Keeping Diesel Bus and Coach Fleets Clean: A Guide to Minimising Emissions

The reputation of diesel engines has tanked in recent years due to the increasing focus on the environmental impact of carbon emissions. But there is more than one side to this story, and many reasons to remain optimistic about the future of clean diesel. In this blog, we cover the continued benefits of using diesel vehicles and how drivers and fleet managers can help to minimise the CO2 emissions of coach and bus travel.

By Foxwood Diesel On 11th May 2026

Diesel Bus and Coach Carbon Emissions

Diesel bus and coach fuel consumption and carbon emissions are notoriously high due to inefficient acceleration patterns, heavy loads and the nature of diesel combustion. Left unfiltered, soot pollutes the air and damages the environment. However, given that diesel engines are designed for endurance and superior fuel efficiency, they remain an excellent choice for high-mileage drivers.

In fact, driving longer distances in a bus or coach allows the Diesel Particulate Filter (DPF) to reach operating temperatures and burn off soot. In investigating how the emissions of particulates are minimised, a 2014 study showed that DPFs and other after-treatment systems can reduce emissions by around 95%. Environmentally speaking, buses and coaches are actually the best diesel vehicles to drive.

"The negative press surrounding diesel engines could lead to panic and worry amongst fleet managers. Bus and coach fleets tend to be older so don’t benefit from the pollution reducing technology now fitted to new diesel vehicles. However, you can still manage the emissions of older diesel vehicles by ensuring they follow the manufacturer's maintenance schedule. You could also consider retrofitting diesel particulate filters.”
Ken Worsdale, Managing Director of Foxwood Diesel

Maintaining a Clean Diesel Engine

Foxwood Diesel has specialised in diesel engines since 1988 and witnessed the evolution of thinking around the carbon emissions of buses and coaches. As experts in diesel bus and coach engine repair, we also routinely recondition DPFs and sell products that can ensure your fleet runs as cleanly as possible.

For example, Forté Diesel Particulate Filter Cleaner and Regenerator enables passive regeneration in the DPF, reducing carbon emissions and improving the stability of the filter. The cleaner adds catalysts to the fuel, which chemically bind with soot to lower the combustion temperature and prevent soot from accumulating inside the DPF.

Forté Diesel Particulate Filter Cleaner and Regenerator is formulated to combat the adverse effects that low exhaust temperatures, caused by stop-start driving on bus routes amid city traffic, have on diesel engine DPFs. For best results, we recommend using Forté DPF Cleaner and Regenerator at regular service intervals.

Cleaning Diesel Particulate Filters

As well as using cleaning diesel fuel additives, there are several ways to keep a DPF in top working condition. These include:

Drive long distances
So that the DPF can reach sufficiently high temperatures to burn off soot, avoid short-distance or stop-start journeys.

Regenerate the engine
At least once per week or per tank of fuel, take your diesel bus or coach for a longer, higher-speed drive to allow the engine to regenerate.

Use low-sulphur diesel
High-SAPS (Sulphated Ash, Phosphorus and Sulphur) fuel can quickly clog the DPF, so stick to diesel labelled low- or medium-SAPS.

Keep the tank topped up
Ensure the tank is never less than a quarter full, as many systems won’t initiate automatic regeneration with low fuel.

Reconditioning
Despite regular cleaning, DPFs degrade over time like any other diesel engine part. If yours isn’t performing at its best, Foxwood Diesel offers full reconditioning services.

We Help Keep Diesel Carbon Clean

That they are 'dirty' is one of many myths about diesel engines. With proper care, diesel buses and coaches can be optimised to produce fewer CO2 emissions and serve in reliable fleets for years and years.

Our skilled engineers and customer team at Foxwood Diesel will gladly answer any queries you may have about how to minimise the emission of carbon particulates from your vehicles. For more information about DPFs and everything diesel, please contact us or visit our blog.

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