Quote:
Originally Posted by RockCrusher
Info I have (Bosch) is the return to a mix of direct and port injection is not due to deposit issues -- Bosch addresses deposit issues with the recommendation to use gasoline with detergents -- but rather to obtain better combustion by making use of the intake valve heat.
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Thank you. I looked up your info on the web and found the explanation clearly:
"Key Reasons for the Return to Dual Injection (Bosch):
Improved Combustion and Lowered Emissions: Bosch indicates that combining DI and PFI provides superior control over the air-fuel mixture across various operating conditions (partial to full load). Port injection excels at homogenization at low speeds, while direct injection is used to increase the knocking limit at high loads.
Operating Strategy Optimization: The two systems work in a "division of labor," reducing fuel consumption and emissions.
Intake Valve Cleaning as a Secondary Benefit: While not the primary driver in Bosch’s technical descriptions of the partnership, the PFI system does spray fuel into the intake manifold, which cleans the intake ports and valves, allowing for higher exhaust gas recirculation (EGR) rates without penalty.
Addressing Deposit Concerns via Fuel: Bosch addresses deposit issues primarily through the recommendation to use high-quality fuels with appropriate detergent packages".