Mercury 40hp FourStroke EFI vs Johnson 40hp (4-Stroke)
40hp FourStroke EFI
40hp (4-Stroke)
| Spec | Mercury 40hp FourStroke EFI | Johnson 40hp (4-Stroke) |
|---|---|---|
| Power & Performance | ||
| Horsepower | 40 HP | 40 HP |
| Displacement | 747 cc | 815 cc ← |
| Configuration | 3 Cyl / Inline | 3 Cyl / Inline |
| Weights & Dimensions | ||
| Dry Weight | 93 kg (205 lbs) ← | 109 kg (240 lbs) |
| Mechanical & Electrical | ||
| Gear Ratio | 2.00:1 | 2.27:1 |
| Alternator | 226 W ← | 216 W |
| Fuel Delivery | EFI | EFI |
| Maintenance | ||
| Spark Plug | NGK RA8HC | NGK DCPR7E |
| Engine Oil | Mercury FourStroke Oil 10W-30 | 10W-40 FC-W |
Technical Comparison Analysis
Power & Displacement
Comparing the Mercury 40hp FourStroke EFI and Johnson 40hp (4-Stroke) shows a displacement difference of 68cc. The Johnson features a larger 815cc block, which typically provides superior low-end torque and better hole-shot performance when pushing heavy loads or reaching planning speeds.
Weight & Rigging
In terms of transom weight, the Mercury is the lighter option at 93kg, offering a weight saving of 16kg over its competitor. This weight reduction is critical for smaller hulls or boats with limited transom capacity where every kilogram affects the center of gravity and drainage efficiency.
Electrical & Features
For boats equipped with modern electronics, sonar, and shallow-water anchors, the Mercury offers the best charging performance with a 226W alternator. Choosing the right power-to-weight profile between these two 4-stroke engines depends heavily on your specific boat's displacement and daily power requirements.