A stash of grass can take the place of a lot of gas, but it won't do anything for mileage.

A Utah man took his newly acquired used SUV to a mechanic to find out why the gas gauge always read half-full.

The mechanic in Sandy looked inside the gas tank and found about 35 pounds of marijuana in plastic-wrap packages that filled about half of the tank's volume.

Police estimate the pot is worth about $35,000.

The Nissan Armada has had several different owners and was once a rental car.

Sandy police are trying to figure out who stashed the pot but say the current owner is not a suspect.

Investigators in the town south of Salt Lake City say the drug packs could have been in the tank for months.