The race, which was originally scheduled to be run on Sunday, was rescheduled for 10 a.m. EDT today.
Officials said it would be the first time in NASCARs modern era, dating to 1973, that a race has been run on a Tuesday.
The last time a Cup race was postponed for two consecutive days was April, 1997, at Talladega, Ala. That event was run two weeks later, after a race at Sonoma, Calif.
The National Weather Service forecast for today called for a 30 percent chance of rain.
NASCAR spokesman Ramsey Poston said the race could be run as late as Wednesday, with the Cup transporters due to arrive in Bristol, Tenn., Thursday afternoon to set up for Saturday nights race.
It looks like we can do it logistically Wednesday, if necessary, Poston said.
There was a steady stream of motorhomes and RVs leaving the track Monday as heavy rain fell in the morning and peoples hopes faded. About 1,000 fans sat in the vast grandstand in the afternoon, trying to wait out the weather.
Most of the drivers spent Monday hanging around their motorhomes, walking their dogs or wandering around the infield when the rain let up briefly, and hoping the race would be run. At one point, about 2 p.m., the track was being dried and appeared within about one hour of being ready to race, but a misty rain began to fall again and NASCAR finally gave up for the day at 4 p.m.
The drivers found different ways of amusing themselves.
Weve just been playing Nintendo in the motorhome, and we got cabin fever last night, said Carl Edwards, who won the June race at MIS. We went to the university in Adrian (Mich.) and they let us use the gym there. So me and my trainer and my motorcoach driver went and worked out.
Then we came back to the motorhome for as long as we could and we took our little (ATV) out and ran around the infield in the rain and met some folks and had a pretty good time.
Kasey Kahne said he was just bored by the long wait.
With the weather, weve just spent a lot of time in the rain or just waiting and there isnt a lot to do in these motorhomes, he said. You run out of movies to watch, TV shows, and these satellite dishes dont work when it rain as hard as it has. You just wait and hope it quit raining so you can get out on the track.
Kahne said the heavy overnight rains since Saturday have even kept him from getting much sleep.
Usually, when it rains, I can sleep, he said. But its been coming down so hard on the motorhome the last couple of nights I can barely sleep. Its been some serious water out here.