The event is time to precede Pioneer Day celebrations so the troops can travel safely during the holiday, said Willey spokeswoman Patricia Byrne.
A free barbecue will accompany the event, which will take place at 1800 South Main Street. Military members should bring their military identification cards.
This is the first time Willey Ford has offered the free oil changes for military.
"It's just our way of saying thank you for all those that have done so much for our country," Byrne said.