Keller Rohrback, a law firm out of Seattle, is gathering Jeep Wrangler and Grand Cherokee 4xe owners for a possible class-action lawsuit. A call-to-action post on the business’ website claims Jeep misled buyers of the plug-in hybrid off-roaders by claiming they can operate in electric-only mode, though Keller Rohrback claims that’s not always true. It’s supposedly due to the vehicles’ fuel and oil refresh mode (FORM) that keeps the internal combustion engine constantly engaged in winter temperatures.
The Drive has reached out to Jeep for comment but hasn’t yet heard back. The law firm cites allegations from owners who say their Jeeps can’t achieve the 21 to 25 miles of battery-only range claimed by the manufacturer “for months at a time during cold weather.” As such, they say the premium they paid for these models was needless, pointing the finger at Jeep for false advertising.
FORM cycles are used in hybrid models to keep gaskets and seals warm and expanded, preventing gasoline from mixing with the oil. It does this by firing the internal combustion engine for short bursts while it reaches operating temperatures. It’s normal for some gas and oil to mix in internal combustion engines, but the heat from regular operation evaporates the negligible amount of gas. That’s not always the case in plug-in hybrids, which may run for extended periods of time without engaging the combustion engine. Some Jeep 4xe owners claim their rigs have the opposite problem.
A thread on 4xe Forums from February 2022 details the alleged issue at hand, as well as a few hopeful solutions. Some owners have blocked off their front grille entirely in order to retain heat while driving in winter; in fact, Mopar sells a specialized cover for the Wrangler. User 4xeveryday says the key is to maintain oil temperatures of at least 192 degrees Fahrenheit for 20 minutes or more, which apparently hasn’t been possible for some in northern states without making modifications.
The Wrangler 4xe was the United States’ best-selling plug-in hybrid in 2022, making up nearly a quarter of all Wrangler sales. Its turbocharged 2.0-liter engine is aided by a small battery pack and electric motor to produce 375 horsepower and 470 pound-feet of torque combined. It’s far from the most efficient PHEV out there, achieving 20 mpg according to the EPA, but hey—people don’t buy Jeeps for fuel economy.
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