Higher reliability score
M104 BEST 85/100
+30 points over M166
0 / 100
CAUTION M166 Mercedes-Benz
0 / 100
BEST M104 Mercedes-Benz

Specifications

M166
M104
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
CAUTION
BEST
Reliability
55
85
Years
1997--2004
1990--1997
Displacement
1598 cc
3199 cc
Layout
I4
I6
Type
Petrol Na
Petrol Na
Power
82--102 hp
193--231 hp
Known Issues
1
1
Total Risk Cost
€500--€1,200
€500--€2,000

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."

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

M166 1

▲ HIGH
Head gasket failure €500--€1,200 60,000 km--120,000 km

M104 1

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

Models

Full M166 Report Full M104 Report