Toyota introduces new diesel engine with thermal insulation coating
19 June 2015
Toyota announced a newly developed direct-injection turbo diesel engine featuring the “world's first” use of Thermo Swing Wall Insulation Technology (TSWIN). The thermal barrier technology helps the 2.8-liter 1GD-FTV engine achieve a maximum thermal efficiency of 44%, according to the manufacturer. Despite smaller engine displacement in comparison to the current KD engine, the maximum torque is improved by 25%, the low speed torque is improved by 11%, and fuel efficiency has improved by 15%.
The same engine lineup includes the 2GD-FTV 2.4-liter direct-injection turbo diesel engine. The Japanese and European market versions of the engines also have Toyota’s first-ever urea SCR system that can eliminate up to 99% of NOx emissions.
The newly developed 1GD-FTV is currently available in the new Hilux small pickup truck launched in Thailand in May 2015, and in the partially redesigned Land Cruiser Prado launched in Japan on June 17. The engine will be also used in vehicles for other markets—including Asia, Middle East, South America, Australia and Russia—but apparently it is not intended for the North American market.
The new 1GD-FTV engine has a displacement of 2,754 cc, a compression ratio of 15.6 and a maximum output of 130 kW (177 hp). The maximum torque is 450 Nm at 1,600 - 2,400 rpm, while the low speed torque is 370 Nm at 1,200 rpm. The 2GD-FTV is a smaller engine, with 2,393 cc, 11o kW (150 hp) and 400 Nm of maximum torque.
Thanks to the TSWIN insulation technology and the use of silica-reinforced porous anodized aluminum (SiRPA) on the pistons, the cooling losses from the piston have been reduced by 30%. The engine also features an optimized intake port, more conducive to air intake, a newly developed piston combustion chamber shape and a common-rail fuel injection system that achieves higher pressure and more advanced control of fuel injection pressure.
Precise pilot injection matching the state of the ambient air occurs before the main injection to shorten ignition delay, achieving stable combustion even in the world's harshest environments, while ensuring quiet operation and high thermal efficiency, said Toyota.
The GD engines also utilize a newly developed turbocharger (produced in-house by Toyota) that is 30% smaller than its current equivalent, and features a newly developed turbine that improves efficiency, and a newly developed impeller that provides instantaneous acceleration response and produces maximum torque over a wide range of engine speed.
The configuration of the aftertreatment system depends on the market. Engines for the Asian, Middle Eastern and Latin American markets utilize a DOC aftertreatment, while engines destined for Australia and Russia are fitted with a DOC+DPF system. Vehicles for the Japanese and European market utilize a DOC+DPF+SCR aftertreatment that enables meeting Euro 6 or the Japanese 2010 emission standards.
By moving the catalyst close to the engine, the catalyst size has been reduced by about 30% and the number of exhaust system layouts reduced from 18 to three, simplifying the global deployment process. The Toyota's “proprietary, compact, high-dispersion urea selective catalyst reduction system” eliminates up to 99% of NOx, said the company (the test cycle or conditions were not specified).
The SCR system is placed in the underfloor position, downstream of the close-coupled DOC+DPF unit. The urea pump module is integrated into urea tank. The urea injector is positioned in front of a smaller, one-brick SCR converter, which is followed by a second, two-brick converter positioned further away from the engine. It remains unclear whether other types of catalyst are used, such as passive NOx adsorbers, to help achieve the impressive NOx reductions.
The current globally deployed Toyota KD engines will be gradually phased out and replaced with the GD engines. By 2016, the production is scheduled to reach 700,000 units a year with introduction in approximately 90 markets, set to expand to at least 150 markets by 2020. Toyota said it will continue to position diesel engines as a key component of their engine lineup, based on the philosophy of providing the right vehicles for the right places at the right time.
Source: Toyota