An apparatus of controlling an engine includes a controller determining an inflow fuel amount adsorbed on an inner wall of a cylinder, and introduced into an oil pan based on the density of a combustion chamber and a post injection fuel amount, determining a vaporization fuel amount vaporized in the inflow fuel amount based on an operating condition of an engine, determining a consumption fuel amount consumed in the vaporization fuel amount based on the operating condition of the engine, and determining a dilution rate of the engine oil based on the inflow fuel amount, the vaporization fuel amount, and the consumption fuel amount; and a display providing an alarm to a driver when the dilution rate of the engine oil is equal to or more than a reference value.

An apparatus of controlling an engine includes a controller determining an inflow fuel amount adsorbed on an inner wall of a cylinder, and introduced into an oil pan based on the density of a combustion chamber and a post injection fuel amount, determining a vaporization fuel amount vaporized in the inflow fuel amount based on an operating condition of an engine, determining a consumption fuel amount consumed in the vaporization fuel amount based on the operating condition of the engine, and determining a dilution rate of the engine oil based on the inflow fuel amount, the vaporization fuel amount, and the consumption fuel amount; and a display providing an alarm to a driver when the dilution rate of the engine oil is equal to or more than a reference value.

A method (500) and apparatus (10-5) for carrying out the method of mitigating fuel in oil in an internal combustion engine of a hybrid electric vehicle, the method comprising: determining an amount of fuel flow into the engine oil during one or more cold start phases of engine operation (505); determining an amount of fuel flow into the engine oil during one or more enrichment phases of engine operation (510); determining an amount of fuel evaporated from the engine oil during one or more phases of vehicle operation with the engine on (515); determining an amount of fuel evaporated from the engine oil during one or more phases of vehicle operation with the engine off (520); determining a percentage of fuel in the engine oil from the amount of fuel flow into the engine oil and the amount of fuel evaporated from the engine oil (525); and modifying vehicle operation based on the percentage of fuel in the engine oil exceeding a first fuel in oil threshold or a second fuel in oil threshold (540).

A control system for controlling fuel delivery to an internal combustion engine (ICE) based on oil diluted by fuel in a crankcase of the ICE includes a fuel injector and a controller. The controller is configured to determine a modeled evaporation rate of unburned fuel in the crankcase; compare the modeled evaporation rate of unburned fuel to a threshold; and communicate a fuel delivery signal indicative of an injector fuel mass target to the fuel injector to compensate the fuel injected based on the modeled evaporation rate of the unburned fuel in the crankcase exceeding the threshold.