I wouldn't use a tarp. They tend to rub the sides and corners, causing a sanded type of effect. Better to use a cover that's designed for weather and wind. They don't last long though...depending on your local weather. If you have rain spouts, be sure to use tennis balls. They keep the cover from ripping and tearing due to wind.
2013 Jayco Eagle 328 RLTS
2012 Ford F250 6.2L 4x4 CCSB W/Air Lift air bags
2002 Coleman Bayside Elite (traded)
Me, Momma and Charles (RIP buddy)
And introducing Sofie!! ;)