270 pound-feet of torque, while the M56s get a burly 5.6-liter V-8, which produces 420 hp (up from 325) and 417 pound-feet of torque. Gas mileage is estimated at 18/26 for the V-6 (city/highway) and 16/25 for the V-8. Each is paired with a seven-speed automatic transmission with a manual shift mode, though column-mounted paddle-shifters are available only as part of the $3,600 Sport package.

Nissan, Infiniti’s parent, declined to provide acceleration stats. But Car and Driver magazine clocked the M56 at 4.7 seconds going from zero to 60, 5.6 seconds for the M37.

The interior also saw the business end of a makeover artist’s bag of tricks. Infiniti varnished the center stack controls with a coat of logic, as many of the buttons for the navigation, climate and radio are where they should be, though it could use another coat in some places to extricate a few leftover buttons. Fit and finish are on par with ze Germans. Highlights include one of the best navigation systems in the industry and an optional Bose sound system better than the one in your living room.

Also optional on both models is a system that monitors your blind spots using tiny cameras in the windshield to detect cars in the lanes next to you. It illuminates a small light in the corner of both windows by the side-view mirrors when a vehicle is in your blind spot. Should you go to change into the occupied lane, the light will blink and the system will beep; ignore that and the system gently applies so-called selective braking to the appropriate wheels to help bring you back into your lane. This feature can also be used to keep you in your current lane, regardless of traffic.

Does the whole thing work? Sort of. The lights and the beeps (the volume of which is adjustable) straddle the fine line between useful and annoying. The braking feature is helpful in pulling you back into your lane should you drift out. But the limits of this technology render it unable to react quickly enough and forcefully enough to prevent you from plowing into the car next to you. So for now, your mother-in-law is still the better bet.

Blind-spot watching aside, the M is a solid performer on the road. In a straight line, the V-8 wastes no time introducing you to your seatback. It’s loud enough to remind you of its cylinder count but civilized enough to pacify the delicate sensibilities of the clients you’re taking to lunch. When your course points you toward the bends and apexes, the chassis of the M reveals itself to be poised and confident, though there is some understeer wafting about, especially when pushing the car to its limits with the traction control off.

A standard feature on all Ms is what Infiniti calls the Drive Mode Selector. It’s a switch in front of the armrest that allows drivers to choose among four settings, Snow, Eco, Standard and Sport. Each setting adjusts the throttle and transmission (and consequently gas mileage) depending on the driver’s choice.

Standard mode is well suited to most driving you’ll do, from mundane chores around town to highway driving with the family. Eco mode seems silly in a car with a 420-hp V-8, and turning it on in effect makes you the proud owner of the largest, slowest golf cart this side of Palm Beach.

For a good time, ignore that number on the bathroom stall, turn the switch to Sport and turn off the traction control. Mix in one part twisty road and one part manual shifting, and you can really have some wheel-spinning, grin-inducing, neighbor-complaining fun. Just watch out for that understeer.

As far as makeovers go, this does indeed have a Hollywood ending. Infiniti finally has an actual competitor in this segment, rather than a pretender. At this point it comes down to personal taste and brand loyalty. But at least no one is settling for Jell-O.

david.undercoffler@latimes.com