A police officer on patrol noticed smoke at 62 W. El Camino Real and reported the fire at about 11:50 p.m., Mountain View police spokeswoman Liz Wylie said.
Firefighters evacuated five units of a nearby housing complex as a precaution but were able to extinguish the fire by about 12:25 a.m., fire department spokeswoman Jaime Garrett said.
Crews had to work carefully because there was a danger that other vehicles and a 500-gallon propane tank nearby would ignite, Garrett said.
Seven trucks were severely damaged while one sustained minor damage, she said. A damage estimate was not available today.
Arson investigators were still at the scene this morning trying to determine the cause of the fire.
The U-Haul facility had been targeted in a gas-siphoning scheme for about the past 10 months, Wylie said.
The company estimated that about $30,000 worth of gas had been stolen from the trucks, which are parked in a large lot accessible by a driveway, she said.
The siphoning had recently stopped after managers started blocking off the driveway by lining up some of the trucks, Wylie said.
"Based on the amount of gas being siphoned, we don't think it was one person walking in with a plastic canister," she said. "We think it was more organized crime where people were coming with vehicles."
It was too early to tell today whether the fire was related to the siphoning, Wylie said.
A U-Haul employee said the business is open today but declined to discuss specifics of the case, which is still under investigation.
Wylie said police are reviewing footage from a couple of security cameras at the parking lot.
Police briefly shut down El Camino Real in both directions while the fire was burning, along with a block of state Highway 237 that intersects with the thoroughfare, she said.
No one was injured in the fire.