2020 Mercedes GLE450 Review

If you pop the hood of the new GLE, Mercedes’ mid-sized SUV, you will see something no one has seen under the hood of a new Mercedes in more than 20 years:

An in-line six.

It’s an inherently balanced so inherently smoother form of six than a V6. And it has a number of other advantages as well, including fewer parts and easier access to them.

Some of the most iconic Benzes ever made—like the 300 SL Gullwing coupe of the ‘50s—were powered by inline sixes.

And now, you can own a new Mercedes powered by one.

You will also not see something else under the GLE450’s hood:

Belt-driven accessories such as a water pump, alternator, power steering pump and air conditioning compressor. The accessories are there.

Just not the belt.

Not even a single serpentine one. The GLE450’s accessories are all driven electrically to take the load off the engine as well as to eliminate the need for periodic belt changes.

And that’s not all.

What It Is

The GLE is the successor to the hugely successful M-class SUV of the late ‘90s and early 2000s, which combined formidable off-road capability with on-road civility.

It competes with models like the BMW X5 and Range Rover Sport.

Like them, it comes standard with two rows but also offers an available third row.

Also like them, it is a real-deal SUV that can tow several thousand pounds more than a light-duty crossover SUV (up to 7,700 lbs.) and has the capability to traverse rough terrain without behaving like a farm implement when the terrain isn’t rough.

Base price is $53,700 for the rear-wheel-drive GLE350, which comes standard with a 2.0 liter turbocharged four cylinder engine. Mercedes’ 4Matic all-wheel-drive system, which can route 100 percent of the engine’s power to either the rear or the front wheels is available optionally.

So equipped, the MSRP is $56,200.

The GLE450 comes standard with Mercedes’ new 3.0 liter in-line six supplemented by a 48 volt mild-hybrid system Mercedes calls EQ Boost. It features a high-torque electric starter/generator that is used to seamlessly cycle the gas engine off and on, both when the GLE isn’t moving (as when waiting at a red light) as well as when it is (as when coasting) in order to save fuel and reduce emissions.

It stickers for $61,150 and comes standard with the 4Matic AWD system.

What’s New

The redesigned GLE is a few inches longer than before—which makes possible the availability of third-row seating for the first time in this model. The old M-Class (as well as the previous GLE) was a five-seater only.

Also new are both of the GLE’s standard and available engines well as the interior, the centerpiece of which is a new dual 12.3 inch LCD touchscreen array and voice/gesture interface (MBUX) that learns your preferences and obeys both oral commands and gestures, such as hand and arm movements. No need to touch anything to engage the massaging seats, make a call, change the interior mood lighting or adjust the stereo’s settings.

There is also a new E-Active Body Control adjustable suspension system that can fine-tune damping forces at each of the four wheels individually—a feature unique to the GLE. The system can also get you unstuck when off-roading by rocking each corner up and down until traction is recovered.

And there is the unique-to-the GLE450 48 volt electric system, which among other things solves the ASS problem (more on this below).

What’s Good

More power—better mileage.

More room.

Borderline miraculous tech.

What’s Not So Good

Center console cubby is small.

MBUX system can’t whip up a BLT, yet.

Under The Hood

The base GL350 is powered by a 2.0 liter turbocharged four that makes 255 horsepower; this engine is paired with a nine-speed automatic and either rear-drive or 4Matic all-wheel-drive.

The GL450 comes with the much stronger 3.0 liter in-line six, supplemented by the high-torque starter/motor and 48 volt mild hybrid system, also paired with the nine-speed transmission and standard 4Matic.

Total output is 362 horsepower—21 of them coming from the electric motor/starter—which is how you get this beefy SUV to 60 in 5.5 seconds.

That’s about two seconds quicker than the GLE350 but without the usual downturn in MPGs.

The stronger, much quicker GLE450 rates 19 city, 24 highway vs. 19 city for the GLE350.

You get to have your cake and eat it, too.

You also don’t get something else.

The paint-shaker effects of ASS.

Automated Stop/Start is standard in the GLE as it is becoming standard in pretty much every new car, as the car companies struggle to meet federal Corporate Average Fuel Economy edicts. One way to burn less gas is to not burn any by turning the engine off whenever feasible.

That’s what ASS is all about.

But the engine has to be turned on again in order to get the vehicle moving again. All of this stopping and restarting is hard on the battery. The 12V battery wasn’t designed for this kind of duty.

12V batteries were designed (50-plus years ago) to start the engine, which then continued running usually until you got where you were going. Maybe with one or two stops (and starts) in between.

Not a dozen or more stop/start cycles every time you went for a drive.

ASS is very hard on 12V batteries. It is also hard on your peace. All that stop/starting begins to wear on you chiefly because it’s obviously happening. You can feel (and hear) it happening at every traffic light.

Benz (and others) solve both problems—the necessity of CAFE compliance and the importance of not annoying buyers with operational unpleasantness—by quadrupling the voltage and using super-fast integrated starter/motor/generators. The result is stopping and restarting you don’t notice.

You’ll also notice the AC stays on even when the engine is off because the AC compressor is electrically powered. And while you won’t notice it, the electrically powered water pump will keep the in-line six’s temperature even, even when the engine isn’t running.

In the GLE450, the 48V system also lets the engine “sail” during low-load coast/deceleration; these events are also unnoticeable — except via the fuel gauge.

This variant of ASS does save gas.

Not just the trivial 1-2 MPG difference you get with 12V ASS, which doesn’t compensate you, the owner, for the annoyance of all that noticeable stopping and starting and which also will probably cost you more in the long run, courtesy of reduced 12v battery life.

Here, ASS is worth a solid 5 MPG, maybe more.

It also helps you haul ass.

Remember: An additional 21 horsepower, plus the instant torque of the electric motor, which is why the new GLE450 with the 3.0 in-line six and EQ system, is also quicker than the 2019 GLE400 with the 3.0 V6 (by almost half a second to 60) while using less fuel.

It also tows more: 7,500 lbs. vs. 7,200 previously.

On The Road

Don’t miss the new six.

It is worth the extra cost but not because it gives you so much more power without noticeably more appetite vs. the standard 2.0 four. That’s a bonus. The real payoff is the jet engine smoothness of the in-line configuration and the 48V EQ system.

Only an electric car is smoother and that not by much. And electric motors don’t sound like an in-line six, which is a sound you don’t want to miss.

It is silent, until you ask it to sing.

Then it’s time to turn off the outstanding Burmester audio system and enjoy the mechanical opera.

Configure your theme from the touchscreen—will it be Adventure (off-road) or Experience (sport)? There are also Lounge (comfort), Efficiency, Trip and Standard themes—each of which when selected reconfigures a host of drivetrain parameters, including throttle sharpness, turbo boost ad transmission shift characteristics as well as the LCD dash display, which changes completely with each new theme.

Adventure theme, for example, replaces the speedo and tach with angles of approach and departure, compass and how the 4Motion system is distributing power to the wheels. You can toggle up or down the ride height. Gauge backlighting and cabin ambient lighting changes will also match the theme.

Experience changes the main cluster to red-orange backlit tach and speedo, with the secondary cluster displaying an array of performance-related data such as the engine’s real-time horsepower/torque output and “charge air” (turbo boost). Once again, the cabin mood lighting alters to complement this theme.

There are three more themes. You can also even create your own theme, if you want.

At first, it’s almost too much. But you soon learn where everything is as well as how to engage it, which Mercedes has made much easier and much safer via multiple redundancies. You can change themes or the radio station or the ambient interior lighting by using the trackpad on the center console. Or just tap the 12.3 LCD touch screen.

Or, just ask Mercedes.


The MBUX voice recognition system is perhaps the most sophisticated such system on the market. It isn’t just to make calls hands-free. It does almost everything hands-free.

Mercedes, please turn on the passenger seat massage.

It is done.

Mercedes, please change the interior lighting blue, the radio to Howard 100.

A pleasant female voice responds — and makes it so.

Very few of the creature features require a physical input from you.

Just ask.

Meanwhile, your passengers can text, even on a rutted, washboarded/swallow-you-whole gravel mountain road, doing 35-40 MPH and drifting a bit through the curves. The Benz’s E-Active Body Control suspension doesn’t merely “dampen” the irregularities; it disappears them.

Ask my buddy and his son. I took them both for a ride up a road that is so bad it requires crawling at 10-15 MPH or less in a pick-up truck, slowing to ease in and out of the gaping potholes—assuming you don’t want to blow out a shock absorber or drop a crown.

The Benz took this same road twice the speed while my buddy texted.

It has to be experienced to be believed.

On paved roads, the GLE imparts a feeling of invulnerable solidity.

And the thing will corner, too. It’s like barrel-rolling a 707. You don’t think it’s possible and probably not a good idea to try.

But then it does with the effortless grace of an F18 doing the same.

At The Curb

The previous GL, which did not offer a third row, was always at a disadvantage vs. rivals like the X5 and Range Rover Sport, which did offer this feature.

Now it’s a fair fight.

Unfair, actually. In the Benz’s favor.

It now has a roomier second row (40.9 inches, adjustable to 41.1) and has more total cargo room (80.3 cubic feet) with the seats down than rivals like the X5 and Range Rover Sport — and an available third row that rivals the Porsche Cayenne do not even offer.

All of this was accomplished by adding about four inches to the new GLE’s overall length (194.3 inches for the 2020 vs. 189.7 for the ’19 GLE). That’s still a relatively compact footprint, about the same as a current mid-sized sedan such as the current Toyota Camry, which is 192.7 inches long overall and which does not offer a third row.

So, the GLE is big — just not too big.

This is important on road (parking) and off (maneuvering).

The Benz also has clearance—probably close to nine inches when fully extended (Mercedes hadn’t disclosed the official numbers when this review was written in mid-March). So it can go places no Camry can, with several more people on board.

It also has stance.

Note the slightly inboard staggered (and huge) meats. The muscular stampings and athletic pleats — including the stamped dual hood pleats, suggesting the in-line six underneath.

You may also notice the 50 percent larger panorama sunroof, which makes surfing the new GLE even more fun. Dial up whatever tune seems appropriate on the Burmester, slide the panel open and let your passenger do their thing.

Or, close it up and find a nice place to park. Then turn on the massagers and have a nap. This SUV is more comfortable than most people’s homes. And even if your home compares, you won’t miss it as much when you’re in the GLE.

The Rest

The new in-line six isn’t just silky smooth. Not merely more powerful than the V6 it replaces.

It is also simpler.

One cylinder head rather than two. One exhaust manifold. A single camshaft drive. And, no drive belts. This should reduce lifetime maintenance costs while the 48 volt mild-hybrid system will reduce fueling costs vs. a similarly powerful V6 without EQ Boost.

The new GLE is also cheaper than the previous GLE.

Well, it costs less (one should never use the word “cheap” in reference to a Benz) if you are willing to wait a little while for the GLE 350, which stickers for $2k less than last year’s GLE400.

It’s not available at Benz stores yet; Mercedes decided to start the show with the GLE450, to showcase the new six.

But you can get the rest of the new GLE, or most of it, at any rate, at a discounted price now.

An AMG version should be available by later this year or maybe next spring.

Is there anything not to like?

Well, the center console storage cubby is small and the MBUX system can’t materialize a delicious BLT on sourdough at your command.

Well, not yet.

The Bottom Line

The sci-fi writer Arthur C. Clarke once said that a technology sufficiently advanced is indistinguishable from magic.

The new GLE being Exhibit A.



*** Photo courtesy of Caricos

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