M278 vs M104

Side-by-side reliability comparison

Higher reliability score
M104 BEST 85/100
+23 points over M278
0 / 100
CAUTION M278 Mercedes-Benz
0 / 100
BEST M104 Mercedes-Benz

Specifications

M278
M104
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
CAUTION
BEST
Reliability
62
85
Years
2010--2018
1990--1997
Displacement
4663 cc
3199 cc
Layout
V8
I6
Type
Petrol Turbo
Petrol Na
Power
408--455 hp
193--231 hp
Known Issues
2
1
Total Risk Cost
€2,500--€9,500
€500--€2,000

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."

M104

"W124/R129/W140 inline-6. One of Mercedes' most reliable engines. Bulletproof bottom end. Wiring harness biodegrades (uses soy-based insulation). Head gasket solid. 400k+ km possible."

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

M104 1

▲ HIGH
Wiring harness biodegradation €500--€2,000 100,000 km--200,000 km

Models

M278 2

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

M104 0

No models listed.

Full M278 Report Full M104 Report