From french fries to fire trucks — that’s the goal of Oakland Mayor Libby Schaaf’s plan to use diesel made from used cooking oil, grease and other waste from local restaurants.

The city has been running its fleet of vehicles on biodiesel since 2015.

Now Oakland is upping the program a notch by partnering with Finnish energy company Neste and Western States Oil.

Under the plan, trucks will pick up used cooking oil. It will then be shipped it to Neste’s processing plant in Singapore, where it will be processed into biodiesel, then shipped back in what is being billed as a “circular fuel economy.”

Price: about $4 per gallon — about the same price as regular diesel.

So now, “when Oaklanders eat french fries at Luka’s or TrueBurger, they’re putting fuel into our fire trucks,” Schaaf said.

Pass the ketchup.

San Francisco Chronicle columnist Phillip Matier appears Sundays and Wednesdays. Matier can be seen on the KPIX-TV morning and evening news. He can also be heard on KCBS radio Monday through Friday at 7:50 a.m. and 5:50 p.m. Got a tip? Call 415-777-8815, or email pmatier@sfchronicle.com. Twitter: @philmatier