Should I buy a 2018-2020 RR Sport with 35k miles for $50-55k or lease a new 2023 Jeep Grand Cherokee?

It’ll certainly run the engine most of the time once the plug in power is defeated, but not while stopped, going downhill, or much of the time in stop-and-go, or going slow speeds. Just like a normal hybrid. It’s definitely a heavy vehicle not built for efficiency, explaining why my Pacifica PHEV easily goes 30 miles all-electric and then gets 32 MPG on gas with much the same basic components.