Honda’s 2015 model-year CR-V will include the option of a new diesel engine and 9-speed automatic transmission that deliver, the OEM claims, one of the best power-to-consumption ratios of any engine currently on sale.
The CR-V’s diesel line-up, expected to account for more than 60% of sales, has been enhanced with the addition of the all-new 160ps 1.6-liter i-DTEC four-cylinder unit from Honda’s Earth Dreams Technology series, first introduced in 2013 as a 1.6-liter i-DTEC with 120ps.
The engine, which is unique to Europe, replaces the 2.2-liter i-DTEC diesel unit. Aided by a new two-stage turbo, it offers higher power output and better power delivery, as well as superior levels of efficiency and significantly reduced CO2 emissions. As a result, the new engine has the best power-to-consumption ratio available in its segment.
A number of innovations reduce frictional energy losses, with the engine friction of the i-DTEC engine now 37% lower than its predecessor and equivalent to that of a petrol unit. The result is a fuel economy of 4.9l/100km (combined cycle).
The engine produces a maximum power of 160ps (a 6% increase over the 2.2-liter diesel predecessor) and 350Nm of torque, while emitting 129g/km of CO2 (an 11% improvement and a figure not bettered by any similarly-powered competitor, according to Honda) when mated to the 6-speed manual transmission.
The two-stage turbo uses two units, one located upstream and one downstream from the exhaust gas flow. The upstream turbo (facing a higher exhaust pressure) is called the high-pressure turbo, while the downstream unit (facing a lower exhaust pressure) is called the low-pressure turbo. The high-pressure turbo is responsible for air flow to the engine at low engine speeds, while the low-pressure turbo operates at high engine speeds. At mid-range engine speeds, both turbos work in tandem to provide charge air to the engine. The smaller, high-pressure turbo is controlled by a variable geometry turbine (VGT) to ensure quick throttle response and reduce pumping losses at low engine speeds. The low-pressure turbo is controlled by a conventional waste gate valve.
The 1.6i-DTEC diesel engine complies with Euro6b emission regulation, meeting emission standards using a NOx storage catalyst (NSC) after-treatment system, continuously alternating NOx adsorption and conversion (reduction) processes.
The focus of development was to enable a light-off of the catalyst at low temperatures, in order to sufficiently convert NOx emissions while maintaining conversion efficiency at high temperatures. This has been achieved via optimization of the ratio of precious metal amount and effective adsorption surface.
The 2015 CR-V will be available with a newly-developed 9-speed automatic transmission, which replaces the previous 5-speed automatic. The new gearbox offers a number of real-world benefits to European consumers. With a wider spread of gears, the very low first gear ratio ensures a quick and powerful launch, while a high top gear ratio results in reduced engine speed, reducing fuel consumption and noise levels at cruising speeds.
With a greater number of gears and smaller gear steps, it also provides better response to driver inputs, and smoother shifts giving the sensation of more linear and harmonic acceleration through the gears.
Depending on engine speed and throttle application, the new 9-speed automatic transmission can even shift directly from 9th to 5th gear, and 7th to 4th gear, in addition to all two-gear and one-gear downshifts. All other multiple downshifts are overlapped where an additional shift needs to be performed in the background in order to achieve the target gear.
The efficient packaging of the new transmission results in a smaller, 35kg-lighter unit, enabling better weight distribution across the vehicle. The new engine and transmission together weigh 65kg less than the previous equivalent powertrain combination, benefitting ride, handling and steering response, as well as efficiency.
