Mercedes-Benz 285ci Specs: 92.9 x 86 mm

Mercedes-Benz 285ci specs: 92.9 x 86 mm (3.6575 x 3.3858 in) bore and stroke. Displacement, compression and factory ratings, plus rod ratio.

At a glance

Displacement	285 ci
Cylinders	8
Bore	3.658"
Stroke	3.386"
Compression	10.5:1
Advertised power	402 hp
Years	2012–2020

This engine

Engine	Displacement	Bore × Stroke	CR	HP
M278	285 ci	3.6575" × 3.3858"	10.5:1	402

Factory cars with a Mercedes-Benz 285ci

• Mercedes-Benz E-Class: 2012, M278, 402 hp; 2013, M278, 402 hp; 2014, M278, 402 hp; 2015, M278, 402 hp; 2016, M278, 402 hp; 2017, M278, 402 hp
• Mercedes-Benz S-Class: 2012, M278; 2013, M278; 2014, M278; 2015, M278; 2016, M278; 2017, M278
• Mercedes-Benz SL: 2013, M278; 2014, M278; 2015, M278; 2016, M278; 2017, M278; 2018, M278; 2019, M278; 2020, M278

What varies across the family

This family is represented by a single engine in the database: 285 ci, 8 cylinders, a 3.6575" × 3.3858" bore and stroke.

All are oversquare — bore larger than stroke, which favours revs over low-end torque.

Each engine page carries rod ratio, mean piston speed, bore/stroke character and cylinder head specs where published, and links into the calculators with its dimensions already filled in.

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