Pistons and shafts overheat and seize up unless protected by a slick, shiny coating of oil, just like classical Greco-Roman wrestlers. Keep your engine parts from throttling each other with today's Groupon: for $20, you get a full-service conventional oil change (up to a $41.59 value) at Grease Monkey Quick Lube. Choose between two sets of locations:

• Court House Road and Midlothian Turnpike.
• North Boulevard and Staples Mill Road.

During the 30-minute full-service oil change, Grease Monkey's mechanics pump vehicles with up to five quarts of oil and provide a thorough checkup to sustain smooth pavement sailing. Motor doctors examine your auto's respiratory system, including its air filter, breather element, and PCV valve, and a check of the exterior lights and windshield wipers maintains the vehicular vision of a carrot-loving mother hawk. Dehydrated vehicles get big gulps of fluids for their power steering, battery, windshield, transmission or transaxle, differential, and engine coolant. Inside, a vacuum eviscerates lint, pebbles, and pixie dust, and nimble hands turn mud-caked window exteriors into transparent bastions of clarity.

Though Grease Monkey sometimes features a discounted price online, this Groupon still offers the best deal available.