Commercial diesel terminology can describe a fuel’s intended use, technical specification, biofuel content or duty status. DERV, EN 590 and B7, for example, can all refer to different characteristics of the same road diesel.
Gas oil and HVO are separate products with their own standards, restrictions and compatibility requirements. Understanding how these terms relate can help businesses confirm that the fuel they order is appropriate for their vehicles, machinery and operations.
How DERV, EN 590 and B7 relate
DERV stands for Diesel Engine Road Vehicle. It is the fully duty-paid white diesel used by road-going diesel vehicles, including HGVs, vans, coaches and cars.
Road diesel supplied in the UK must comply with BS EN 590. EN means European Standard, while 590 is the number assigned to the standard for automotive diesel. It sets requirements and test methods covering the properties of the fuel.
B7 describes the amount of biodiesel the fuel can contain. Diesel displaying the B7 label can include up to 7% Fatty Acid Methyl Ester, commonly known as FAME.
A single road diesel can therefore be described in all three ways:
- DERV describes its intended use in road vehicles.
- EN 590 identifies the standard it meets.
- B7 indicates that it may contain up to 7% FAME.
The UK Government states that standard diesel sold in the UK can contain up to 7% biodiesel. Operators should still follow the fuel specification given by the vehicle or equipment manufacturer.
Gas oil and red diesel
Gas oil or Red Diesel is used in certain machinery, heating and power-generation applications. Red diesel is fuel that has been chemically marked and dyed to show that it has been supplied at a reduced rate of fuel duty.
The red colour identifies its duty status. It does not, by itself, describe the quality or performance specification of the fuel.
Red diesel can only be used in vehicles, machines and appliances that qualify under the current rules. Changes introduced in April 2022 removed entitlement from a number of sectors and applications.
Permitted uses include certain activities connected with agriculture, horticulture, forestry, rail transport, travelling fairs and circuses, amateur sports clubs and golf courses. There are also provisions covering some non-commercial heating and electricity generation.
Eligibility depends on both the type of vehicle or machine and the purpose for which it is being used. A machine may qualify while completing one activity but not another.
Businesses should check the current HMRC guidance on using rebated fuels when confirming their entitlement. HMRC states that owners and hirers are responsible for ensuring the correct fuel is used.
HVO and the EN 15940 standard
Hydrotreated Vegetable Oil, usually shortened to HVO, is a paraffinic fuel manufactured from renewable raw materials. It is commonly described as a renewable alternative to conventional diesel and is generally produced to the EN 15940 specification.
HVO can be used in many existing diesel engines without mechanical modification, but compatibility depends on approval from the vehicle or equipment manufacturer. This should always be confirmed before introducing the fuel.
Where approved, HVO can be used in applications such as commercial vehicles, agricultural machinery, construction equipment, generators and industrial machinery.
HVO may allow a business to reduce the lifecycle greenhouse gas emissions associated with operating existing diesel-powered assets. The reduction available depends on factors including the raw materials used, how the fuel is produced and its supply chain.
HVO also offers good storage stability and cold-weather performance. These characteristics can make it particularly relevant to businesses storing fuel for standby generators, seasonal machinery or equipment that is not used continuously.
Businesses considering HVO should confirm:
- That the vehicle or equipment manufacturer approves EN 15940 fuel
- That the supplied product meets the required specification
- How the fuel will be stored and dispensed
- The sustainability information available for the product
- Whether existing fuel will remain in the tank during the change
Read our guide to HVO and diesel for a more detailed comparison.
Why diesel specifications account for cold weather
Cold temperatures can affect the way conventional diesel flows. Wax crystals can form as the fuel cools, potentially restricting its passage through a fuel filter.
BS EN 590 includes different climate grades with cold-temperature requirements. This enables diesel supplied at different times and in different locations to be suited to the expected conditions.
Fuel that remains in storage for an extended period requires particular consideration because it may have been delivered under an earlier seasonal specification. This can be relevant to businesses operating standby generators, emergency equipment or machinery with low fuel turnover.
Businesses storing conventional diesel should discuss their operating conditions and expected turnover with their fuel supplier, particularly when equipment must remain available during colder weather.
Are DERV, red diesel and HVO interchangeable?
These fuels may be suitable for similar types of diesel engine, but that does not make them interchangeable in every situation.
DERV is fully duty-paid fuel intended for road vehicles. Red diesel is restricted to qualifying machines and uses. Its physical suitability for an engine does not provide legal entitlement to use it.
HVO is produced to a different fuel standard from conventional EN 590 diesel. Its use should therefore be based on the vehicle or equipment manufacturer’s approval for EN 15940 fuel.
Before changing products, businesses should confirm the required fuel specification, manufacturer approval and any applicable duty restrictions. The contents of the existing storage tank should also be identified before another fuel is introduced.
Managing different fuels on the same site
A business may require DERV for road vehicles, red diesel for eligible machinery and HVO for approved equipment. Where several products are stored on one site, clear identification becomes particularly important.
Tanks, pumps and filling points should be labelled so that staff can distinguish between the products available. Rebated fuel must be kept from entering vehicles or machinery that are not entitled to use it.
Delivery records and invoices also provide an account of the fuel purchased. HMRC requires registered dealers in controlled oil to keep specified records relating to supplies of rebated fuel.
Regular communication between site teams, purchasing departments and the fuel supplier can help ensure that delivery arrangements reflect changes in demand, equipment and available tank capacity.
For sites requiring more responsive deliveries, Oilfast Express can also provide a flexible fuel supply option when operational requirements change or additional fuel is needed at short notice.
Understanding your commercial fuel requirements
The main terms can be summarised as follows:
- DERV is fully duty-paid diesel intended for road vehicles.
- BS EN 590 is the standard covering automotive diesel.
- B7 indicates that diesel may contain up to 7% FAME.
- Red diesel is marked fuel supplied at a reduced rate of duty and restricted to qualifying uses.
- HVO is a paraffinic alternative generally produced to EN 15940 and subject to manufacturer approval.
For commercial fuel buyers, the priority is to confirm the required specification, understand any restrictions and ensure the correct product is delivered to each vehicle, machine or storage tank.
OilMaxx supplies DERV, gas oil and HVO to businesses across England. Contact our team to discuss your commercial fuel requirements and arrange a reliable delivery.