Infiniti Q50 vs. Lexus IS 250: An upscale face-off

Infiniti vs. Lexus is the Japanese luxury auto equivalent of the Hatfields vs. McCoys—or perhaps Chevy vs. Ford, with higher price tags. Both marques rolled into the market in 1989 and have gone head-to-head ever since.

So, on paper, the sports-sedan showdown between the redesigned Infiniti Q50 and Lexus IS 250 promised to generate some real spark. But in our testing, neither model lived up to expectations, and both ended up anchored at the bottom of our upscale-sedans category.

Most perplexing, however, is that the class leader—by a sizeable margin—is still the Infiniti G37, which the Q50 was designed to replace. What happened?

The G has been one of our highest-rated sedans for some time, earning a coveted spot in our annual Top Picks list for six of the last seven years. It delivers an inviting blend of sportiness, luxury, and comfort. But after its 2014 redesign and transition to Infiniti's new Q designation, this car seems to have lost its way.

With mundane handling, due in part to its dull steering, the Q50 isn't as much fun to drive as the G37. And, despite aiming for a more luxurious persona, it doesn't match the G's ride comfort or easy-to-use controls. Yes, the Q50 is quick and relatively roomy. But, overall, it doesn't measure up to the higher-rated models in this class.

Still, the Q50 is much better than the IS 250, which is neither sporty nor luxurious. Its acceleration lacks punch, handling is lackluster and short on finesse, the cabin is cramped and not particularly quiet or well finished, and the ride is neither plush nor tied-down.

The good news? The Infiniti G37 will remain on sale for the near future, at a lower price than the Q50, but in limited numbers. And there are several other models in this class that are better choices than either the Q50 or the IS 250.

We tested both models with all-wheel drive because we've found most buyers choose it over rear-wheel drive in today's upscale and luxury sedans. In fact, it can be hard to find two-wheel-drive versions in many regions of the country. To reflect this preference, when a sedan offers rear- or all-wheel drive, we will buy the AWD version. So equipped, our Q50 and IS 250 cost $44,855 and $43,823, respectively.

Borrowing a naming cue from Audi, Infiniti is phasing out the top-notch Infiniti G37 in favor of a model called the Q50. But, unfortunately, the 2014 iteration has taken a step back from its excellent predecessor.

The Q50 is quick and relatively roomy, but its underwhelming driving experience strips the car of much of its sporty legacy. The Q is fairly nimble, with good turn-in response and well-contained body lean. But it's let down by vague steering. Overall, the Q50 was less capable while negotiating our handling course, and it has lost the fun-to-drive agility that was a G37 hallmark.

We also tried the much hyped dynamic active steering option, but we found that it feels artificial.

The potent 328-hp, 3.7-liter V6 engine delivers very quick acceleration, but it lacks the refinement of the V6s in some competitive models. And its 21 mpg overall is nothing special for this class; the larger Audi A6 gets 22 mpg. A more fuel-efficient hybrid version of the Q50 is also available.

Most Q50s sold in snow country come with all-wheel drive, which provides added traction over the standard rear-wheel drive.

With the redesign, Infiniti intended to steer the Q50 more toward the luxury end of the sports-sedan equation. But that result isn't very convincing, either.

The ride is a bit unsettled and stiff, due partly to the car's run-flat tires, with their rigid sidewalls. The front seats aren't particularly supportive or as comfortable as we expect in a luxury sedan. In addition, cabin quietness and interior fit and finish fall short for this category. The rear seat is fairly hospitable, but the trunk is too shallow and has a small opening.

Infiniti's new dual-screen InTouch control system misses the mark, as well. The touch screen responds agonizingly slowly and can be unintuitive to use.

After starting the car, for example, you can't change radio stations until the system slowly loads. Likewise, the system struggles to catch up after several voice commands in a row. Early buyers should expect frequent software updates as Infiniti works to debug this system.

We'll hold off on recommending the Q50 until we get reliability data from owners.

Best version to get. We'd get a Q50 Premium, which starts at $39,550 with rear-wheel drive or $41,350 with AWD. The base 3.7 version is well equipped, including Bluetooth and a backup camera. But it's missing such common features as leather upholstery, heated seats, and Homelink compatibility for your garage door opener. Most cars on dealers' lots are likely to have the navigation and leather packages, which tack on another $2,400.

Beyond that, getting such expected features as seat memory, folding rear seats, or blind- spot warning requires buying big-ticket options packages, which can drive the car's price up toward $50,000. And we don't think this car is worth that much.

The 2014 IS is Lexus' latest attempt to design a BMW 3 Series fighter, which has long been considered the benchmark for upscale sports sedans. But, alas, the IS 250 isn't very sporty, fun to drive, or luxurious. Add in a cramped interior and mediocre fuel economy, and the IS ends up with a road-test score of only 52, which is too low for us to recommend it.

The IS 250's high points include eye-catching styling and a silky smooth 2.5-liter V6 that's quiet and refined, especially when compared with the turbocharged four-cylinder engines in many competing models. But its performance is rather pokey, and its 21 mpg overall is comparable to a midsized SUV.

Handling is nothing special. Body roll is fairly well contained, but the car isn't particularly agile. The steering is appropriately weighted, but it feels vague and doesn't telegraph much feedback. When pushed to its handling limits at our track, the IS was secure and forgiving, but overly pronounced understeer diluted the handling finesse and enjoyment that drivers expect from a sports sedan.

Moreover, the car's ride comfort doesn't compensate for the its lack of agility; it's neither plush nor tied down.

You'll also be disappointed if you expect the quietness of a typical Lexus interior. The road noise penetrating into the cabin creates a din that's not befitting a $40,000-plus car.

The interior is very tight, even by the modest standards of this class. The narrow cabin, wide center console, and large overhanging dashboard caused many of our drivers to feel cramped and closed-in. Making matters worse is a lump on the floor protruding into the driver's space on all-wheel-drive versions.

Other gripes: In-cabin storage is inadequate. Simply getting in and out is an ungraceful chore. And rear-seat passengers must put up with very tight confines. Fit and finish is decent, but it's not up to today's top-flight standards.

The IS controls now include the fussy, distracting mouse-like controller found in other Lexus models. You select items in the display by moving the controller, but it's easy to overshoot your intended target.

This redesigned model is too new for us to have reliability data, but historically, most Lexus models have been very reliable.

Best version to get. We bought the IS 250, which accounts for about 80 percent of IS purchases. But if you want quicker acceleration, get the IS 350. With more than 100 additional horsepower and an excellent eight-speed automatic transmission, its powertrain is much more satisfying. Still, it isn't a sporty handler, and it suffers from the same cramped packaging and other demerits of the 250. We suggest buyers get the optional backup camera ($350) and blind-spot warning system ($600), which are available individually or as part of option packages.