How to Drive for Better School Bus Fuel Economy

View from the drivers seat of a school bus


Vancouver School Bus is part of the transport industry which creates a great deal of greenhouse gas emissions in British Columbia. According to the LiveSmart BC website, 36% of all greenhouse gases emissions in BC were from transportation industry and this number will only grow going forward. We can do our part by changing our everyday driving habits with a focus on school bus fuel economy.


The City of Vancouver has a goal of becoming the greenest city in the world by the year 2020. If we’re not part of the solution, then we’re part of the problem. Building a small business that employs principles of sustainability is good for both the environment and as well as the bottom line. So over the next few months, we’ll be making efforts to reduce the emissions created by our buses through better bus driving habits. Here are some of the driving habits we’ll be using:


1) Don’t accelerate and brake aggressively. Look ahead and coast when possible.
A fully loaded school bus can weight as much as 46,000 lbs. so accelerating requires a tremendous amount of fuel, not to mention the wear and tear on the brakes and tires. Drivers should learn to look ahead and anticipate when they will need to slow down or stop so they can avoid accelerating needlessly. This will use less fuel, reduce wear on the entire braking systems and provide a smoother and more comfortable ride for our passengers!


2) When accelerating, use the torque of the diesel engines.
Diesel engines are most efficient (they produce the most driving force per unit of fuel) at certain engine speeds. On our diesel engines, this range is from 1400rpm to 2500rpms. Drivers should smoothly accelerate from stops operating within these ranges, thereby ensuring that the engines are being run at their peak torque efficiency zone.


If drivers make a habit of shifting too early and operating the engine below the optimum range, this will lead to high carbon buildup in the engine over time which reduces overall efficiency. The result is higher fuel consumption, more emissions and unhealthy school buses.


3) Drive at or below the posted highway speed limits.
All vehicles consume more fuel if driven at highway speed because more energy is required to overcome wind resistance. School buses aren’t known for their aerodynamics so this is especially important for us. Besides being illegal, driving above the speed limit on the highway (approximately 80km/h – 100km/h) will affect the fuel economy of diesel engines more so than equivalent gas engines. As mentioned earlier, diesel engines have an optimum operating range for fuel economy and are even more sensitive than equivalent gasoline engine when operated outside of this range. Our drivers are aware of the critical effect that wind resistance has on our buses and will adjust their driving habits accordingly.


4) Minimize idling.
Although idling a vehicle to warm up the engine is common practice, it is actually wasteful and produces needless greenhouse gas emissions. Modern engines need just enough time to circulate the engine oil before you can drive away. On our buses, this should take about half a minute. Emissions can double in a cold engine, so idling on a cold winter day is like dumping unburnt fuel out the tail pipe and into the environment. The best way to warm the engine and all other components is to start driving, especially diesel engines which are designed to run at operating temperatures for long, sustained periods of time rather than idling at a standstill.


If you are stopped for more than 10 seconds (except in traffic), you’ll save fuel by turning off the vehicle and then restarting it when its time to drive again. This includes situations like loading and unloading passengers or stopping in viewing areas. If you know that you’re going to be stopped for more than 10 seconds, turn off the engine rather than waiting it out. It’s bad for the environment, hard on fuel costs and it also emits loads of smelly diesel exhaust fumes. You can restart your vehicle knowing that your engine will still be sufficiently warm, the engine oil will be at the proper operating temperature and your catalytic converter will still be hot.


Besides the wasted fuel, idling can be really hard on the engine parts! If the engine idles while below peak operating temperatures, the fuel won’t undergo complete combustion. This leaves unburnt fuel residues that can contaminate engine oil and damage engine parts which are essential for optimum fuel mileage. Excessive idling can also let water condense in the exhaust system which will lead to corrosion and reduced life span.


Diesel Geeks Unite!
If you are a diesel geek like we are at Vancouver School Bus, please feel free to comment on these driving tips and share your own hypermiling experiences. In the future, we hope to share measurable improvements in both our fuel consumption and (fingers crossed) school bus maintenance costs.

This entry was posted on Tuesday, July 12th, 2011 at 12:01 amand is filed under Do The Right Thing. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

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