The bar was set by the Le Mans winning C-Type and D-Type of the 1950s, raised higher by the glitz of the '150mph' E-Type the following decade, and then knocked off by the portly XJS from 1975. So what happened?
You can date the moment Jaguar swung away from its sports car path: October 13, 1956, when Jaguar officially stopped racing. "Lyons said to me one day, 'Dewis, you're spending too much time racing and not enough on production'. And that was it, we stopped," Dewis tells PistonHeads. "He would not increase the time to cope with both - he was very tight with the money."
Happily the E-type launched in 1961 was based on the race-winning D-type and kept much of that car's sporting genes. The independent rear suspension, disc brakes, that wonderfully slippery aerodynamic shape, the absence of a separate chassis - all these meant it could be called a sports car without fear of contradiction.
The racers clamoured for lightweight versions and Jaguar's sporting crown stayed on.
But Lyons became dependent on the dollar. "By the time the XJS came out our main market was America - 75 per cent of production went there," says Dewis.
And that meant giving them what they asked for. "They said, although we like the E-T
ype, it's a little bit small inside. They wanted a sports car, but with automatic transmission, power steering... They controlled our style and shape."
Pretty soon the view of car buyers this side of the pond were all but dismissed. "Take brakes. I'd say they're okay for America, but we'll have to change them for Europe. He'd say, 'Dewis, I'm not bothered about Europe. Why do I need to bother about Europe?'"
Dewis is impressed. "This is getting Jaguar to where it always should be. A good saloon car and a good sports car."