Engine, 0-60mph and gearbox
The range kicks off with the 300d, which is powered by a 2.0-litre four-cylinder diesel engine. In our tests, it managed a very respectable 0-60mph time of 7.7sec, so offers very similar performance to the Audi Q7 45 TDI.
The only other engine we've tried so far is the 3.0-litre six-cylinder petrol (badged as the GLE 450). This is a 'mild hybrid', so there's a small amount of electrical assistance to give it some extra pull at low revs. It feels significantly more sprightly than the 300d and its claimed 0-62mph time drops to just 5.7sec.
There are also a couple of six-cylinder diesels (the 350d and 400d). We haven't tried either engine in the GLE, but given how brilliant they are in other Mercedes models, we suspect they might be the engines of choice.
If you plan to tow heavy loads, it's worth noting that, in its standard form, the GLE can pull just 2700kg – significantly less than the Audi Q7 or Land Rover Discovery. The optional Towing Package makes the GLE a match for those rivals but isn't available on the entry-level 300d.
Suspension and ride comfort
Two suspension set-ups are available on the GLE, but the decision is made for you depending on your engine choice. In short, the entry-level 300d comes with conventional steel springs, whereas plusher air suspension is fitted to the more expensive models.
We're yet to try the steel springs, but cars with air suspension (Airmatic in Mercedes speak) are impressive. The GLE is certainly more comfortable than a Discovery on typical town roads, for example, and is really quite cosseting on the motorway. However, the car's slightly wallowy nature means you notice your torso and head bouncing and swaying around quite a bit along uneven country roads.
For the most comfortable ride in the luxury SUV class, look to the Audi Q7.
Well, around town, the steering is very light, making tight manoeuvres easy, but it’s somewhat numb and vague at higher speeds.
Carry some speed into a corner and there’s a fair bit of body roll as well. Admittedly, the GLE doesn't sway around as dramatically as the Discovery, but neither is it as composed and confidence-inspiring through bends as the Q7 or BMW X5.
Noise and vibration
Other than a bit of wind noise at higher speeds, the GLE's interior is really peaceful – you'll never need to raise your voice to chat with passengers. In this class, only the Q7 and more expensive BMW X7 are quieter options.
The engine in the GLE 450 is particularly hushed; the 300d diesel is noticeably noisier, but it's still a lot smoother and quieter than the equivalent (SD4) engine in the rival Discovery.
All GLEs have a nine-speed automatic gearbox as standard that is both more responsive and smoother than the equivalent gearbox in an Audi Q7.