Mercury 9.9hp FourStroke EFI vs Johnson 9.9hp (4-Stroke)
9.9hp FourStroke EFI
9.9hp (4-Stroke)
| Spec | Mercury 9.9hp FourStroke EFI | Johnson 9.9hp (4-Stroke) |
|---|---|---|
| Power & Performance | ||
| Horsepower | 9.9 HP | 9.9 HP |
| Displacement | 209 cc | 302 cc ← |
| Configuration | 2 Cyl / Inline | 2 Cyl / Inline |
| Weights & Dimensions | ||
| Dry Weight | 38.5 kg (85 lbs) ← | 44 kg (97 lbs) |
| Mechanical & Electrical | ||
| Gear Ratio | 2.08:1 | 2.42 |
| Alternator | 145 W ← | 144 W |
| Fuel Delivery | EFI | Carbureted |
| Maintenance | ||
| Spark Plug | NGK DCPR6E | NGK CR6E |
| Engine Oil | Mercury FourStroke Oil 10W-30 | 10W-30 Marine |
Technical Comparison Analysis
Power & Displacement
Comparing the Mercury 9.9hp FourStroke EFI and Johnson 9.9hp (4-Stroke) shows a displacement difference of 93cc. The Johnson features a larger 302cc 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 38.5kg, offering a weight saving of 5.5kg 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 145W 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.