OM668 vs OM654
Side-by-side reliability comparison
Higher reliability score
OM654
BEST
85/100
+27 points over OM668
0
/ 100
CAUTION
OM668
Mercedes-Benz
0
/ 100
BEST
OM654
Mercedes-Benz
Specifications
OM668
OM654
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
CAUTION
BEST
Reliability
58
85
Years
1998--2004
2016--present
Displacement
1689 cc
1950 cc
Layout
I4
I4
Type
Diesel
Diesel
Power
75--95 hp
150--245 hp
Known Issues
2
2
Total Risk Cost
€800--€2,000
€500--€1,500
Character
OM668
"W168 A-Class. Same era as M166 petrol. Injector issues. Head gasket concerns. Turbo failure on higher-output version. Not Mercedes' best diesel. Better alternatives exist."
OM654
"Best modern MB diesel. Aluminium block, low friction. Long-distance champion."
Issues Comparison
OM668 2
▲ HIGH
Head gasket failure
● MODERATE
Injector 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