We combined data from six studies, all using the same speed of processing training program, to examine the mechanisms of training gain and the impact of training on cognitive and everyday abilities of older adults. Results indicated that training produces immediate improvements across all subtests of the Useful Field of View test, particularly for older adults with initial speed of processing deficits. Age and education had little to no impact on training gain. Participants maintained benefits of training for at least 2 years, which translated to improvements in everyday abilities, including efficient performance of instrumental activities of daily living and safer driving performance.