The Volkswagen recommended tire pressure for the 2004 VW Golf R32 is a little unusual in that it's different for the front (35 psi) and rear tires (44 psi). These VW bona fide manufacturer recommendations are described in my owner's manual and on the driver door jam sticker. What puzzles me is that in the past seven years of R32 ownership, whether it be VW service departments in Maryland or Virginia, whether in the United States or Canada, they without fail under inflate the R's rear tires. I long ago gave up mentioning it because it never makes a difference. VW service invariably deflate my R's rear tires before returning it to me, setting all four tires at 35 psi. Maybe they know something I don't? If so, it would be nice if someone from VW would inform me that the tire pressures in the owner's manual and door sticker are incorrect.
To improve smoothness throughout the rpm range and help lower noise levels, the Accord Hybrid is fitted with an internal balancer unit. Consisting of a pair of chain-driven counter-rotating shafts located in the oil pan, the balancing system helps quell the inherent second-order harmonic vibrations that are normally associated with inline 4-cylinder engines. The 2.0-liter engine has cylinder bores offset by 6.0 mm from the crankshaft to help reduce piston-sliding friction. This gives the connecting rods a more favorable angle during each power stroke, which reduces side loading on the pistons and, in turn, improves efficiency. The lightweight pistons have a carefully optimized skirt design to minimize reciprocating weight, and reduced weight minimizes vibration and increases operating efficiency. The Honda Accord Hybrid engine has a lightweight cylinder head that is made of pressure-cast aluminum alloy. A silent chain drives dual overhead cams and four valves per cylinder. The cam drive is maintenance free throughout the life of the engine.
To help boost fuel efficiency and power, the engine has a 34-degree included angle between the intake and exhaust valves. The narrow valve angle decreases the surface-to-volume ratio and helps create a flatter, more compact combustion chamber that reduces unburned hydrocarbon emissions. This combustion chamber shape and the precise control enables a high compression ratio of 13.5:1, yet the engine still operates on regular unleaded fuel. The Accord Hybrid's 2.0-liter DOHC 16-valve i-VTEC engine uses an advanced valve-control system to combine high power output with high fuel efficiency and low emissions. The system combines E-VTC (Electronic Variable Timing Control), which continuously adjusts the intake camshaft phase, with Variable Valve Timing and Lift Electronic Control (VTEC), which changes the lift profile, timing and duration of the intake valves' operation. A key contributor to the Accord Hybrid's excellent emission performance is a single dual-bed catalytic converter. The converter mounts directly to the front of the cylinder head, close coupled for fast activation after the engine is started.
It uses a thin-wall design that increases internal reaction area and improves efficiency. A high-efficiency exhaust system and the dual-bed, high-density catalytic converter help the Accord engine meet stringent LEV3- AT-PZEV(SULEV30)/Interim Tier3 Bin30 standards, which require reduced greenhouse gases compared to lower standards. The heat recovery device contributes to the third-generation i-MMD's efficiency by helping to reduce power-robbing friction, particularly during cold-weather startup and initial operation, prior to engine warmup. Located downstream on the exhaust system, the heat recovery device uses hot exhaust gas to warm engine coolant quicker, especially during cold weather conditions. This brings the engine up to normal operating temperature quicker, reducing internal friction and allowing the i-MMD to operate in electric mode earlier. This helps improve fuel efficiency during cold weather operation. The 2018 Accord Hybrid uses two new-generation electric motors, a propulsion motor that drives the wheels and a generator motor that produces electricity, both of which have been upgraded from the previous generation i-MMD. The Honda-developed electric motors that are the first permanent magnet drive motors in the world to use magnets containing no heavy rare-earth metals. The propulsion motor is rated at 181 horsepower and 232 lb.-ft.
When in regenerative mode, the propulsion motor converts the kinetic energy of the decelerating vehicle into electrical energy to recharge the battery. Its operation is seamlessly coordinated with the Accord Hybrid's electric-servo braking system. A separate generator motor is driven by the gasoline engine to generate electric energy to drive the propulsion motor when the vehicle is operating in Hybrid Drive Mode. This generator motor can also restart the gasoline engine when the vehicle is in idle-stop mode. The Honda Accord Hybrid's completely reworked intelligent Power unit (IPU) is now 32-percent more compact and has been repositioned under the rear seat base, instead of in the trunk, behind the rear seatback as in the previous generation Accord Hybrid. This repositioning means that the Accord Hybrid offers the same roomy trunk utility and 60/40 split-folding rear seatback versatility of the non-hybrid Accord models. The IPU packages a reconfigured Li-Ion battery pack that powers the Accord Hybrid's electric propulsion motor. Improved battery control systems and revised battery chemistry allow the new battery to operate over a broader state-of-charge range for improved efficiency.
