Diesel fridges, fuel duty and what you're actually signing up for

If you run refrigerated trailers, the last few years have been quietly more and more expensive.

First, most operators lost the ability to use red diesel for fridges and depot equipment. From April 2022, the entitlement to rebated fuel was removed for most sectors, including commercial refrigeration, so fridge tanks had to move onto full duty white diesel.

Now the November 2025 UK Budget keeps fuel duty where it is for a short period, then plans to put it up and keep it rising.

None of this is good news if you are trying to keep a cold chain running on tight margins. We are not cheering it on. But if you are thinking about buying more diesel fridges, it is worth being clear on the numbers you are locking in.

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What has actually changed on fuel duty

Right now, fuel duty on diesel is 52.95p per litre, a rate that has been frozen since the 5p cut in 2022. The latest announcements and OBR forecasts say:

·      5p freeze is being kept in place until 2026

·      From 2026–27, that 5p cut is unwound and we go back towards 57.95p per litre

·      Then from April 2027, fuel duty is planned to increase every year in line with RPI inflation

If you run the numbers on a simple 3.5 % annual inflation assumption, duty on diesel is around 81.8p per litre in 2037. That is roughly: +28.9p per litre compared with today or about 55% more fuel duty per litre

That is just the tax part, before you even look at the wholesale price of diesel.

What this does to one diesel fridge

The picture becomes real when you look at the fridge, not the tractor. Take a typical trailer fridge in long haul use: about 4,000 litres of diesel per year for refrigeration

At today’s duty rate of 52.95p per litre that is £2,118

By the mid 2030s duty could be around 81.8p per litre.

That is about £1,150 more tax per trailer per year for the same fridge doing the same work.

Because fridges are long life assets, the difference adds up over time. Call it around £6–7k in extra fuel duty per diesel fridge over a 10 year life, just because of how duty is planned to move.

When you buy a diesel fridge now, you are not just buying hardware. You are buying ten years of exposure to a tax that is set to rise.

Scale that to a real fleet

Most fleets reading this are not buying a single fridge.

If you have 100 diesel refrigerated trailers, the same logic gives you around £670,000 in additional fuel duty over a decade to run the same diesel refrigeration.

This is on top of everything else you already carry on diesel fridges: a separate engine on the front of the trailer, more moving parts, regular servicing, and the occasional breakdown exactly when you do not need it.

From our side, the point is simpler: these tax changes are long term. They outlive any individual Budget speech and they stretch across the life of any diesel fridge you buy in the 2020s.

Diesel is not disappearing from fleets next week but our mission is to give operators a real choice.

That is where Endurance, our electric transport refrigeration system, comes in.

Because it is battery and solar-powered, there is no diesel, no diesel tank, and no fuel duty on the refrigeration side. That is why fleets running Endurance are seeing up to 81% lower operating costs compared with diesel fridges in real use – before factoring in the fuel duty rises.

So where does that leave you if you are planning refrigeration for the next few years?

If you would like to see what this looks like with your own numbers, we can run a simple comparison: diesel fridges versus Endurance, using your litre figures, your trailer count and your replacement cycles.

This can give you a clear view of what happens to your costs if all of your next fridges are diesel, and what changes if some of them are not.

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