Two track tests were performed using European cab over vehicles in a two vehicle platoon to determine the aerodynamic benefits of driving in a platoon. The first test, performed in January tested following distances of 10, 20, 30, 40 & 50 m. As the adaptive cruise control was inoperative, the distance was measured using radar, and manually controlled. Weather conditions were wintery and wind speeds were above average, leading to yaw angles of 5°. Fuel measurements using CAN bus data showed that the leading vehicle experienced no savings for following distances other than 10 m. For the following vehicle, at the largest distance of 50 m savings of 9.0 ± 2.8% were achieved. Decreasing the distance to 40, 30 and 20 m did not yield any significant savings over a following distance of 50 m. At a separation distance of 10 m the savings increased somewhat to 10.6 ± 3.1%.The second experiment was conducted during August, with more stable conditions. Wind speeds were low, and the resulting experienced yaw angles were below 2°. During the second test, the adaptive cruise control was used to maintain the distance. The distances of the first test were repeated with an additional distance of 70 m. The results showed similar results for the Leading vehicle, no significant savings for any of the separation distances except the 10 m separation distance, which resulted in a saving of 4.0 ± 0.7%. The savings achieved with the following vehicle were generally higher than those achieved in the first test. For 50, 40, 30 and 20 m the results were around 1.5% higher than in Test 1. For 10 m separation distance, the result achieved (10.1 ± 0.9%) was lower than the result at 20 m distance, and similar to the value achieved in Test 1. The authors suggest that the difference results between the two tests can be attributed to the difference in wind conditions, and the resulting difference in yaw angles. As there were significant differences between the two tests in weather and road conditions and setup, such as different tractor and trailers, distance control method, the authors cannot determine a single cause. The results achieved with the leading vehicle match the results of literature well. For the following vehicle there is more spread in the existing work, and the data matches the lower end of the spread well. The authors conclude that for the range of separation distances tested the leading vehicle gains from the closer following distances, but that for the following vehicle close proximity platooning has a limited potential for improving fuel consumption over current day legal platooning distances.