The Marijuana Policy Project is set to run an ad during NASCAR’s Indianapolis Motor Speedway event this weekend.
A pro-marijuana legalisation ad will play 72 times over three days on a huge screen near the race's entrance gates.
The $350 ad has distinctly anti-beer messaging, highlighting that with marijuana there are "no calories," "no hangovers," and "no violence", which will no-doubt jar against NASCAR's official sponsors, Crown Royal Whisky and Miller Lite.
"We think it's critical that the public recognise that marijuana is objectively less harmful than alcohol," Mason Tvert, spokesman for Marijuana Policy Project, told ABC's News10.
Over the three-day weekend race, it is estimated that more than 600,000 fans may see the advert.
NASCAR has not commented on the ad, but says it has no affiliation with the advertiser or the company selling the inventory, Grazie Media, and it will not appear on any NASCAR controlled property.
The campaign comes despite a recent study by The Partnership at Drugfree.org, which suggested 80 per cent of Americans are anti-marijuana marketing.