The sales of full-size vehicles in the United States declined after the early 1970s fuel crisis.[8] By that time, full-size cars had grown to wheelbases of 121–127 inches (3.1–3.2 m) and overall lengths of around 225 in (5,715 mm).[citation needed] In response to the 1978 implementation of CAFE, American manufacturers implemented downsizing to improve fuel economy, with full-size vehicles as the first model lines to see major change.