2024 Mercedes-Benz GLE450e 4Matic First Test Review: The Practice EV

As we noted in our First Drive review, this example of the "E-Class of Benz SUVs" blends turbo inline six-cylinder performance with better-than-turbo inline four-cylinder economy for a $2,000 premium over the gas GLE450. We all know prospective EV buyers will look for a long-range fully electric SUV with a 100-ish-kWh battery pack, 80 percent of which will only be needed a handful of times per year. Here, instead of carrying 1,000 pounds of surplus battery, you're lugging perhaps 700 to 800 pounds' worth of just-in-case engine, transmission, fuel, and exhaust systems. How efficient is it? Sadly, the EPA isn't expected to release official economy and range numbers until closer to this Mercedes' official on-sale date this fall, but that big battery will likely grant mpg-e numbers in the 50s.

Maybe, for folks who aren't already spoiled by the right-now acceleration of an EV, because asking for that kind of acceleration will always fire the gas engine—perfect for weekend fun trips. The interior quietness, "refuel-at-home" convenience, and DC fast charging will impress your friends (the charging rate ain't great, but the battery's small, so it fills relatively quickly). Then again, there's no one-pedal driving mode—the shift paddles amp up the regen braking somewhat—even if the car will automatically increase regenerative braking when closing on a slower-moving vehicle in EV mode.

How quick is the Mercedes-Benz GLE450e? This plug-in hybrid's GLE450e moniker promises—and delivers—gas six-cylinder performance by teaming a variant of the GLE350's 2.0-liter turbo four good for 248 hp and 295 lb-ft with a 134-hp/325-lb-ft electric motor wedged in where a transmission's torque converter would otherwise be.

Boasting a combined 381 hp and 479 lb-ft, the hybrid's rated output is just enough more than the gas GLE450 model's (362 hp/369 lb-ft) to cope with the roughly 750-pound weight difference. Indeed, the traces of the two GLE450s' acceleration curves are very close together, with the pricier hybrid slightly ahead. Zero to 60 mph happens in 5.5 seconds en route to a 14.0-second, 98.2-mph quarter mile in the PHEV, as compared with 5.6 and 14.2 at 97.4 mph in the gasser.

The GLE450e is a lousy EV in terms of electric performance. By including the gas-powered GLE350's acceleration on the same graph, we can guesstimate the performance in electric mode as roughly a GLE200. Although its weight-to-power ratio nearly triples from 15.5 pounds/horsepower in hybrid mode to 44.2 in EV mode, the weight-to-torque value is only 47 percent worse than the gas model's. This helps keep acceleration performance reasonable at 15.0 seconds to 60 mph on the way to a 19.9-second/67.3-mph quarter-mile time. That seems like forever when waiting to trip quarter-mile lights, but when you're not drag racing (or running super late for an appointment), that performance is entirely adequate. We've yet to test rival BMW's X5 xDrive45e. It boasts a bigger 24-kWh battery good for 31 miles of range, a weaker 111-hp/77-lb-ft motor, and a curb weight about 300 pounds less.

We discovered by monitoring one of about a gazillion possible display screens that a throttle angle of 65 percent or more triggers the GLE450e's gas engine—that's well shy of the 95 or so percent kickdown switch detent some automakers use to fire the engine, such as Alfa Romeo in the Tonale PHEV.

The GLE450e starts up in electric mode by default whenever the battery state of charge permits. Not every PHEV offers this option, and those that don't often have grossly underpowered electric motors providing acceleration that would try Job's patience. In our time with the 450e we only lit the engine a handful of times in normal driving, generally when merging into heavy, fast-moving traffic. And the screens offer lots of EV-type functionality, including charging-station overlay on maps, Mercedes Me charging—even a renewable energy program.

Weighing in at 5,924 pounds, the Mercedes-Benz GLE450e never feels nimble, and all that added mass exacts some handling-performance penalties. Braking from 60 mph takes 5 to 8 feet longer than in the gas GLE450 at 123 feet, but stops were impressively consistent, with four varying by within 4 feet and none showing appreciable brake dive or fade. Similarly, lateral grip drops from 0.83 to 0.80 on identical Pirelli Scorpion Zero tires, while figure-eight performance slips 0.4 second and 0.02 average g. Please note that the GLE450e still outhandles the GLE350 (130-foot braking, 0.78 g, 28.2 seconds at 0.62 g), largely due to the 350's same-size but less aggressive Michelin Primacy Tour tires.

It's incredibly rare to find DC fast-charging capability on a PHEV. The Mitsubishi Outlander PHEV's CHAdeMO plug provides DC, and the late Honda Clarity PHEV offered fast-charging via the more common CCS standard. The 23.3-kWh battery (big for a PHEV) is said to need only 20 minutes to go from 20 to 80 percent charge using the big plug at its maximum rate of 60 kW (please don't hog the 350-kW plugs!). Recharging via the typical level-2 home or office charger takes 2.8 hours at 11 kW, so this capability greatly increases the electric-only distance an owner can expeditiously cover in a normal day.

On our early drive of prototype GLE450e vehicles we complained of nonlinear brake-pedal feel, raucous engine noise, and rough transmission shifts, all of which seem to have been addressed. And yes, this is a serene cabin in which to commute, replete with massaging seats, fragrance dispenser, and myriad other sybaritic accoutrement designed to cater to varying caprices. Maybe spend some time trying the user interface before buying, as it annoys many staffers. One big gripe: It's tough to access the cupholders without brushing the adjacent touchpad and altering what's on the screen.

Middle Americans looking for a practice EV should absolutely consider it. Its ability to operate with the engine remaining off is admirable because, as we've repeatedly noted, buying a PHEV and never plugging it in, or driving it in a way that fires the engine multiple times on a given journey can be way worse for the environment than simply buying a clean combustion SUV or a small-battery hybrid. The only other reason folks typically consider PHEVs (for the tax dodge) doesn't apply to the GLE450e because its base price exceeds $55,000. Just remember to go easy on the gas pedal after you trade this Mercedes-Benz GLE450e in on that fully electric Audi Q8 E-Tron, GMC Hummer EV SUV, or Rivian R1S.