What is the lifespan of a bus? (9+ checks)

In this blog post, we will answer the following question: What is the lifespan of a bus? We will explain how through nine simple tests one can determine the lifespan of a bus and whether it is suitable for being on the road or not. 

​​What is the lifespan of a bus?

The lifespan of a school bus is 425,300 miles, an amount that, when divided by the average of 41, 7000 miles of travel per year, a bus yields a lifespan of 10 to 12 years. This is an estimate, however, as the real lifespan of a bus will depend on several factors:

  • How often do you service the bus;
  • What type of engine it has and what type of fuel you are using;
  • Where the vehicle is stored (whether exposed to harsh climate);
  • The condition of the tires;
  • The overall maintenance of the bus and your driving style. 

How is the lifespan of a school bus determined and checked?

In the US, specifically in Altoona Pennsylvania, the “Altoona Bus Testing and Research Center” operates, which under government sponsorship, performs verification of the bus models that will eventually circulate in the USA.

Testing is performed by Vehicle Safety and Systems Program staff at the Altoona Bus Testing and Research Center in Altoona, Pennsylvania. The testing fees are subsidized by federal funds. Currently, the Center handles up to eight buses at a time. 

During the course of the tests, most of the maintenance and repairs are performed by the Center’s staff. Over the course of testing thus far, Center staff identified more than 9,107 malfunctions, leading to many design changes.

Upon arrival at the Altoona Bus Testing and Research Center, each bus undergoes a detailed check-in procedure. The purpose of the check-in procedure is to document the condition and configuration of the new “arrived” bus model. 

Then nine tests are performed on the buses

  1. Safety, 
  2. structural integrity and durability, 
  3. reliability, 
  4. performance, 
  5. maintainability,
  6. noise, 
  7. fuel economy, 
  8. brakes,
  9. and emissions. 

These are not tests of approval or rejection; data from all tests are compiled into a test report that is made available to the manufacturer to provide information during the procurement process.

  1. Safety: The objective of this test is to determine the handling and stability characteristics of the bus by measuring the forward speed through a dual-lane change, obstacle avoidance course
  1. Structural integrity and durability: There are five procedures that comprise this test sequence.

Durability: The objective of this test is to determine certain structural characteristics (for example, deflection of the bus frame, permanent structural deformation, etc.) under static load conditions

Safety: The objective of this test is to observe the operation of various subsystems when the bus is placed in a longitudinal turn (simulating an operation on a 6-inch curb through a 6-inch pothole) and is subjected to a spraying mechanism of water simulating rain and traffic spray

Static towing: The objective of this test is to determine the strength characteristics of bus towing devices during static load conditions.

Dynamic Tow: The purpose of this test is to verify the integrity of the towing devices and determine the feasibility of towing the bus using a heavy wrecker and specified procedures

Jacking: The objective of this test is to determine the damage caused by a flat tire and to determine the feasibility of lifting the bus with a portable hydraulic jack to a sufficient height to replace a flat tire

  1. Reliability: The objective of this test is to evaluate the reliability of the bus by documenting unscheduled breakdowns, repairs, downtime, and repair time that occur during the test.
  1. Performance: There are two tests that comprise the performance test sequence.
  • Gradeability: The purpose of this test is to determine the acceleration, gradeability, and top speed capabilities of the bus. Time to speed for sequential speed increases at full power is measured using a stopwatch with a lap timer and then used to generate speed versus time graph and grade calculations
  • Brake performance: The objective of this test is to demonstrate the ability of the parking brake to hold the bus at 20 per cent and to measure the required stopping distance when the service brakes are engaged at various speeds.
  1. Maintenance, Preventive Maintenance and Repair Maintenance: The purpose of this test is to collect data on the maintenance, preventive maintenance and repair of the vehicle.
  1. Interior noise: The purpose of these tests is to measure and record interior noise levels and verify audible vibration under various operating conditions.

Exterior noise: The main goal is to measure exterior noise levels when operating a bus under various conditions

  1. Fuel economy and emissions: The objective of this test is to provide accurate and comparable data on fuel consumption in transit buses produced by different manufacturers. This test is not related to calculations made by the Environmental Protection Agency. The results of this test will not represent an actual “in service” fuel economy but will provide comparative data.
  1. Brakes, accessibility of components and subsystems: The goal of this test is to verify the general accessibility of the components and subsystems. Items that are checked are those that normally require maintenance or repair during transit service

All the data collected from the various tests on a bus is compiled into a report containing the test results and if requested by the manufacturer, recommendations for possible design changes or improvements. (There are no minimum performance standards for tests, nor are tests “pass” or “fail”). 

Prior to purchase, recipients requesting federal funds must obtain a copy of the report for the specific bus model to be purchased with federal funds. This allows the recipient to manage risk during the acquisition by providing an unbiased means of comparing bus performance on standardized tests.

And this is how the lifespan of a bus is determined. 

What is the lifespan of a school bus engine and how to maintain it?

School bus engines last 15 to 20 years or 250,000 miles if properly maintained and treated with care. 

In rare cases, the Skoolie engines will not even get to seven years, as the causes of wear and breakdowns are plenty. As the diesel engines were equipped with new components over the years, new failures related to these parts appeared. In rare cases, motorists have even witnessed the breakage of these parts. 

Frequent breakdowns in diesel school bus engines today include:

  • The injection pump,
  • The injectors,
  • The EGR valve,
  • The particulate filter, however essential to reduce the number of fine particles emitted in the exhaust.
  • The turbo, which tends to clog and is one of the common causes of engine failure.
  • The dual-mass flywheel, a transmission part commonly found on diesel models and known to break more often than rigid flywheels.

However, it must be admitted that manufacturers now master the design of these parts. While faults can still be observed on certain ranges, the fouling and breakage of engine parts are on the whole less numerous.

Whether you choose a gasoline or diesel vehicle, certain simple actions will help improve the life of your school bus engine:

  1. Refer to the maintenance book for your vehicle. This mentions the frequency of the tasks (such as oil change, for example, which must be carried out every 15,000 miles on average).
  1. Replace worn parts: Elements such as the oil filter or the timing belt influence a vehicle’s fuel consumption, but also its durability.
  1. For a used bus, choose manufacturer parts, in particular for your engine parts. These are more expensive but are generally more enduring.
  1. Let your vehicle warm up slowly. When warm, the engine oil will be more fluid and will do its job better.

If your budget allows it, the best diesel engine for a motorhome is an engine greater than 100 hp. You will have more comfort with a more powerful and more torquey engine, especially if you are travelling with a large payload. 


The lifespan of a bus, whether it is a commercial vehicle or a converted bus, will mainly depend on you as a driver. As we have already established in this article, how well you maintain and store your bus will greatly affect its durability. 

When checking if a bus is still good to drive, you can go over the nine tests mentioned above to make sure that you are safe on the road. 

If you have any questions or comments on the content, please feel free to share them with our other readers!

FAQ on What is the lifespan of a bus?

How many miles is too much for a used bus?

250,000 miles are considered too much for a used bus. Of course, there are buses that have less than 12 years on the market, many more miles on the meter and still go well. It all depends on the condition of the vehicle, so make sure regular maintenance is on your calendar. 

What is the oldest bus?

The oldest bus would be horse-drawn buses that were popular in the 1820s. The first buses as we know them today (almost), meaning internal combustion engine buses, or motor buses, made their appearance in 1895.

Are Skoolies a good investment?

Skoolies are a good investment as long as you are willing to commit to the conversion process and are ready financially speaking. A Skoolie can become a great RV or even a more permanent home. 

How much is a Skoolie worth?

A Skoolie is worth $20,000 to $30,000 for the initial build-out. Depending on the number of amenities and modifications that you are going to make, the worth of your Skoolie will increase significantly. 

Other FAQs about Skoolie that you may be interested in.

Can you live in a bus in the UK?

Can I live in a bus on my own land?

Are Skoolies expensive to maintain?


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