Acura TL sedan reworked for performance as well as comfort
Bob Plunkett, Sun, 28 Jun 2009 07:42:39 PDT
LAKE CITY, Ky. -- To test the sticky tire grip of a chic TL, Acura's luxury sports sedan in the expansive incarnation of 2009, we steer one down The Trace Road, Kentucky 453, which wiggles over hilly terrain in the Land Between the Lakes National Recreation Area.
Coursing over humpback hills and cutting some acute-angled corners at the bottom of deep downhill plunges, this twisty strip of asphalt seems like it was designed expressly to show off the four-wheel agility of TL as equipped with Acura's SH-AWD (Super-Handling All-Wheel-Drive) equipment.
The smart SH-AWD system can disburse the engine's considerable torque not only to wheels fore and aft but the left or right ones too. It's always engaged and enables the vehicle to maneuver on wet or dry pavement with the uncanny agility of a wily sports car.
The device goes further than AWD controls employed by other vehicles because it can automatically increase the rotation speed of an outboard rear wheel during quick and hard cornering maneuvers.
Boosting the rear wheel's rotation speed ends up decreasing the cornering load on the car's front wheels, which thwarts the tendency of an AWD system to understeer and ultimately enhances total tire grip through a turn.
It allows the TL to carve precise turns on a curlicue route like The Trace Road and run circles around some size-wise competitors. Acura's AWD system normally channels most of the engine's power to the front wheels.
At normal cruise speed, about 90 percent of the torque is driving the front wheels, while the remaining 10 percent goes to turn the rear ones. If you put your foot hard into the accelerator, however, a computer quickly inverts the power ratio. It shoots up to 70 percent of torque to rear wheels to help the acceleration effort, while still holding 30 percent on the front wheels.
And there's plenty of power at play with TL, thanks to a forceful new V6 engine aboard the SH-AWD version.
TL's new aluminum V6 displaces 3.7 liters with SOHC (single overhead camshaft), four valves for every cylinder and a drive-by-wire throttle plus VTEC (variable valve timing and lift electronic control) technology which continually adjusts phasing of the intake camshaft with changes in valve lift, timing and duration.
The plant produces 305 hp at 6200 rpm and 273 lb-ft of torque at 5000 rpm.
Standard transmission is an electronically-controlled automatic five-speed outfitted with Acura's sequential SportShift override for manual shifts via hand paddles mounted on the steering wheel.
The transmission has a unique "grade logic" shift point governor that selects top gear settings after measuring variables like throttle position, road speed and the rates of acceleration and deceleration.
Acura also builds the TL in FWD (front-wheel-drive) mode with a different V6 engine but the same five-speed automatic SportShift transmission. The TL FWD stocks a SOHC 3.5-liter VTEC V6 which nets 280 hp at 6200 rpm and 254 lb-ft of torque at 5000 rpm.
Both models -- TL and TL SH-AWD -- carry an electric power steering (EPS) system which employs a quick-ratio rack and pinion setup with speed-sensing variable assistance. Both also use an independent suspension system.
The front suspension consists of a double-wishbone design that precisely controls wheel motion. The rear suspension, in a multi-link layout, settles the rear and delivers an exceptionally smooth ride.
A big disc brake applies at every wheel, with ABS (anti-lock brake system) plus EBD (electronic brake distribution) and BA (brake assist) units, a TCS (traction control system) and VSA (vehicle stability assist) mechanism to correct lateral car skidding.
TL rolls on Bridgestone Turanza P245/50R17 rubber mounted on 17-inch cast-aluminum alloy wheels, while TL SH-AWD bumps up to Michelin Pilot HX MXM4 P245/45R18 tires with 18-inch cast-aluminum alloy wheels.
TL and TL SH-AWD of 2009 represent a fourth generation for Acura's mid-size luxury sports sedan and the largest iterations by far.
Wheelbase length for TL grows 1.8 inches longer to 109.3 inches, as the width of the front/rear wheel track expands by an inch or more. These additions in wheelbase length and track width forge a larger platform, which sets up a larger structure with more space in the passenger compartment.
The longer and wider cabin creates more legroom and elbow room for riders. Cabin layout shows a pair of form-fitting bucket seats up front and a bench for three adults in back.
Take a walk-around tour of TL and you'll discover a streamlined body posing in hunkered stance that makes it appear ready to romp.
There's a low hood line to enhance forward visibility for the driver, with projector-beam HID (high intensity discharge) headlamps on front corners of a pointed prow crowned by a pentagonal grille in silver paint.
The driver-oriented cockpit features a leather-wrapped steering wheel, an instrument cluster with light-emitting-diode (LED) back-lighting for an easy read and a Multi-Information Display (MID) which provides access to a variety of electronic functions.
Posh gear includes premium leather trimming the seats, automatic controls for the climate system with dual zones for comfort, power operation for windows and mirrors and door locks, the driver's bucket with 10-way power controls including adjustable lumbar support, heat elements inside both front buckets, a center console up front, power moonroof with tilt, auto-open/close, auto-reverse and key-off functions, a keyless entry device, and a 276-watt premium audio system with a six-disc changer, eight speakers and XM satellite radio service.
TL or TL SH-AWD may be upgraded with a Technology Package of electronic gear like a navigation system with voice recognition and rearview camera, AcuraLink real-time traffic and weather radar mapping, a 440-watt premium audio system with 12.7-gb hard disk for media storage, and a keyless access system with pushbutton ignition.
Acura establishes MSRP figures for the 2009 TL series beginning at $34,955 for TL FWD, or $38,685 with the Technology Package aboard. TL SH-AWD tallies to $38,505, or $42,235 with the Technology Package.