Stellantis, the automaker conglomerate with a sprawling portfolio of brands, will focus most of its investments for the U.S. market into its Jeep and Ram divisions while introducing more cars under $40,000, according to a turnaround plan outlined for investors Thursday.

Jeep and Ram are said to be two of Stellantis’s “four key brands,” with the other two being its mainstream European makes, Peugeot and Fiat. Under Chief Executive Antonio Filosa’s $70 billion revival plan, the four will receive 70% of the company’s product investments.

Those include plans for more-affordable new cars, a problem that has plagued Stellantis’s U.S. dealers in particular. In North America, Stellantis plans to grab a bigger share of the market with 11 all-new vehicles, including seven “under the $40,000 range” and two “under $30,000.”

Under the plan, the Chrysler brand—a storied nameplate currently down to selling only one minivan—will receive three new compact SUVs, at least one of which will start under $30,000....