Diesel engines operate on a compression-ignition principle, where the high compression of the air in the cylinders creates heat that ignites the diesel fuel. Unleaded gasoline has a lower flash point and auto-ignition temperature compared to diesel, meaning it ignites more easily. This can lead to pre-ignition (knocking) in a diesel engine, which puts excessive stress on the engine components and can cause severe damage to pistons, piston rings, cylinder walls, and bearings.
Additionally, because of their different properties, diesel and unleaded have different combustion rates. The fuel injection and timing in a diesel engine are specifically designed for diesel fuel's slower burn rate, and using unleaded gasoline disrupts this process, resulting in incomplete combustion or misfires leading to reduced performance and increased emissions.
Furthermore, diesel fuel acts as a lubricant for certain components in the engine, like the fuel injector pump and seals. Unleaded gasoline lacks such properties and can result in premature wear and increased maintenance costs.
Using unleaded gas in a diesel engine can cause irreparable damage, necessitating costly repairs or even full engine replacement in some cases. If mistakenly filled with unleaded fuel, do not start the engine. Immediately contact relevant roadside assistance professionals to drain the gasoline, clean the fuel system, and refill it with the correct diesel fuel before attempting to start the engine.
