The objective of this study is to investigate the air side thermal-hydraulic characteristics of rectangular finned elliptical tube heat exchangers (RFETHXs) using 3D numerical simulations based on the validated standard k-epsilon turbulence model. First, fin efficiency of RFETHXs is investigated. The effects of various parameters such as row number, transverse tube pitch, longitudinal tube pitch, fin pitch, fin thickness and Re have been studied. Then the influences of structural parameters on the thermal-hydraulic performance of RFETHXs are examined, not only the characteristics including the effect of fin thermal resistance but also the pure convective performance excluded this effect. The contribution ratios of each structural parameter on fin efficiency and air side thermal-hydraulic performance are given. It is observed that, the most important structure factors for fin efficiency are fin thickness and fin pitch. For the RFETHXs with fully developed air side flow and heat transfer (N > 5), from the third row to the last second row, the average fin surface Nu of each row is almost stable, and the value of the second row is 9% higher than the stable value. The results show that the air side heat transfer performance and friction factor of RFETHXs is mainly determined by the transverse tube pitch. For j/f(1/2) at fixed Re, the contribution ratio of transverse tube pitch is 32% while the value is 24% at fixed frontal velocity. Moreover, two sets of multiple correlations, both including and excluding fin thermal resistance, are proposed to describe the air side heat transfer and friction characteristics of RFETHXs in turbulent flow regime. (C) 2017 Published by Elsevier Ltd.