|The 2011 Ford Explorer SUV. Click to enlarge.|
Ford has introduced the new 2011 Explorer. Offering two new engines—a new 3.5L V6 and the new 2.0L I4 EcoBoost (earlier post)—the new Explorer offers up to a 30% improvement in fuel economy over the current Explorer. The 2010 Ford Explorer 2WD with a 4.0L V6 is EPA-rated at 14 mpg US city, 20 mpg US highway and 16 mpg US (14.7 L/100km) combined.
3.5L Ti-VCT. The Explorer 3.5-liter V6 is offered as standard equipment across base, XLT and Limited models and delivers an anticipated improvement in fuel economy of more than 20% versus the current Explorer. Using Ti-VCT (Twin Independent Variable Camshaft Timing, earlier post) for optimized fuel economy and reduced part-throttle emissions, this engine delivers an estimated 290 hp (216 kW) and 255 lb-ft (346 N·m) of torque.
Mechanical efficiency, performance and fuel economy have been improved through Ti-VCT, a low-tension drive belt featuring a one-way clutch for the alternator, a direct-acting mechanical bucket (DAMB) valvetrain with polished buckets to reduce friction, piston-cooling jets, improved bay-to-bay breathing through the cylinder block and composite cam covers that reduce engine weight.
Ti-VCT allows precise, variable control of valve overlap, or the time when intake and exhaust valves are open concurrently. This enables increased mechanical efficiency for improved response and performance, while optimizing fuel economy. In part-throttle conditions, Ti-VCT helps reduce emissions.
The 3.5-liter V6 also features improved deceleration fuel shutoff technology to maximize fuel economy in closed-throttle situations.
The Explorer V6 has been engineered for durability with a chain-driven camshaft, high-strength forged powder metal connecting rods with floating pins, fully counterweighted forged steel crankshaft, a die-cast aluminum deep-sump oil pan and four-bolt main bearing caps with side bolts through the engine block.
Noise, vibration and harshness (NVH) characteristics are controlled and reduced through a tuned composite upper and lower manifold, the silent-chain cam drive and an acoustic engine cover.
The Explorer 3.5-liter V6 offers power to tow up to 5,000 pounds when properly equipped.EcoBoost 2.0-liter I-4. Combining direct injection of gasoline and turbocharging, the EcoBoost2.0-liter I-4 delivers performance comparable to normally aspirated competitive V6 engines. Developing up to 237 hp (177 kW) at 5,500 rpm, this I-4 delivers 250 lb-ft (339 N·m) of torque.
Estimated fuel economy improves by more than 30%, putting the fuel efficiency of the Ford Explorer in line with sedans such as the 2010 Toyota Camry V6.
As in other Ford EcoBoost engines, peak torque is generated at a low 1,700 rpm across a broad band to 4,000 rpm. This torque plateau makes for flexible, efficient power delivery across a wide range of engine and vehicle speeds, while helping save fuel by making power at lower rpm levels. Ti-VCT, four valves per cylinder and DAMB valve lifters increase mechanical efficiency through improved engine breathing across the broad power and torque bands.
A relatively high compression ratio is enabled by the use of direct gasoline injection, operating at fuel pressures from 2,200 to 2,800 psi. The unique turbocharger is optimally matched to the EcoBoost I-4 engine and SUV vehicle performance behavior. Precise fuel pressure control allows the Explorer I-4 to deliver boosted power at low rpm, without annoying turbo lag.
The EcoBoost I-4 uses 5W30-GF4 oil to reduce friction and reduce cost of ownership through 10,000-mile oil change intervals.
Targeted durability is 10 years, or 150,000 miles. Durability actions include enhanced oil filtration and cleanliness, the addition of an aluminum oil cooler with improved heat dissipation and cast inter-bore cooling inside the aluminum engine block. This engine represents the initial US-market application of the brick-style charge-air cooler, delivering increased thermal efficiency.
The new 2.0-liter EcoBoost engine is being introduced globally by Ford Motor Company, with applications in various products in Europe, Asia and Australia, in addition to the new Explorer.
Each Explorer engine is paired with a unique six-speed automatic transmission, combining lowered initial gears for improved off-the-line acceleration and higher gearing for improved efficiency at lower engine rpm when cruising.
Weight reduction is also a key element in improving Explorer fuel efficiency. While adding significant content to the vehicle, engineers were able to reduce total vehicle weight by almost 100 pounds through the use of lighter materials such as an aluminum hood.
Explorer’s EPAS system allows for variable rates of assistance based on speed, turn-in and direction. In addition to optimized steering feel, tight on-centering and appropriate resistance, EPAS provides a fuel economy benefit in comparison to traditional hydraulic power assist systems. EPAS also enables a competitive turning radius for optimum maneuverability in parking situations, combined with increased assistance at low speeds for parking ease.