Last year was a record for US vehicle recalls - more than 53 million in 927 separate recalls - but those numbers are only the latest, with the total number of recalls increasing in each year back to 2011 when the number stood at 13.6 million, according to information from the National Highway Traffic Safety Administration.
The agency said it did not find the request by the second largest USA automaker to defer a recall until additional testing was conducted "reasonable under the circumstances or supported by the testing and data it has collected to date".
Takata inflators can explode with excessive force, unleashing metal shrapnel inside cars and trucks. About 18 deaths and 180 injuries globally have been connected to the defect that resulted in Takata Corp to file for bankruptcy protection in June and triggered at least 19 automakers to issue recalls.
NHTSA also rejected a similar petition filed by Mazda Motor Co covering about 6,000 vehicles. Mazda said in a statement it "takes our consumers' security as a single-minded top priority and continues to work together with NHTSA".
The public can comment on NHTSA's decision until December 18 on both Ford and Mazda's petitions.
Ford did not immediately say if it plans to challenge the agency's decision. The vehicles in question concerns the 2007-11 Ford Ranger, 2006-12 Fusion and Lincoln MKZ, 2006-11 Mercury Milan, and 2007-10 Ford Edge and Lincoln MKX.
In July, NHTSA stated new testing prompted Takata to declare inflators faulty in Ford, Nissan Motor and Mazda automobiles in some driver-side air bags.
Almost two-thirds of the USA vehicles containing defective airbag inflators made by Takata Corp. remain unrepaired as automakers have made varying degrees of progress addressing the largest auto recall in US history.
In 2019, another 4.1 million vehicles will be recalled to replace interim fix inflators.
In total, 43 million inflators have been recalled to date and 25 million still need replacements, as some vehicles have two defective airbags.
Takata has said it expects to have recalled 125 million vehicles worldwide by 2019.