For 2025 the North American market Honda Civic Hybrid gained a new fourth-generation two-motor hybrid powertrain option that features better performance and efficiency than previous versions, if not best-in-class metrics. In fact it has been named one of “Wards 10 Best Engines & Propulsion Systems”.
The system is comprised of a 2.0-liter Atkinson-cycle naturally aspirated four-cylinder engine with 141 horsepower and 134 pound-feet of torque. It’s mated to a next-generation two-motor electronic continuously variable transmission that can operate in both series and parallel modes.
It’s main traction motor has 181 horsepower and 232 pound-feet of torque and is mounted in-line with a motor-generator that can both start the engine as well as charge its 1.06 kWh lithium-ion battery which is mounted under the rear cargo floor. All together the system offers up a total of 200 system horsepower.
Following the airflow, the intake charge starts at the front of the engine bay through an intake snorkel and through a series of plastic plenums as it routes it way back over the top of the aluminum case of the liquid cooled hybrid control unit.
At the rear of the engine it’s drawn through a small air filter box and then past a mass airflow sensor before dropping down into the intake manifold. From there it flows into a 16-valve head with variable cam timing and valve lift for the intake cam.
You can see atop the head all four spark plug coil packs. The direct fuel-injection however is mostly hidden though you can see the high-pressure fuel pump at the right top of the engine. Once the combustion process is complete the exhaust air exits through an integral manifold into the main catalyst and straight down. Off to the right you can see this engine features a liquid cooled EGR system.
Care and maintenance on the Civic Hybrid is straight forward. The oil cap can be found at the left top of the engine and the oil check dipstick just ahead of it. Both can be accessed with the foam engine cover on or off. The oil filter however must be accessed from below.
Brake fluid can be found at the driver side firewall. Notable here is that the brake system itself is spread out, with the main master cylinder actually at the passenger side, the ABS control unit further ahead at the front of the engine bay.
Windshield washer fluid can be found at the passenger side fender line visible by its bright blue cap, though not as easily found with the color of this particular car. There are two coolant reservoirs, one for the hybrid system found next to the brake fluid, the other for the engine found at the front and adjacent to the radiator.
It’s 12-volt battery is found at the driver side front of the engine bay, with the main engine control computer found just behind it. The main consumer grade fuse box is located further back against the shock tower, a handy fuse removal tool is provided inside.
Notable items around the engine bay include the air-conditioning compressor which is powered by the high-voltage battery, not belt driven. Always be cautious of the orange high-voltage wiring as it carries lethal voltage. Also note the electric cooling fans at the radiator, keep your hands clear of these even if the engine is turned off.
