Camry in Europe features new 2.0L engine with VVT-iW for both Atkinson and Otto cycles; 13% lower fuel consumption
The 2014 Camry in Europe is benefitting from a new, Euro V-compliant, 4-cylinder, 1,998 cc, 16v, DOHC petrol engine mated to a 6-speed Multi-mode automatic transmission which replaces the existing 2.0-liter unit and its 4-speed automatic transmission.
With a high 12.8:1 compression ratio, the new engine generates maximum power of 150 DIN hp/110 kW at 5,600 - 6,500 rpm, and maximum torque of 199 N·m (147 lb-ft) at 4,600 rpm. This accelerates the Camry from 0-100 km/h in 10.4 seconds, and on to a top speed of 210 km/h (130 mph). At 7.2 l/100 km (32.7 mpg US), fuel consumption is a substantial 13% less than that of the outgoing engine.
Several advanced technologies have been adopted to achieve these values, including a new Variable Valve Timing-intelligent Wide (VVT-iW) system. VVT-iW was first introduced in 2013 on the Lexus NX 200t with the direct-injected 2.0L turbo 8AR-FTS engine. (Earlier post.) The Lexus RC F also features an Atkinson-Otto combination. (Earlier post.)
VVT-iW features standard VVT-i on the exhaust valves and VVT-iW on the intake side. The latter features a mid-position camshaft lock mechanism which retards the continuously variable valve timing.
This allows the engine to run in the Atkinson cycle at low revs for improved fuel economy and lower emissions, and in the Otto cycle at higher engine speeds for enhanced power delivery and performance, while delivering high torque output throughout the rev band.
The concept of combining the Atkinson cycle at part loads with the Otto cycle at full loads stretches back more than 30 years to a 1982 paper by a team of researchers from Tel-Aviv University and the Israel Institute of Technology. (Earlier post.)
With its expansion stroke longer than its compression stroke, the Atkinson cycle can achieve a higher thermal efficiency than its Otto counterpart. The Atkinson cycle with the high compression ratio is a common approach that hybrid vehicle engines—with unconventional valve timing to produce the effect of a shorter compression/longer expansion stroke—use to enhance thermal efficiency. However, the drawback is a reduction of engine torque; in a hybrid, the motor torque compensates for this reduction in engine torque. The availability of the Otto cycle in the combined-cycle engine also addresses this.
(Toyota engineers have also developed an approach to applying the Atkinson cycle for engines in conventional, non-hybrid vehicles. They presented their work—embodied in the new 1.3-liter ESTEC (Economy with Superior Thermal Efficient Combustion) engine—in papers this spring at the SAE 2014 World Congress, the Vienna Motor Symposium, and the JSAE Annual Congress. Earlier post.)
The new 2.0 liter unit in the Camry also benefits from Toyota’s D-4S fuel injection system. With separate twin injectors for both direct and port injection, D-4S performs both high-pressure direct injection into the cylinder and conventional intake port injection, or direct cylinder injection only, in accordance with engine speed. Hence, intake air and fuel are mixed evenly at all engine speed ranges, increasing throttle response, power and torque over a wide range of engine speeds without sacrificing fuel efficiency and environmental performance.
In addition, the unit is equipped with a water-cooled Exhaust Gas Recirculation (EGR) system. This system combines a highly-efficient EGR cooler with a highly-responsive, electronically-controlled EGR valve to give optimum control of the EGR gas flow volume for equal distribution to each cylinder, enhancing fuel economy.
Numerous additional measures have been adopted to further improve both engine performance and fuel economy.
The shapes of the cylinder head intake port and piston have been optimized, creating tumble flow inside the cylinder for enhanced combustion. Improved cylinder block and head cooling, piston oil jet cooling and an optimized taper squish shape improve anti-knock performance, realizing a high compression ratio of 12.8:1.
An offset crankshaft reduces the piston thrust load to lower friction losses. Allied to enhanced cylinder bore roundness, a resin coating to the piston skirts and lower tension piston rings reduce friction losses from the rotating parts. And the adoption of roller rocker arms and a low friction timing chain further reduce valvetrain friction losses.
The new 6-speed intelligent Electronically Controlled Transmissions (ECT) feature Flex Lock-up Control, Artificial Intelligence (AI)-SHIFT Control, an Automatic Transmission Fluid (ATF), and an Eco Driving indicator. In combination, these features offer smooth shifting and low noise with excellent performance and fuel economy.
Other engine offerings on the Camry in Europe are:
2.5L 4-cylinder gasoline engine. The 4-cylinder, 2,494 cc, 16 valve DOHC petrol engine generates 133 kW/181 DIN hp at 6,000 rpm and a maximum 231 N·m (170 lb-ft) of torque at 4,100 rpm. It will accelerate the Camry from 0-100 km/h in 9.0 seconds, and on to a top speed of 210 km/h (130 mph). The 2.5-liter unit offers fuel consumption of 7.8 l/100 km (30 mpg US).
Numerous features boost engine performance, maximize fuel efficiency and lower emissions. These include a highly-efficient intake port; an improved, variable intake manifold Acoustic Control Induction System (ACIS); a Tumble Control Valves (TCV) system; Dual VVT-i for both intake and exhaust camshafts; the adoption of roller rocker arms; low tension piston rings; multi-point oil jets and a variable output oil pump.
3.5L V6 gasoline engine. Also benefiting from performance and fuel efficiency enhancing features such as ACIS and Dual VVT-i, the Euro V-compliant, 3,456 cc V6 petrol engine generates 204 kW/ 250 DIN hp at 6,200 rpm and a maximum 346 N·m (255 lb-ft) of torque at 4,700 rpm. The unit produces a 0-100 km/h acceleration time of 7.1 seconds, and maximum speed is 230 km/h. Conversely, fuel consumption is just 9.3 l/100 km (25.3 mpg US).