The question of the efficiency of water equipment worries every owner of the boat, because the cost of a liter of gasoline at gas stations is constantly growing, and the pleasure of cruising should not be clouded by anxiety for an empty tank. Mercury's outboard motor It's rightly considered a market leader, but even this giant has its own energy consumption specifications. outboard At different turns, it is critical for planning long-distance routes and fishing.
Many beginners mistakenly believe that the specifications declared by the manufacturer are the absolute truth under all conditions, but the actual operation makes its own adjustments. fuel It is influenced by many factors, from the condition of the propeller and loading of the boat to the quality of the fuel and weather conditions. In this article, we will examine in detail how the Mercury technique behaves in practice, and help you learn how to calculate the necessary gasoline supply with high accuracy.
It's worth noting right away that the difference between two-stroke and four-stroke units can be huge, and you can't ignore this aspect when choosing. If you want autonomy and the ability to go long transitions without refueling, then knowing the nuances of the work is important. injection-system Let's dive into the technical details so that your next water trip is as efficient as possible.
Factors Affecting the Appetite of the Engine
The first thing to consider when calculating the fuel budget is the design features of the engine itself. Mercury Historically, more mixtures have been consumed because of lubrication, where some oil is simply burned in the cylinder. Modern four-stroke engines are based on car engines, where the oil is in the crankcase, which makes them much more economical, especially at medium speeds.
But it's not just the type of cycle that matters, but the aerodynamics of the boat and the state of the bottom of the boat are hugely influential, and the shells, the algae, or even just the accumulation of dirt on the transom and the lower unit, create additional water resistance. Hydrodynamic resistance causes the motor to operate at higher revs to maintain the same speed, which naturally increases fuel consumption.
⚠️ Attention: Ignoring antifouling treatment or regular bottom washing can increase fuel consumption by up to 15-20% per season.
You can't discount the captain's driving style, either. The sharp openings of the throttle, the constant acceleration and braking, the movement against the current or the strong wave - all this makes you feel like you're driving. fuel-system It's always better to have a smooth planing at optimal speed than a ragged rhythm.
- 🚤 The engine type (2T vs 4T) determines the basic level of efficiency.
- 🌊 The hydrodynamics of the body and the purity of the bottom directly affect the resistance.
- 🌬️ Weather conditions (wind, wave) can increase the load on the engine.
- 🔧 Technical condition (candles, filters, compression) affects efficiency.
Comparison of two-stroke and four-stroke models
In choosing between two-stroke and four-stroke Many people look only at price and weight, forgetting about the long-term savings. Mercury two-stroke engines, especially the older series, require a fuel mixture where some of the gasoline simply flies into the atmosphere through exhaust, which is not only environmentally harmful, but also financially costly, because you actually burn money.
Four-stroke units, such as the popular series FourStrokeThey're much more stable and predictable. They're not as noticeable at idle and trolling, but when you go plane and cruising, the 4Ts are more advantageous, and they're quieter, and they don't require oil to mix with gasoline.
Modern two-stroke motors with a system direct-injection Direct Injection, for example, series OptiMaxThey're more efficient than carburetor models, but they're less efficient than the classic 4T at low speed, and it depends on whether you're going to have weight and dynamics or maximum autonomy.
- ⛽ 2T engines consume 30-40% more fuel at high speeds.
- 🛠️ 4T engines are more difficult to maintain, but cheaper to operate.
- 💨 The optimal mode for 2T is full gas, for 4T - 70-80% of power.
Table of Mercury fuel consumption at different speeds
So to give you a sense of the numbers, we've compiled a summary of the averages for popular mid-power models, and remember that these values are relevant for standard conditions: calm water, average boat load, and proper engine. Real values can range from 10 to 15 percent.
The table shows the data for a motor with a power of about 15-20 hp, as it is the most common class for small and medium-sized boats. Turnover is indicated as a percentage of the maximum power (WOT - Wide Open Throttle), which allows you to extrapolate the data to other models of the same class.
| Mode of work | Turnover (% of max) | Speed (km/h) | Consumption (l/hour) 2T | Consumption (l/hour) 4T |
|---|---|---|---|---|
| Idle move | 10-15% | 3-5 | 0.8 - 1.2 | 0.5 - 0.8 |
| trolling | 30-40% | 8-12 | 2.5 - 3.5 | 1.5 - 2.0 |
| Cruiser | 60-70% | 25-35 | 6.0 - 8.0 | 3.5 - 5.0 |
| Full gas. | 95-100% | 45-55 | 10.0 - 12.0 | 7.0 - 9.0 |
And if you look at the chart, you can see that at the cruising speeds that are most commonly used in transitions, a four-stroke engine saves almost twice as much fuel, and this becomes critical when planning long-distance exits, when every litre canister counts. The efficiency of the mixture in 4T engines really works miracles of economy.
Remember the simple rule: the most economical mode for a 4T engine is 70-75% of the total power (about 4000-4500 rpm).
How to calculate the power reserve for your boat
It's not just about mapping a course, it's also about math, and to figure out how many kilometers you can walk on a single tank, you need to know not only the volume of the fuel tank, but the actual volume of the fuel tank. hourlyThe formula is simple: divide the tank by the flow rate per hour and multiply by the speed.
For example, if you have a 25-liter tank and you are traveling at 30 km/h, consuming 6 liters per hour, then your reserve will last about 4 hours or 120 kilometers. stock-stock 20-25% of the total in case of unforeseen circumstances, headwinds or errors in calculations.
It is important to consider that with a decrease in the level of fuel in the tank, its weight also changes, which can slightly affect the differentiation of the boat and, as a result, the flow rate. In addition, with a long parking lot with the engine running (for example, when waiting for a fish or a storm), the flow is only in time, and not in distance traveled.
☑️ Calculation of range
⚠️ Warning: Never plan a sideways route. In the water element, weather conditions can change in minutes, and you have to go against the wave, which will increase fuel consumption.
The secrets of fuel economy in practice
There are many ways to reduce gasoline consumption without compromising comfort, the first and most important step is to get the propeller right, and taking too much will make the engine run in low-speed overload mode, and too little will prevent it from plane and cause the engine to be twisted. Screw pitch The boat must be weighed and the owner’s tasks.
Regular maintenance also plays a huge role: polluted spark plugs, an old fuel filter or an incorrectly exposed ignition advance angle can increase consumption by 10-15%. carburetor or a nozzle, especially if you use gasoline with ethanol, which can leave deposits.
Effects of ethanol in gasoline
Modern gasoline often contains up to 10 percent ethanol. It's an oxygenate that makes the mixture poorer. If your Mercury engine isn't adapted to the E10, the engine can consume more fuel to compensate, and it can also damage the rubber seals in the fuel system of older models.
Also worth paying attention to the distribution of cargo in the boat: shifted to the nose or on one side of the load disrupts the hydrodynamics, causing the engine to work harder, even loading and the correct installation of the engine in height of the transom will help to achieve optimal position of the boat on the water and reduce drag.
- 🔩 Choose the screw so that the engine goes to working speeds (5000-5500) at full gas.
- 🧼 Wash lower unit regularly from seaweed and shells.
- ⚖️ Spread your passengers and equipment evenly in the cockpit.
Common mistakes that increase the cost
One of the most common mistakes is using an overpowered motor for a light boat. The owner buys a powerful one. Mercury "for growth" or for speed, but eventually forced to constantly throttle the gas, operating in an inefficient range of revolutions, the engine must operate at its optimal range, not at 20% power.
Another mistake is ignoring the quality of the fuel, and refueling at untested gas stations can lead to water entering the tank or using low-octane gasoline, the engine starts detonating, the electronics (or mechanics) adjust the mixture, and the engine starts to detonate. combustion-efficiency In the long run, it also threatens to repair fuel equipment.
And remember, warm-up. Although modern Mercury engines are ready to go almost immediately, aggressively starting to go on a cold engine causes the system to enrich the mixture, which leads to overruns. Give the engine 1-2 minutes to work in calm mode before going to the planing.
The secret to saving is not only technique, but also the discipline of the captain. Smooth passage, clean bottom and the right screw work wonders.
Does the water temperature affect fuel consumption?
Yes, it does, but it's not critical. Cold water is denser, which creates a little more resistance, but it improves the cooling of the engine, allowing it to work more efficiently, and the main influence is air temperature and atmospheric pressure.
Can I use AI-92 gasoline for Mercury?
Most current Mercury engines are adapted to 92 octane gasoline (research method), which is the same as the Regular 87 in the US. However, always check the specific model instructions, as some high-power versions require the 95.
Why did the cost increase after the winter conservation?
Probably, the fuel system was left with decay products of old gasoline, clogged carburetor or injector gillers, and could dry out the seals, allowing excess air, which impoverishes the mixture and disrupts the engine.