The electrified model combines a newly developed turbocharged 3.0-litre six-cylinder engine with an integrated starter, which is part of Mercedes’ 48V electric architecture.
The powertrain is shared with the CLS 53 and produces 429bhp and 295lb ft of torque, with an additional boost of 21bhp and 184lb ft when the starter motor provides temporary shove. The E53’s new 0-62mph time is 4.5sec, two-tenths quicker than the E43, while its top speed is limited to 155mph. An optional AMG Driver’s Package increases the top speed to 168mph.
It's on sale now, priced from £61,835 for the saloon. This is an increase of £15,290 over the E43 that comes largely thanks to the new car's more complex powertrain. The new E53 estate makes the same jump to start at £63,835.
AMG won’t be producing a new E43 because that car’s V6 engine is gradually being phased out of the range. Although it’s currently still available in the C43, where it offers 362bhp, that engine will eventually be superseded by the newer straight-six.
The fastest E-Class, the E63, retains its 563bhp twin-turbocharged 4.0-litre V8 engine. The S variant’s 612bhp from the same engine also remains.
Beneath the AMG models, Mercedes has replaced the V6 diesel of the E400d, its top oil-burning E-Class, with a straight-six. The new unit offers 335bhp and 516lb ft, increases of 7bhp and 162lb ft respectively. Like the rest of the line-up, the engine is certified to the latest Euro 6d Temp emissions standards.
Changes for the wider E-Class range include fitment of Mercedes’ latest steering wheel design, as well as a more advanced Active Steering Assist system, which can adjust the car’s speed to more comfortably take corners.
UK prices for the wider E-Class range will be announced later this week. A small rise on the current E-Class's starting price of £38,210 is expected.