The Series 40 Defender was a four-seat passenger car produced by General Motors for its Oldsmobile division in 1912 and 1913, and was manufactured at Lansing Car Assembly in Lansing, Michigan. It continued to be the entry-level model for Oldsmobile, while Oakland Motor Car Company remained GM's entry level brand as Chevrolet didn't join GM until 1917. The Series 40 was the base model of three platforms sharing a platform with the Buick Model 10, with the mid-range Series 28 Autocrat, and the top level Series 23 Limited.