In the late 70s I remember buying and changing the oil in our 69 VW Beetle with Quaker State SAE 30. I have run straight 30s in several much newer cars over the years, an 87 Caprice that used some oil and in my 2004 Jeep I-6 over the summer months, both Pennzoil SAE 30. I have some Formula Shell SAE 30 in the garage right now, it's what's in the mower but it doesn't even take a quart.