When you design a new vehicle from scratch, it’s easy to think big – push the limits of performance and fuel efficiency, explore radical designs that will excite and challenge buyers, integrate every electronic bell and whistle you can imagine.
However, when you’re working on vehicles with decades of history, loyal fans, and billions of dollars invested in manufacturing capacity, things get much tougher. On one hand, staying competitive means changing as much as possible. On the other, change too much, and you risk customer loyalty and corporate profits.
That’s been the challenge for Fiat Chrysler Automobiles’ (FCA’s) most important vehicles. In the past 18 months, the automaker has massively reimagined its iconic Jeep Wrangler, a vehicle with more than 75 years of heritage, and its Ram 1500 pickup, the best-selling model for the entire company. The new vehicles are lighter and more efficient than the models they replace, yet they retain the elements needed to keep buyers, corporate cost managers, and regulators happy.
“We are the stewards of a brand that owes everything to the enthusiasm of the Jeep community,” says Mike Manley, FCA’s recently named CEO and the former head of the Jeep and Ram brands. “Our job is to listen and deliver on what they so clearly want.”
Both vehicles show what manufacturing technology is enabling
2018 Jeep Wrangler
Making a pickup or off-road vehicle that gets 30mpg is deceptively easy. Throw in a 66hp, 1.3L, 4-cylinder engine; replace heavy-duty frame components with less-capable ones
But it wasn’t a Jeep.
It couldn’t splash through steams, power up hills, or ignore major obstacles in its path. Every component that makes a Jeep Wrangler heavy is what makes it the most dominant off-road vehicle in U.S. history. So, when FCA officials tasked the Wrangler design team with lowering weight and improving fuel efficiency for the 2018 Wrangler, the simple, easy options were off the table.
“The all-new Wrangler is instantly recognizable as a Jeep, staying true to the original, yet it is better in every way – delivering even more rugged capability, more ride comfort, more fuel efficiency courtesy of several advanced powertrain options, more interior comfort, more safety, and more technology,” Manley says.
Designers working on the 2018 model knew they couldn’t lower power, remove rugged-but-heavy suspension components, or eliminate four-wheel drive systems. The new Wrangler would need a stiff, rugged, steel frame under its body.
Some clever engine technologies (a turbocharged 4-cylinder option or a V-6 with start-stop technology that shuts off the engine at stop lights to conserve gas) and a more-efficient transmission would help, but those improvements wouldn’t offer the efficiencies needed to comply with future fuel-economy regulations or help the vehicle’s popularity grow in countries with high fuel costs.
Jeff Gale, Jeep’s chief exterior designer, says designers opted to replace steel doors, liftgates, fenders, and hoods with aluminum, shaving about 200 lb from each vehicle. The goal was better fuel economy, but other benefits flowed from
“With the lighter panels, we only need one bolt per hinge on the doors and liftgate,” Gale says. “So, it’s much easier to remove those for off-roading. We only needed four bolts to lower the windscreen from the safety frame.”
2019 Ram 1500
While pickup drivers don’t want to waste gasoline, fuel economy tends to be a secondary concern to performance. So, improved efficiency for FCA’s best-selling vehicle couldn’t come at the expense of power, towing capacity, or seating space. As with the Jeep, strategic use of advanced materials lowered weight by 225 lb compared to the outgoing model.
The Ram’s chassis is 120 lb lighter than the outgoing model – 100 lb from the frame, 20 lb from the suspension. Nearly all the frame’s material (98%) is high-strength steel. Automakers increase their use of stronger, stiffer steel each year to cut weight by replacing thicker components with hard-to-cut, and hard-to-form, thin-walled replacements.
Ram 1500 hoods have been aluminum for several years, but for the 2019 model, the company also used the lightweight metal for the tailgate, engine mounts, front-axle center section, front-suspension
Mixing metals lowers weight, but the process requires upgraded paint pre-treatment systems, investments in joining systems, and higher material costs. Joe Dehner, head of Ram and Mopar design at FCA, says those changes were needed to meet the company’s “no sacrifices” goal for the truck.
“Cutting weight and boosting efficiency
To further cut weight, engineers replaced steel upper front suspension control arms (integrated with a steel structure) and air-dam structures with composite versions.
One issue designers ran into during the redesign, he says, was increased noise in the truck’s cabin when equipped with the company’s popular 5.7L Hemi V-8 engine. Adding insulation or thicker materials deadens noise but adds weight. Instead, the team added electronically controlled, side-frame-mounted, active tuned-mass modules (