TEXARKANA, Tex. -- On a sprawling Texas cattle ranch where recent rains have turned our route through the cow pins into spongy sod with squishy patches of tire-sucking mud, we're trucking at a slow-go pace but pulling serious torque from a 6-pack engine to turn every nubby all-terrain tire on Toyota's mid-size 4Runner sport utility vehicle in new TRD Pro grade trim.
The TRD (Toyota Racing Development) Pro kit for 4Runner transforms an already-capable 4-wheel-drive SUV into an off-road mud-sand-rock trail champion. The dirt-dog equipment list includes TRD-tuned front suspension springs to boost the ride height, TRD Bilstein high-performance dampers with rear remote reservoirs, 31.5-inch-tall Nitto Terra Grappler 265/70R17 tires capping 17-inch black TRD alloy wheels, a TRD stamped aluminum front skid plate, color-keyed front and rear bumpers, over-fenders, side rocker panels, hood scoop and rear spoiler, plus silver-painted roof rails.
Cabin additions for the TRD Pro grade range from SofTex seat upholstery in black with red accent stitching to 8-way power controls for the driver's seat and 4-way power for the front passenger seat, heat elements for both front buckets and the Toyota Entune Audio Plus kit with Navigation.
TRD Pro edition becomes the top model for 4Runner 2016. In all, Toyota builds the 4Runner in six grades with choices of rear-wheel 2-wheel-drive (2WD) or 4-wheel-drive (4WD) traction: Entry-level SR5 2WD and 4WD, upscale SR5 Premium 2WD and 4WD, off-road Trail 4WD and Trail Premium 4WD, cushy Limited 2WD and 4WD, and TRD Pro 4WD.
The 2016 MSRP list begins at $33,810 for 4Runner SR5 2WD and climbs to $41,850 for 4Runner TRD Pro 4WD.
All 4Runner issues stock Toyota's dual-cam 4.0-liter aluminum-block V6 engine with VVT-i (variable valve timing with intelligence) to optimize torque across the engine's operating range. The plant links to a 5-speed automatic ECT-i (electronically controlled transmission with intelligence) and produces 270 hp at 5600 rpm plus torque of 278 lb-ft at 4400 rpm. Fuel-burn estimates by the EPA tally to 17/22 mpg city/highway for 2WD and 17/21 mpg city/highway for 4WD.
4Runner 2016 models amount to fifth-generation versions which remain true to 4Runner's origins in 1985: It's a truck-tough vehicle designed for serious work on dirt or pavement. Like a truck, 4Runner is built on a body-on-frame chassis. The current ladder format has boxed rails extending for the length of the platform and nine cross members to maximize torsional rigidity.
4Runner's suspension system consists of the independent double wishbone design up front with coil springs over gas shocks and a solid axle in back set in 4-link scheme also with springs on shocks.
4Runner in 2WD format stocks an automatic LSD (limited slip differential) tied to a sophisticated traction control system (TRAC) to manage the grip of both rear wheels on slippery surfaces.
The 4WD editions also carry electronic 4-wheel traction control, labeled A-TRAC (active traction control). The system can distribute driving force to any one wheel in contact with the ground.
The 4WD SR5, Trail and TRD Pro editions employ a lever-operated 2-speed part-time 4WD mechanism with neutral position, while on the 4WD Limited there's a full-time 4WD system with Torsen limited-slip locking center differential controlled with a 3-mode switch set on the center console.
4Runner Trail and TRD Pro grades add Toyota's Kinetic Dynamic Suspension System (KDSS) which disconnects stabilizer bars to allow for more vertical travel of the axle and better suspension articulation when rolling over dicey terrain.
Toyota's Crawl Control (CRAWL) device -- standard on Trail and TRD Pro -- is an electro-mechanical system that works with the transfer case set in low range regulating engine speed and output as well as brakes to send the vehicle forward or backward at a low speed. It incorporates downhill assist control (DAC), which aids in a steep descent without driver intervention.
Further, a Multi-Terrain Select system allows the driver to dial in the amount of wheel slip permitted to match the terrain.
The passenger cabin in 4Runner uses fabric seats for SR5, water-resistant SofTex seat material for Trail and TRD Pro grades and plush leather in Limited. A second-row bench divides 40/20/40 and seatbacks fold flat. Optional third-row seats split 50/50 and fold flat with 1-touch levers.