Saturday, October 26, 2013

2014 Acura MDX Advance SH-AWD

As much as we'd like for every car that we review to be as exciting as the Jaguar F-Type that recently graced the Car Tech garage, the reality is that most of the time I'm driving regular sedans and dull SUVs. So, while there was a lot to look forward to with the 2014 Acura MDX's arrival -- it's handsome new design, jewel-like full LED headlamps, and the promise of updated tech, for example -- the reality was that I was fully prepared to be just a bit bored this week.

And then I hit the road, curiously tapped the button for the Lane Keeping Assist system, and was met with one of the weirdest drives of my life.

Advanced, awkward, awesome
The MDX's midtier Technology package adds a number of passive driver aid technologies, such as a blind-spot-monitoring system, a forward collision warning system, and a lane departure warning system. Each of these systems will chide you with visual and audible alerts, letting you know that there's potential danger -- such as merging into a lane that's currently occupied or drifting out of your current lane because of inattentiveness -- but they don't actively intervene in any way.

However, the MDX's top-tier option package and trim level, the MDX Advance, adds active intervention abilities to the passive driver aid features of the Technology package. Forward collision alert becomes a Collision Mitigation Braking System that can automatically engage the brakes to slow the vehicle before an imminent collision, reducing the force and severity of the impact. Cruise control becomes Adaptive Cruise Control (ACC) with a low-speed follow feature that allows it to maintain a safe following distance with the leading vehicle all the way down to a complete stop and resume its speed when the lead vehicle moves. The standard rearview camera gets front and rear parking proximity sensors.

We've seen a number of these technologies before, but things get interesting when the lane departure warning becomes a Lane Keeping Assist, arguably the weirdest feature in the MDX's bag of tricks.

By processing the road ahead of the vehicle with a forward-facing camera, Lane Keeping Assist is able to discern the lane marker lines and calculate where the MDX is between them. It then is able to nudge the vehicle left or right to keep it centered in the lane. However, where other lane-keeping systems that we've tested only keep you from leaving your lane and pull this trick off with biased braking, Acura's system works to keep you centered in the lane before you get out of bounds and influences the vehicle's direction through electronic power steering. The weird bit is that you can feel all of this happening as you hold the wheel.

To get an idea of what driving with Lane Keeping Assist activated feels like right now, grab a friend and hop in your car. Once under way, have your friend put two fingers on top of the steering wheel and tell him to help you steer in tandem. Now, he's only got two fingers on the wheel and you've got two hands at 3 and 9, so you can easily overpower him and retain control of the vehicle. You'll both be looking at the same road and working toward the same goal of keeping the car from careening off of the road, so you'll stay fairly centered in your lane. However, your inputs will be just slightly out of sync. You'll be able to feel his tiny corrections, sometimes working with you and sometimes against. This is what Lane Keeping Assist feels like, and it's very off-putting at first.

2014 MDX Acura

With the aid of cameras, the MDX can keep itself centered within its lane.

(Credit: Josh Miller/CNET)

My initial reaction to Lane Keeping Assist was revulsion. I was very vocal to the other Car Tech editors about disliking the feeling that the car was fighting me to stay in the lane. However, I forced myself to drive for hours with the Assist engaged -- completing the entirety of my 120-mile loop of the San Francisco Bay Area -- and found that, after a while, I got used to it. And I noticed a few things.

First, the system didn't seem to be able to make large corrections, such as following a bend in the road or it's assistance wasn't strong enough to push far enough past my hands' neutral position to affect a large turn. It's only got enough freedom to keep you centered in the lane. I also noticed that if you let go of the steering wheel while Lane Keeping Assist is active, you can actually see the wheel move as it makes small corrections to keep the car straight for a few moments. However, once the system realizes that you're not helping, it will flash a Steering Input Required warning before deactivating assistance. Presumably, this is to keep drivers from engaging the system and taking a nap while the MDX drives from San Francisco to LA. The car can't quite drive itself, despite the fact that sometimes it feels like it wants to.

Lane Keeping Assist is a small, but awesome, step toward the self-driving car that automakers have been promising us. Though, at the end of the day, I'd rather do the driving by myself and unassisted, but I'm a bit of a control freak like that.

Engine and economy
Disable the electronic assists and you'll find that the MDX's electronic power steering is not bad at all. In fact, I was very impressed. The level of assist can be adjusted on the fly by the driver with a button on the center console labeled IDS or Integrated Dynamics System.

Tapping this button toggles between Sport, Normal, and Comfort modes. I found that, when in its Sport setting, the steering had a nice weight to it that was pleasing, with a good level of resistance to my inputs. Road feeling through the fingertips was next to nil, but I enjoyed the responsiveness. Sport was the mode that I preferred, but drivers who like effortless steering can toggle to the Normal or Comfort modes for a progressively lighter feeling.

Engine bay

Somewhere beneath the plastic shrouding is a new V-6 engine that's sometimes an I-3.

(Credit: Josh Miller/CNET)

Lift the Acura's hood and use your imagination to see beyond the sea of plastic covers and you'll find a 290-hp, 3.5-liter V-6 engine. Torque is stated at 267 pound-feet thanks to a combination of direct injection, Acura/Honda's i-VTEC variable valve timing, and lift control. This engine is down a bit in displacement and down a just few ponies, but it's also up where efficiency is concerned. Thanks to a technology called VCM or Variable Cylinder Management, the MDX's V-6 is able to shut down some of its cylinders, effectively becoming an I-3, for increased fuel economy during passages where the full capabilities of its engine aren't needed, such as when cruising on a flat highway.

Fuel economy is estimated by the EPA at 20 city, 28 highway, and 23 combined. I managed to maintain about 25 mpg during my highway-heavy test period.

The engine is transversely mounted -- hinting at its front-wheel driven roots -- and is mated to a six-speed automatic transmission that features normal, sport, and manual "SportShift" modes. Sport mode actually adds a bit of engagement to the drive, holding the revs higher in the range before shifting to better access available power. However, the manual shift mode, controlled by steering-wheel-mounted paddle shifters, isn't particularly sporty thanks to a noticeable lag between slapping a paddle and the resulting shift.

Rear wheels

SH-AWD can shift as much as 70 percent of torque to the outside rear wheel to aid in cornering.

(Credit: Josh Miller/CNET)

The MDX's platform may be a front-driver, but our example was equipped with Acura's optional Super Handling All-Wheel Drive (SH-AWD) system, which can send as much as 70 percent of available torque to the rear wheels when extra grip is needed or as little as 10 percent when cruising. The "Super Handling" portion of SH-AWD comes into play when cornering when rear axle torque vectoring can shuffle torque between the two rear wheels, sending power to the outside rear wheel to help rotate the vehicle when accelerating out of a corner. You can watch all of this torque shifting and shuffling between the four wheels on an LCD in the MDX's instrument cluster.

Share This!


1 comment:

Powered By Blogger · Designed By Tech News