In this paper, the surfaces of the two lands of twin oil control ring were investigated, since they play the key role in controlling the desired low emission and fuel levels designed for modern internal combustion engines. The goal is to map the variation in surface roughness of piston rings that appear at different scales from form and waviness to micro and nano roughness. Areal topography measurements were made by white light interferometer designed at the Halmstad University able to measure and scan the total functional area of the set of commercial piston rings. The results show both the variation and uncertainty of ring topography. The most stable parameters were found and recommended for an effective quality control.