M278 vs OM606

Side-by-side reliability comparison

Higher reliability score
OM606 BEST 96/100
+34 points over M278
0 / 100
CAUTION M278 Mercedes-Benz
0 / 100
BEST OM606 Mercedes-Benz

Specifications

M278
OM606
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
CAUTION
BEST
Reliability
62
96
Years
2010--2018
1993--2001
Displacement
4663 cc
2996 cc
Layout
V8
I6
Type
Petrol Turbo
Diesel
Power
408--455 hp
134--174 hp
Known Issues
2
2
Total Risk Cost
€2,500--€9,500
€280--€700

Character

M278

"W222 S500, W166 GLE500, W212 E550. Hot-V twin-turbo. Timing chain guides. Turbo oil line leaks. Expensive timing chain job (engine-out in some models). Powerful but costly to own."

OM606

"Legendary. 500k+ miles documented. Tunable to 500hp. One of most reliable engines ever."

Issues Comparison

M278 2

◆ CRITICAL
Timing chain guide failure €2,000--€8,000 80,000 km--150,000 km
▲ HIGH
Turbo oil line leak €500--€1,500 60,000 km--120,000 km

OM606 2

○ MINOR
Glow plug failure (only meaningful issue) €80--€200 80,000 km--∞
○ MINOR
Injection pump seal wear (age-related) €200--€500 200,000 km--∞

Models

M278 2

SL R231 2012--2018 S-Class W222 2013--2017

OM606 2

300D W124 1993--1997 Sedan E 300D W210 1995--2003 Sedan
Full M278 Report Full OM606 Report