Higher reliability score
OM656 BUY 82/100
+10 points over OM651 (late)
0 / 100
ACCEPTABLE OM651 (late) Mercedes-Benz
0 / 100
BUY OM656 Mercedes-Benz

Specifications

OM651 (late)
OM656
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
ACCEPTABLE
BUY
Reliability
72
82
Years
2014--2020
2017--present
Displacement
2143 cc
2999 cc
Layout
I4
I6
Type
Diesel
Diesel
Power
136--204 hp
243--330 hp
Known Issues
2
2
Total Risk Cost
€800--€2,200
€500--€2,000

Character

OM651 (late)

"Post-2014: updated injectors + pump. Much improved. Highway excellent."

OM656

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

Issues Comparison

OM651 (late) 2

▲ HIGH
DPF blockage — city driving concern €500--€1,500 60,000 km--120,000 km
● MODERATE
EGR valve fouling (post-2014) €300--€700 80,000 km--150,000 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

Full OM651 (late) Report Full OM656 Report