market dynamics
Motorcycle engine only 1/12 of the car, why the fuel consumption is half of the car?
Release date:2021.01.14

Studied two engine principle all know, it will be four salt intake, compression, actuation, exhaust, a total of four process is simplified to two process, the purpose is the reduced volume, lose weight, but it cannot be completely separated in time, and air intake and exhaust that is useful mixture haven't work is out of a small part, of course, some oil.

According to the commonly used 125 motorcycles to calculate, infinitely variable speed scooter basic fuel consumption in four litres. Men's straddle gears are basically two to three litres. At six yuan per liter, it's about 40 cents a kilometer for pedaling and 2-3 cents a kilometer for straddling. Comprehensive fuel consumption. The comprehensive fuel consumption of a 1.5 car is about six to eight liters on average, which is about 80 cents per kilometer. That is, straddling a motorcycle car four minutes of fuel consumption, pedal half of the fuel consumption. Fuel consumption is high because small displacement in order to get better power, must do high speed. High speed is the cause of high fuel consumption. Motorcycle engines run at 15, 000 RPM, which is rarely used in cars.

It's true that motorcycles use more fuel per unit weight than cars, but you have to calculate it according to the mileage ratio. And you said 125 motorcycle 30 cents a kilometer? Is that a dead car or a knockoff pedal? Or the one that smokes. My racing boat is a little over 20 cents a kilometer with 250 and 95 fuel. A little more than ten cents. I used to ride a Honda 190th gear car more economical, too lazy to calculate how much money. Use 500 ml single cylinder machine, low speed, may save fuel! The main problem with motorcycle engines is that they need high revs to start and accelerate! And the car four cylinder torque is large, do not need too high speed to start! There's too little torque in the motorcycle engine.


Automotive electric injection for many years, now the development of direct injection. Motorcycles have always been driven in carburetors, but only in recent years have they been electrically injected. In addition to the mechanical reasons of the engine, the electrical control part is also very important. After the electric spray on the motorcycle, fuel consumption also fell a lot, 1.8 to 2 liters of 100 kilometers generally. Resistance that can also be assigned to the very fine, because of fuel consumption is not only related to displacement, and also the weight, friction, wind resistance, rotational speed and torque are related, the car very little wind resistance, because be streamlined, motorcycle wind resistance is large, automotive vehicle weight, the friction drive wheels are helpful, motorcycle light, good friction force is small, the car speed is low, high motor speed, motor torque, torque small motorcycle!!!!! Cars are 3-4-6-8-12-16-32 cylinders, while motorcycles are 1-2 cylinders. Great racing bikes can be up to 4 cylinders! The lighter that says with you to boil water a principle!

The most important is the lack of thermal efficiency. Now the thermal efficiency of cars is almost 40 percent. Motorcycles, on the other hand, have a low thermal efficiency because of their two strokes. Another is a motorcycle running resistance and car resistance is not the same. Because cars are designed to be streamlined without branching. Not so with motorcycles. So if you go faster, the wind resistance is still very high.

How do you tune an engine after it leaves the factory? What items are taught? Engine manufacturers, according to the design concept, design the size of the internal parts (mainly the crank connecting rod mechanism), to produce a qualified engine. The connecting rod of the engine is long, and the crank length on the crankshaft is long, so the working characteristics of the engine are: low speed and large torque, large volume and heavy weight, bulky (relatively speaking). On the contrary, high speed torque small volume weight (relatively speaking) is light. Motorcycle engines need this feature. The same is true for a diesel engine (low RPM, high torque) and a gasoline engine (high RPM, low torque). The fuel consumption of a petrol engine is wrong in litres / 100km. The correct statement should be: gram per kilowatt hour is the most reasonable. A (displacement of 150) motorcycle weighs about 130 kg +70 kg (one person), and a (displacement of 1500) car should weigh 2,000 kg. In this way, the fuel consumption can be compared.

Put aside the actual use of conditions to talk about fuel consumption, is tantamount to playing rogue. 1: Motorcycle engines do consume more fuel than cars, which is undeniable. But that is not the main factor. 2:125 The dead weight of a motorcycle is about 140 kg. A 1.5 liter car is about 1300 kg. A person is about 70 kg. The weight of a motorcycle when driving is about 50% of its dead weight. Look at the actual fuel consumption again, there is no difference with the motorcycle so big.

The public upgrade motorcycle weighs about 200kg, the displacement is 1000ml, and the highest speed is about 13000. The fuel consumption for 100 kilometers is about 10. The small displacement car weighs about 1.2 tons, the displacement is 1.2 liters, the highest speed is about 6000 revolutions, and the fuel consumption is about 6 liters. The displacement is larger, the car is 6 times heavier, but the fuel consumption is lower, mainly or the adjustment, the car pays attention to the low twist, the motorcycle pays attention to the high turn. Simply speaking, the engine of a car is more efficient, while the engine of a motorcycle is smaller and less efficient. The simplest way is to compare a 125cc motorcycle engine to a 1.2T car engine. The displacement difference is about 10 times. But the fuel consumption is definitely not 10 times the difference. Three times at most. It can be seen that cars are much more fuel-efficient.

Compare the two engines, directly see litre power, compare the two cars, see ton power! Only these two parameters are the same, and then compare the fuel consumption! 125, although only 0.125 litres, compared to the car, the speed is almost twice the car, so it should be reduced to 0.25 litres for comparison. So, the general 125 motor power 8-9KW, and 1.5 liter car general 60-80KW. Liters are 35 for motorcycles and 66 for cars. Pedal is suitable for running urban area only, fuel consumption is in 3 liters generally, say 2 liters estimate did not ride pedal well. As a result of litre power car than motorcycle big nearly one times, motorcycle fuel consumption should be 6, and car about the same! Obviously, the fuel consumption of motorcycle is nearly one time higher than that of car, indicating that the engine efficiency of motorcycle is far lower than that of car. From the tons of power contrast ~ motor general 0.1 tons, 1 tons of car!

If the motorcycle weight amplification to the car, obviously motorcycle fuel consumption is much higher! The reason why the motorcycle fuel consumption is high, first of all, the engine in the fuel consumption economy to give way to the weight of the engine, as far as possible lightweight engine, can be suitable for motorcycle; Secondly, the wind resistance of motorcycles is more than the car, but also the fuel consumption is high! In fact, the motorcycle engine is high speed, that is, in order to improve the power, the main purpose is to reduce weight! The purpose of car weight reduction is only one, is to reduce fuel consumption and the main purpose of motorcycle weight reduction is to control, followed by fuel consumption. In the end, motorcycles save fuel, only when carrying 1-2 people, not in terms of car weight or the same displacement engine!