It is aiming to bolster RAC Insurance's customer base by two-thirds to reach 900,000, and is targeting an additional 800,000 RAC Rescue members, to reach 3m.
The RAC has spent £11m on advertising in the past 12 months. It is understood that this will be raised to something nearer the budget of sister firm Norwich Union, which spends almost £50m a year.
The RAC moved its advertising from Windmill Partnership to Abbott Mead Vickers BBDO in June.
The increased investment will come partly from cost savings achieved after Aviva combined most of the RAC's marketing function with Norwich Union, following its £1.1bn takeover.
The merger led to several senior marketing casualties, including the departure this summer of RAC commercial director David Lewis.