See golfing legend Arnold Palmer demonsrate a new Cadillac feature, the Tripmaster trip computer, in this pitch for the 1978 Seville.

As the most expensive car in the Cadillac lineup in those days, the 1976-79 Seville was not merely a success for GM’s luxury car division, it was a highly profitable one. And for the ’78 model year, among the major selling stories was Tripmaster, an early onboard trip computer, and it’s one of the featured attractions in our video below. A $920 option, it could track average miles per gallon, miles and time to arrival (if you entered the trip distance beforehand) and a few other items. It wasn’t terribly advanced by current standards, but it was a first step toward the sophisticated driving and navigation aids we know today.

The other featured attraction here, of course, is golfing legend Arnold Palmer, who was a Cadillac dealer and flying enthusiast as well as a four-time Masters winner. With two co-pilots, Palmer had recently set an around-the-world record for business jets with a Lear 36, and that angle is used here as he pitches the features of the Tripmaster. Otherwise, the Seville for ’78 was pretty much a continuation of the ’76-’77 cars, with a unit-construction platform loosely based on the X-body Chevy Nova and an Oldsmobile-sourced 350 CID V8 with electronic port fuel injection. Unlike a few other small Cadillacs that would come along later, the original first-generation Seville remains a well-regarded car. Video follows.