If you’re old enough to remember the energy policies of the Carter administration, green enough to have donated to the Nature Conservancy and young enough to get a rush of testosterone from dusting that polo shirt-wearing jerk in his BMW, Nissan has the car for you.

And though its styling walks a fine line between “grandpa’s luxury sedan” and “soccer mom sports car,” the 2012 Infiniti M Hybrid pulls off this delicate balancing act with grace.

The result isn’t superb on looks. As you’d expect, meeting so many different design goals results in a car that looks a little, well, melted-together. It’s not going to make anyone’s heart race on the inside, either, with slightly old-fashioned styling exemplified by the quaint analog clock in the dash.

But it is one fun ride.

The sedan’s seats ease into position when you press the ignition button, cradling your butt cheeks (and optionally warming them). The low seats and slightly bulging hood give it a sportier feel on the inside than its looks let on. The car silently backs out of its parking space on electric power alone, while a rear-view camera gives you a clear look at what’s behind you and where the car is tracking. The sound system pumps out your favorite tunes from your iPhone, which you’ve plugged into a USB port in the center console. And when you stomp on the accelerator, the 360 horsepower gas- and-electric power plant presses you back into the leather seats like nobody’s business.

Under the hood, there’s a hybrid engine similar to what’s inside the Toyota Prius: An electric motor drives the car at lower speeds and short distances until the battery is depleted to a certain level, then a bigger gasoline engine takes over.

You can choose between three driving modes with a simple dial: An eco mode saves gas, a sport mode emphasizes performance, and the “why bother” mode is somewhere in the middle.

Handling is excellent for a car that weighs more than 4,000 pounds. It hurls itself forward, into the passing lane and around corners with ease, especially in sport mode.

For all its conservative styling, there are nice, tech-y touches throughout the M Hybrid, at least with the options our test vehicle had. Blind spot indicator lights on the right and left front window pillars light up to alert you when a car is sneaking up next to you. (You’ll need those lights, too, since the rear quarter windows are tiny portholes.) The touch-screen dashboard display provides a wealth of data (fuel economy, maps, what’s on your iPod) without getting over-cluttered. And it’s got a respectable sound system.

And did I mention it’s comfy?

In short, everything about the M Hybrid is smoooooooth. Even at 100mph, you feel like you’re sitting in your grandpa’s living room, eating hard candies as you watch that BMW disappear in your rear-view mirror.

Not bad for a relatively economical hybrid.

WIRED Sporty performance reminds you that you’re still alive. Comfortable interior keeps your body cradled in soft, warm leather. Console can control playback of music on an iPhone, iPod or thumb drive plugged into the USB port. Blind-spot indicator lights quickly become an indispensable safety feature. Fun to throw around on twisty country roads. Fuel economy averaged 24.5 mpg over a week of mixed driving.

TIRED Fronts seats are individually heated, but don’t actually massage your back. Rear-view camera easily obscured by raindrops. Poor rear visibility. If you don’t have at least a few gray hairs, you’ll probably feel awkward in such a grown-up-looking vehicle.

Photos by Jim Merithew/Wired