Tohatsu MFS20 (4-Stroke) vs Mercury 18hp (2-Stroke)
MFS20 (4-Stroke)
18hp (2-Stroke)
| Spec | Tohatsu MFS20 (4-Stroke) | Mercury 18hp (2-Stroke) |
|---|---|---|
| Power & Performance | ||
| Horsepower | 20 HP | 18 HP |
| Displacement | 351 cc ← | 300 cc |
| Configuration | 2 Cyl / Inline | 2 Cyl / Inline |
| Weights & Dimensions | ||
| Dry Weight | 52 kg (115 lbs) | 39 kg (86 lbs) ← |
| Mechanical & Electrical | ||
| Gear Ratio | 2.15:1 | 2.0 |
| Alternator | 145 W ← | 60 W |
| Fuel Delivery | Carbureted | Carbureted |
| Maintenance | ||
| Spark Plug | NGK DCPR6E | NGK B7HS |
| Engine Oil | Tohatsu 4-Stroke Oil | TC-W3 2-Stroke |
Technical Comparison Analysis
Power & Displacement
Comparing the Tohatsu MFS20 (4-Stroke) and Mercury 18hp (2-Stroke) shows a displacement difference of 51cc. The Tohatsu features a larger 351cc 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 39kg, offering a weight saving of 13kg 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 Tohatsu 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.