The adoption of gaseous fuels for light duty engines is considered a promising solution to efficiently reduce greenhouse gases emissions and diversify fuels supplies, while keeping pollutants production within the limits. In this respect, the Dual Fuel (DF) concept has already proven to be, generally speaking, a viable solution, industrially implemented for several applications in the high duty engines category. Despite this, some issues still require a technological solution, preventing the commercialization of DF engines in wider automotive fields: the release of high amounts of unburned species, the risk of engine knock, the possible thermal efficiency reduction are some factors regarding the fuel combustion aspect. In this framework, the numerical simulation of combustion in DF mode can be a useful tool, not only to better understand the peculiarities of its evolution, but also to explore specific geometrical modifications and engine calibrations capable to adapt current LD architectures to this concept. Nevertheless, due to the significant differences of DF combustion both from spark ignition and compression ignition combustion, its numerical simulation requires specific solutions, modifying the classic approaches traditionally adopted for internal combustion engines simulation. The research activity described in this paper aims at evaluating and improving the applicability of some numerical models, already assessed in Diesel combustion, to combustion in a LD engine working in DF mode. The validation activity is carried out thanks to a wide experimental campaign on a single cylinder Diesel engine, properly modified to work in Dual-Fuel mode. Several operating conditions, ranging from low to high engine load, have been selected to be reproduced numerically by means of the LibICE library, relying on the OpenFOAM software platform, employing detailed chemical reaction kinetics. Numerical results focus on autoignition, combustion pattern and pollutants formation in realistic DF conditions for LD engines.