One of the problems with GDI(Gasoline Direct Injection) engines stems from small particles of oil/dirt that can blow back from the crankcase ventilation system and deposit onto the walls of the intake port and the back of the valve. Carbon sticks to the valve because fuel doesn’t spray down the back of the valves like in a port-injected system. The buildup can become significant enough that a piece can break off and damage the catalytic converter. It also can cause ignition problems.
I recently found the above post from someone on the CivicX forum. Nice to know the Insight uses port injection for the gasoline engine. More reasons to get an Insight over a Civic, no worries about carbon buildup, or oil dilution. :wink:
Edit: Found the spec sheet for the Insight.
Two-Motor Hybrid Powertrain
- Total system output: 151 horsepower
- 1.5-liter, DOHC, i-VTEC® Atkinson-cycle inline 4-cylinder engine
- Engine output: 107 peak horsepower (SAE net) at 6,000 rpm
- Engine output: 99 lb.-ft. peak torque (SAE net) at 5,000 rpm
- i-VTEC® (Variable Valve Timing and Lift Electronic Control + Electric VTC)
- Computer-controlled port fuel injection with multi-hole fuel injectors
- 13.5:1 compression ratio
- AC synchronous electric traction motor
- Propulsion motor output: 129 horsepower and 197 lb.-ft. of torque
- Generator motor
- Maintenance Minder™ system optimizes service intervals
- 100,000+/- miles engine tune-up interval
- Regular Unleaded fuel recommended
- 60-cell lithium-ion (Li-Ion) battery
- Electric-servo regenerative braking system
- Lock up clutch drive force transfer
- Eight-year/100,000-mile or ten-year/150,000-mile Li-Ion battery limited warranty, depending on the state of purchase/registration
Differences between the 3 generations of Honda's 2-motor hybrid system.
The
first-generation of Honda's two-motor system was introduced on the 2014 Accord Hybrid and Accord Plug-In Hybrid. The
second-generation system, featuring a more compact and powerful electric propulsion motor and a more efficient lithium-ion battery pack, first appeared on the refreshed 2016 Accord Hybrid, where it was paired with a 2.0-liter Atkinson cycle engine, and more recently on the 2018 Clarity Plug-in Hybrid, where it is paired with a 1.5-liter Atkinson cycle engine. This
third-generation system is utilized on both the new Insight and new 2018 Accord Hybrid, each featuring a uniquely-sized engine, motor and battery pack, based on the different size and power demands of the vehicles.
Major improvements over the second-generation system include:
- A 32 percent reduction in the size (volume) of the Intelligent Power Unit (IPU), containing the lithium-ion battery pack, made possible by the relocation of the DC-DC converter from the IPU to the Power Control Unit (PCU) and by repackaging the battery cells to reduce structural components.
- Like in the Accord Hybrid, the DC-DC converter (previously built into the IPU) has been integrated into the PCU. Yet, the new PCU with built-in DC-DC as a unit occupies the same space, helping improve underhood packaging. The propulsion motor adopts a new proprietary magnetic circuit allowing the reduction of heavy rare metals including the complete elimination of dysprosium and terbium.