M156 vs OM656

Side-by-side reliability comparison

Higher reliability score
OM656 BUY 82/100
+22 points over M156
0 / 100
CAUTION M156 Mercedes-Benz
0 / 100
BUY OM656 Mercedes-Benz

Specifications

M156
OM656
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
CAUTION
BUY
Reliability
60
82
Years
2006--2015
2017--present
Displacement
6208 cc
2999 cc
Layout
V8
I6
Type
Petrol Na
Diesel
Power
457--514 hp
243--330 hp
Known Issues
2
2
Total Risk Cost
€2,500--€7,500
€500--€2,000

Character

M156

"C63/E63/S63 W204/W212/W221. Head bolt failure on early units (2007-2008). Intake manifold swirl flap. Cam adjuster bolts. Incredible NA V8 sound. Later production much improved."

OM656

"Flagship modern MB diesel. Inline-6 smoothness returns. MHEV. GLE/GLS/S-Class. Excellent highway. Early data strong."

Issues Comparison

M156 2

◆ CRITICAL
Head bolt failure (2007-2008) €2,000--€6,000 40,000 km--100,000 km
▲ HIGH
Intake manifold swirl flap €500--€1,500 60,000 km--120,000 km

OM656 2

● MODERATE
DPF + EGR — diesel city driving concern €400--€1,200 60,000 km--120,000 km
○ MINOR
AdBlue / SCR system consumption and faults €100--€800 30,000 km--∞

Models

M156 3

CLK W209 2006--2009 E-Class W211 2006--2009 C-Class W204 2008--2014

OM656 3

E 400d W213 2016--2024 Sedan GLE 350d W166 2015--2019 SUV S 350d W222 2013--2020 Sedan
Full M156 Report Full OM656 Report