The question of how many liters a bus’s fuel tank can hold often arises not only among engineers and logisticians, but also among drivers, and even among inquisitive passengers watching the giant vehicle being refueled. The answer to this question cannot be unambiguous, since passenger transport is a huge class of equipment, including both compact minibuses and double-decker airliners for long-distance travel.
The tank capacity directly dictates power reserve vehicle, which is a critical parameter for route planning. If a city bus can afford frequent stops at gas stations within one depot, then an intercity bus liner must confidently cover hundreds of kilometers without refueling. That is why engineers pay special attention to the layout of the fuel system when designing the chassis.
In this article, we will look in detail at what the volume of the tank depends on, how to calculate the actual flow rate, and why the numbers in the technical documentation may differ from reality. Understanding these nuances will help you better navigate the characteristics of public transport.
Factors Affecting Fuel System Capacity
The first thing to consider when analyzing tank volume is bus class. City cars that constantly travel short distances and stop often are usually equipped with smaller tanks compared to tourist models. For them, maneuverability and weight distribution are more important than a huge fuel supply.
The second important factor is the type of engine used and its environmental class. Modern diesel units that meet standards Euro-5 or Euro-6, can be more economical, allowing engineers to avoid over-sizing the tank. However, powerful engines that develop high torque on the highway require a significant amount of diesel fuel to ensure continuous operation.
It is also worth mentioning the design features of the chassis. The tanks can be located on the sides of the frame, at the rear, or even divided into several sections for balancing. The standard tank volume of a modern city bus is from 200 to 300 liters, while for long-haul airliners it often exceeds 500 liters.
The location of the tank affects safety and ease of maintenance. Engineers strive to place the container in a way that minimizes the risk of damage in an accident and provides easy access for the refueling nozzle.
City buses: optimized for short distances
The urban rhythm of traffic dictates its own rules of the game. Constant acceleration, braking and idling of the engine when the doors are opened lead to specific fuel consumption. Therefore, the tank volume here is calculated taking into account the possibility of refueling in the bus depot at the end of a shift or during a lunch break.
Most modern urban models such as LiAZ, MAZ or Volgabus, are equipped with tanks with a volume of about 250 liters. This volume is enough to work a full shift (10-12 hours) with a small margin. An increase in volume would lead to an increase in the weight of the vehicle, which would negatively affect dynamics and braking in heavy traffic.
It is important to note that in urban environments they are often used gas engine fuel systems. In such cases, compressed natural gas (CNG) cylinders are installed instead of a diesel tank or in addition to it. The volume of gas equipment is no longer measured in liters of liquid fuel, but in cubic meters or kilograms, but in terms of energy equivalent it allows you to travel the same distances.
It is also worth considering that in winter, fuel consumption in the city can increase by 15-20% due to the heating of the cabin and the operation of heaters. Therefore, dispatch services always plan refueling taking into account seasonal coefficients so that the bus does not stop in the middle of the route.
Intercity and tourist liners
The situation is completely different with intercity buses. These vehicles are designed to cover long distances at high average speeds. Here comes to the fore power reserve, which should be at least 600-800 kilometers without refueling. This requirement is due to the fact that there are not always suitable gas stations on the highway, and stopping a large bus in the wrong place is prohibited by the rules.
The volume of tanks in machines such as Setra, MAN Lion's Coach or Yutong, often reaches 400-600 liters. Some premium models are equipped with two tanks, the total volume of which can reach up to 900 liters or more. This allows interregional transportation operators to build routes without being tied to frequent refueling.
⚠️ Attention: When planning long trips on a tourist bus, always take into account the real, not the passport, power reserve. Luggage load and the number of passengers have a significant impact on fuel consumption.
Body aerodynamics also play a role. Modern airliners have a streamlined shape, which reduces air resistance and, as a result, fuel consumption. This allows you to travel a greater distance with the same tank volume compared to previous years' models.
Drivers of such vehicles undergo special training in economical driving. Smooth acceleration and movement in the optimal engine speed range can significantly save fuel, which is critical with large tank volumes and high diesel prices.
Comparative table of tank volumes of different models
To better understand the numbers, we will give specific examples of popular bus models used on the roads of the CIS and Europe. Data may vary slightly depending on the year of manufacture and chassis modification.
| Bus model | Type | Tank volume (liters) | Approximate range (km) |
|---|---|---|---|
| LiAZ-5292 | Urban | 250 | 350-400 |
| MAZ-203 | Urban | 280 | 380-420 |
| Volgabus-5270 | Urban | 240 | 340-380 |
| MAN Lion's City | Urban | 300 | 400-450 |
| Setra S 516 HD | Tourist | 560 (2x280) | 800-900 |
As can be seen from the table, the difference in volumes between urban and tourist class can be twofold. This is a fundamental difference that determines the logistics of running a fleet.
When choosing equipment for transport companies, these parameters are among the key ones when calculating cost per kilometer. A larger tank means fewer trips to the gas station, but also the volume of “frozen” funds in the form of fuel.
Tank volume is a compromise between range, vehicle weight and the layout of usable space for passengers and luggage.
Fuel consumption and range calculation
Knowing the volume of a tank is not enough unless you understand how quickly fuel leaves it. Fuel consumption for a bus, the value is extremely variable. It depends on the curb weight of the vehicle, the passenger load, the terrain, the condition of the road surface, and even the operation of the air conditioner.
In urban conditions, consumption can reach 40-50 liters per 100 kilometers due to the start-stop mode. On the highway at a speed of 80-90 km/h this figure drops to 25-30 liters. However, when driving at high speeds (110 km/h and above), consumption again increases sharply due to aerodynamic drag.
- 🚌 City cycle: Frequent stops, engine idling, low speeds - high consumption.
- 🛣️ Trace cycle: Uniform movement, use of inertia - optimal consumption.
- 🏔️ Difficult terrain: Climbing uphill requires maximum engine output, which increases diesel consumption by 1.5-2 times.
To accurately calculate the power reserve, logisticians use the formula: Cruising range = (Tank volume / Consumption per 100 km) * 100. However, it is always laid emergency reserve (usually 10-15% of the volume) to eliminate the risk of stopping due to errors in fuel level sensors or unexpected traffic jams.
Modern telemetry systems allow dispatchers to monitor fuel levels in real time and predict the need for refueling by analyzing the current driving style and route.
Fuel Safety and Maintenance
A large volume of diesel fuel means not only energy, but also increased responsibility. The bus fuel system is equipped with many filters, sensors and valves. Fuel filters require regular replacement, since the quality of diesel at different gas stations can vary greatly.
In winter, the use of winter or arctic grades of diesel fuel is critical. At low temperatures, paraffins form in summer diesel engines, which clog filters and can completely immobilize the car. In this case, the volumetric tank takes longer to cool down, but it is also more difficult to warm it up.
⚠️ Attention: Never allow the tank to become completely empty (“dry”). This can lead to air in the system and failure of the expensive high-pressure fuel pump (HPF).
It is also important to keep the tank neck clean and the lid tight. The entry of water or mechanical debris into a tank with a volume of 500 liters can lead to a major overhaul of all fuel equipment, which is an extremely costly procedure.
Why are tanks made of aluminum or plastic?
Modern tanks are often made of aluminum alloys or special polymers. Aluminum does not rust, which prevents corrosion products from entering the fuel system. Plastic (high-density polyethylene) allows you to create tanks of complex shapes, effectively using frame space, and is not subject to corrosion at all. Steel tanks are becoming a thing of the past due to their weight and tendency to rust.
Prospects: electrification and alternative fuels
The public transport industry is changing rapidly. Diesel giants are being replaced by electric buses. In them, the concept of “tank volume” is transformed into “battery capacity”. If the volume in liters is important for a diesel engine, then for an electric train it is kilowatt-hours (kWh).
The battery capacity of modern electric buses can reach 300-400 kWh, which allows them to travel up to 200-300 km on a single charge. However, the “refueling” (charging) time is significantly higher than refueling with liquid fuel, which requires a restructuring of the entire fleet logistics.
At the same time, hydrogen fuel cell technologies are being developed. Hydrogen is stored in cylinders under high pressure. Here, volumes are measured in kilograms of hydrogen, and the range is already comparable to diesel counterparts, with the only exhaust being water.
Despite this, diesel buses with large tanks will remain the mainstay of transport for a long time in remote regions where the infrastructure for alternative fuels has not yet been developed.
When ordering a bus for corporate needs, pay attention to the presence of a pre-heating system for the engine and interior. This will save fuel on warming up and extend the life of the engine in the cold season.
Frequently asked questions (FAQ)
Why does the bus have two fuel tanks?
The presence of two tanks (or one divided into sections) allows you to increase the overall range without violating the overall width restrictions. In addition, it improves the weight distribution of the car. Often the tanks are connected to each other, and fuel is pumped from one to another automatically or manually by the driver.
How often do you need to refuel a city bus?
Typically, a city bus is refueled once a day, at the end of the work shift at the depot. During intensive use on long routes, additional refueling in the middle of the day is possible if the tank volume is less than 250 liters and the route exceeds 300 km.
Does a full tank affect fuel consumption?
Yes, it does. A full tank of diesel fuel (about 300-500 liters) adds 250-400 kg of weight to the car. Compared to a half-empty tank, fuel consumption can increase by 1-3%, which makes a noticeable difference over long distances.
Is it possible to put gasoline on a bus?
Absolutely not. Almost all modern buses are equipped with diesel engines. If gasoline gets into the diesel fuel pump, it will immediately fail due to the lack of lubricating properties of gasoline, which will require expensive repairs of the entire system.
What is the actual mileage of the bus before major repairs?
The service life of a modern diesel bus engine before major overhaul ranges from 800,000 to 1,500,000 kilometers, depending on operating conditions and quality of service. The body and frame last much longer.