Experimentally, Wood et al. observed a higher surface coverage for fatty acids with fewer Z-unsaturated groups (stearic > oleic > linoleic) at equal concentration. Campen et al. showed that unsaturated OFMs gave higher friction that was independent of the sliding speed, which can be explained in terms of a low surface coverage. At equal surface coverage Ewen et al. found similar friction for both saturated and unsaturated fatty acids in NEMD simulations, ascribing the differences found experimentally to the superior ability of saturated OFMs to form high-coverage monolayers with respect to their unsaturated counterparts. This difference between saturated and unsaturated OFMs is not reproduced with the present methodology. The form of the MTT model that has been used here only depends on the hard-disk area and the adsorption energy. The former is very similar for both GMS and GMO, since it is mainly determined by the headgroup, while the latter is more negative for GMO, due to its additional Z-alkene adsorption site.