M166 vs OM654
Side-by-side reliability comparison
Higher reliability score
OM654
BEST
85/100
+30 points over M166
0
/ 100
CAUTION
M166
Mercedes-Benz
0
/ 100
BEST
OM654
Mercedes-Benz
Specifications
M166
OM654
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
CAUTION
BEST
Reliability
55
85
Years
1997--2004
2016--present
Displacement
1598 cc
1950 cc
Layout
I4
I4
Type
Petrol Na
Diesel
Power
82--102 hp
150--245 hp
Known Issues
1
2
Total Risk Cost
€500--€1,200
€500--€1,500
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."
OM654
"Best modern MB diesel. Aluminium block, low friction. Long-distance champion."
Issues Comparison
M166 1
▲ HIGH
Head gasket failure
OM654 2
○ MINOR
DPF — better than older MB diesels but still diesel
○ MINOR
Minor EGR fouling (best-in-class but not immune)
Models
OM654 47
B-Class
A-Class
GLA
A-Class
C-Class
C-Class
GLC
E-Class
GLC
E-Class
GLE
E-Class
C-Class
C-Class
GLC
GLC
E-Class
C-Class
E-Class
GLC
C-Class
C-Class
GLC
E-Class
CLA
A-Class
CLA
B-Class
GLA
GLA
A-Class
E-Class
S-Class
GLE
E-Class
G-Class
E-Class
G-Class
G-Class
S-Class
S-Class
S-Class
GLE
S-Class
C 220d Wagon
E 220d Wagon
GLC 220d Coupe