M166 vs OM656

Side-by-side reliability comparison

Higher reliability score
OM656 BUY 82/100
+27 points over M166
0 / 100
CAUTION M166 Mercedes-Benz
0 / 100
BUY OM656 Mercedes-Benz

Specifications

M166
OM656
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
CAUTION
BUY
Reliability
55
82
Years
1997--2004
2017--present
Displacement
1598 cc
2999 cc
Layout
I4
I6
Type
Petrol Na
Diesel
Power
82--102 hp
243--330 hp
Known Issues
1
2
Total Risk Cost
€500--€1,200
€500--€2,000

Character

M166

"W168 A-Class. Infamous moose test rollover era. Engine itself is adequate but head gasket failures common. Oil leaks. Not a strong Mercedes engine. Better to look at M271 successor."

OM656

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

Issues Comparison

M166 1

▲ HIGH
Head gasket failure €500--€1,200 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

M166 3

A-Class W168 1997--2004 A-Class W168 1997--2004 A-Class W169 2004--2009

OM656 3

E 400d W213 2016--2024 Sedan GLE 350d W166 2015--2019 SUV S 350d W222 2013--2020 Sedan
Full M166 Report Full OM656 Report