The Cadillac Cimarron comes to mind when thinking about stricter CAFE standards and attempts at achieving greater efficiency. It was produced 1982-88 initially with a 1.8 liter 4-cylinder and later with a 2.8 liter V6. The 4-cyl model achieved over 30 MPG which made it the most fuel efficient Cadillac. But, some criticized it for being too similar to its sibling - the Chevy Cavalier and Pontiac J2000.