“It might not look like it, but it’s one of the most comprehensive facelifts we’ve ever undertaken,” says Michael Kelz, laying his hand on the bonnet of a lightly disguised Mercedes-Benz E-Class.
We’re standing in a layby not far from the pulsing neon heart of Las Vegas, where the project leader for the facelifted E-Class is taking a break from final validation testing to run through the changes made to the new car ahead of its upcoming Geneva motor show premiere.
This fifth-generation model is a well-known quantity, having first seen UK showrooms in 2017. But behind the mild disguise – hiding subtle styling tweaks that include a wider grille, reprofiled bumpers and a reshaped bootlid – lurks what Kelz describes as literally hundreds of detailed modifications.
"We’ve gone through every individual component and asked ourselves if it can be improved in one way or another," he says. "The biggest individual change is the upgrade to the electrical system. It allows us to add a number of new intelligent driver assistance systems with Level 2 capability and the latest in Car-to-X communications. It’s now more advanced than the S-Class in certain areas.”
The new electrical system also provides the basis for an upgrade of the MBUX user interface used by the E-Class, bringing the latest in touch, speech and gesture controls together with a “Hey Mercedes” prompt that allows you to control various functions via conversational-style speech.
As before, buyers get to choose between a pair of standard 10.3in or optional 12.3in digital displays for the instruments and infotainment functions.
Further changes brought to the interior of the facelifted E-Class include a new multi-function steering wheel, a new frameless rear-view mirror, revised trim applications and a touchpad infotainment controller - the latter of which comes at the expense of the rotary controller previously sited within the centre console between the front seats.
Starting with the 2020 model, Mercedes is introducing a new trim line hierarchy in which Avantgarde now becomes standard, with the more comprehensively equipped Executive and AMG lines as options.
The prototype we’ve been riding in over smooth surfaced roads through the desert regions of Nevada is the new four-wheel-drive E450 4Matic. It runs the turbocharged 3.0-litre six-cylinder M256 petrol engine with a 48-volt electrical system and integrated starter motor to provide it with mild hybrid properties.
With 362bhp and 369lb ft of torque plus 21bhp and 132lb ft from an electric motor, it boasts tremendously effective low to mid-range performance and outstanding refinement, promising to make it a very convincing alternative to the likes of the Audi A6 50 TFSI and BMW 540i xDrive.