The act of jumping into a vehicle with all of your buddies and a cooler full of ice cold beer, and driving around the countryside at any time of the day. This was more popular in the country where there are lots of open sideroads. The intent is to relax and enjoy each other's company, and indulge in a few cold ones. The driver is also encouraged to drink.
Beer Touring has declined in popularity in recent years, due to the po-po cracking down on drinking and driving.
"Where are Jimmy and Jake and the rest of the boys?"
"They're out on beer tour."