Date posted: 08-08-2008

PEBBLE BEACH, California — Jay Leno describes his custom "tank car," derived from an M-47 Patton tank, as "probably the most inefficient fueled vehicle ever devised." But that thirsty gas hog and three others like it will be front-and-center at a special 20-plus-liter class at the 2008 Pebble Beach Concours d'Elegance.

"This is a tongue-in-cheek class not based on anything but fun," said Leno, anticipating the critics of this supersized class, which organizers describe as a "one-year-only display."

The display will include the only extended-chassis 200-horsepower 1913 "Blitzen" Benz and a custom Rolls-Royce modified to fit a massive 27-liter Rolls-Royce Merlin aircraft engine taken from a P-51 fighter plane. Another 20-plus-liter offering will be the 1953 Swandean Spitfire Special, which uses a Rolls-Royce Spitfire engine on a hand-fabricated chassis.

Show organizers point out that most semi-truck engines top out at 13 liters.

Leno admits that "there's no practical purpose to (the tank car) other than it's just fun and people get a kick out of seeing it.... In an era where things are getting smaller and smaller, this is a throwback to a time when things were really, really big," said the Tonight Show host.

What this means to you: This display should make you feel good, especially if you've accused your ride of being too thirsty. — Anita Lienert, Correspondent, www.edmunds.com