This paper examines the relative efficiency in the German engineering industry. Applying recently developed DEA methods on roughly 23,000 observations between 1995 and 2004 three expectations are tested: (i) there is a left skewed efficiency as expected in competitive industries, (ii) efficiency increase with firm size (iii) the expected efficiency gap between size classes is stable. The results reject the first two expectations. The efficiency scores are almost normal distributed with an overall mean of 0.69. Although the efficiency differs significantly with firm size, medium-sized firms are the least efficient on average. The efficiency gap narrows over time.