Efficiency in reading component skills is crucial for reading comprehension, as efficient subprocesses do not extensively consume limited cognitive resources, making them available for comprehension processes. Cognitive efficiency is typically measured with speeded tests of relatively easy items. Observed responses and response times indicate the latent variables of ability and speed. Interpreting only ability or speed as efficiency may be misleading because there is a within-person dependency between both variables (speed--ability tradeoff [SAT]). Therefore, the present study measures efficiency as ability conditional on speed by controlling speed experimentally with item-level time limits. The proposed timed ability measures of reading component skills are expected to have a clearer interpretation in terms of efficiency and to be better predictors for reading comprehension. To support this claim, this study investigates two component skills, visual word recognition and sentence-level semantic integration (sentence reading), to understand how differences in ability in a timed condition are related to differences in ability and speed in a traditional untimed condition. Moreover, untimed and timed reading component skill measures were used to explain reading comprehension. A German subsample from Programme for International Student Assessment (PISA) 2012 completed the reading component skills tasks with and without item-level time limits and PISA reading tasks. The results showed that timed ability is only moderately related to untimed ability. Furthermore, timed ability measures proved to be stronger predictors of sentence-level and text-level reading comprehension than the corresponding untimed ability and speed measures, although using untimed ability and speed jointly as predictors increased the amount of explained variance.