American Motors Corp. didn’t have enough money to subject the original Jeep Cherokee — the first modern SUV — to a traditional durability testing program ahead of its late 1983 launch.
But Roy Lunn, the Cherokee’s chief engineer, who died in Santa Barbara, Calif., on Aug. 5 at age 92, steered around the obstacle by securing credentials for the punishing Paris-Dakar Rally. Lunn’s engineering team prepared two Cherokees for the event, not to compete but simply to run the brutal desert course and monitor how the Cherokee’s “uni-frame” body would take the constant pounding over the bruising, potholed 6,200-mile course.
Only the shock absorbers needed frequent replacement and both vehicles finished the rally in good condition. Lunn knew his groundbreaking design, which featured a steel ladder frame welded to a unitized body, was robust enough to take almost anything consumers were likely to subject the Cherokee to.
Last year, just ahead of his induction into the Automotive Hall of Fame, Lunn told Automotive News the fuel shortages and price shocks of the 1970s influenced his thinking on the Cherokee’s technical design. “I chose unitized [construction] because it is stronger pound for pound, and it is lightest for meeting fuel economy requirements,” he said.
The most fuel-efficient Jeep Cherokee, a two-wheel-drive model with a 2.5-liter four-cylinder engine and manual transmission, was EPA-rated at 24 mpg city and 33 mpg highway in 1985 — figures that rivaled many family cars at the time.
The Cherokee not only was a monster hit for American Motors, and later Chrysler — more than 3 million were sold before production ended in 2001 — but it also became the template for the modern SUV and continues to be copied by virtually all major global automakers.
“What’s amazing about Roy is he had a laser focus on what the issue or problem was and he put all of his energies and thoughts into making it right,” said automotive journalist and author Martyn Schorr, who first met Lunn in the mid 1960s.
The Cherokee’s light weight, four-wheel drive, and high ride height but low floor for easy entry, offered rugged off-road capability but in a vehicle that felt and behaved more like a car. Earlier SUVs, such as the Ford Bronco and Land Rover Series 1 (later called Defender) and other competitors were body on frame, or truck-based.
“The unibody was 400 pounds lighter than the competition,” said Chris Theodore, who briefly worked with Lunn at AMC and later became Chrysler’s vice president of platform engineering.
“The other key to the Cherokee was the four-door model,” Theodore told Automotive News. “Competitors quickly copied four doors when sales took off, but it took a long time for them to switch to unibody.”
The Cherokee was not the first time Lunn led a team that created a groundbreaking product. Nor would it be his last.
Roy C. Lunn was born in Richmond, England, in 1925 and earned degrees in mechanical and aeronautical engineering at Kingston Technical College. He served as a pilot in the Royal Air Force during World War II, then began his automotive career at AC Cars as an engineer in 1946. Lunn moved to Aston Martin and worked on the DB2 grand touring car, and then took a turn at British automaker Jowett. He joined Ford Motor Co. in 1953.
One of Lunn’s early projects at Ford of Britain was a stylish compact called the Anglia 105E. The car was such a huge sales success that it set in motion Ford’s climb in the 1960s to unseat the struggling British Motor Corp. as England’s highest volume automaker.
The Anglia’s success was noticed in Dearborn, and Lunn was offered a management job in product development. From 1958-69 Lunn headed Ford’s advanced vehicle department and advanced concept group. One of the cars Lunn’s team worked on was the midengine Mustang I concept car, which debuted in 1962 and morphed into the Falcon-based Mustang in 1964. He also worked on concept trucks and the GT40, which was the culmination of Ford’s total performance drive of the mid-to-late 1960s. From 1966-69 Ford won the 24 Hours of Le Mans, defeating Ferrari, a personal goal of longtime Chairman and CEO Henry Ford II.
“The team that put together the Ford GT of today was inspired by the work of Roy and his team and we will be forever grateful for the work they started,” Raj Nair, Ford’s president of North America, said in a statement. “His legacy as the godfather of the original Ford GT40 was well known throughout the company, and he helped bring Ford a performance car that is just as legendary today as it was in the 1960s.”
With Ford’s racing activities winding down, Lunn took a job as vice president of engineering at Kar-Kraft, a Detroit outfit that oversaw production of the thundering Boss 429 Mustang.
In 1971, American Motors came calling and offered Lunn the post of technical director for Jeep — then a niche brand of enthusiast-driven, off-road vehicles.
Another project that Lunn was instrumental in creating, said Schorr, was the AMC Eagle wagon, the first modern American all-wheel-drive car and the precursor to today’s awd crossovers.
Lunn was inducted into the Automotive Hall of Fame in 2016.
Lunn joined AM General in 1985 as vice president of engineering to steer the HUMVEE military compliance program at the U.S. Department of Defense.
Even after Lunn retired, he never stopped working, Schorr said.
He designed and created furniture, built a wooden dingy and, at the time of his death, was mentoring engineering students at the University of California at Santa Barbara.
Before Lunn quit driving in 2015, he regularly drove a bright-red, four-door Jeep Cherokee XJ. Said Schorr: “He just loved his Jeep and wouldn’t give it up until he had to surrender his license.”
Schorr said Lunn suffered a stroke in late July and never regained consciousness.
Fuente: Automotive News