Updated October 2026
If you run trucks and off-road equipment from the same yard, you have probably asked: can you mix dyed and clear diesel? The short answer for Ontario is no. Mixing coloured fuel with any other fuel without the Ministry of Finance’s authorization is an offence, and putting dyed diesel in a licensed vehicle can lead to a fine and a tax penalty.
Here is what the rules say, what the penalties are, and how to keep both fuels on your site without problems.
What’s the Difference Between Dyed and Clear Diesel?
Both are the same fuel. The difference is tax and how you are allowed to use it.
- Clear diesel (road diesel) is taxed. It is the fuel for licensed on-road vehicles such as trucks, vans and buses.
- Dyed diesel (coloured or off-road diesel) is tax-exempt and has a red dye added. It is for eligible off-road use, such as construction equipment, farm machinery and generators.
See our dyed and clear diesel delivery page for how we supply both.
Can You Mix Dyed and Clear Diesel?
Chemically, the two fuels will blend. Legally, you should not do it. Ontario’s rules say you must not mix or combine coloured fuel with any other type or grade of fuel unless the Ministry of Finance authorizes it, and blending coloured fuel with another product without authorization is an offence.
Mixing also creates a practical problem. Once dyed diesel goes into a tank, the dye stays in the fuel system. If that tank feeds a licensed vehicle, an inspection can find dye even if most of the fuel was clear.
Is Dyed Diesel Illegal in Ontario?
No. Dyed diesel is legal for eligible off-road use. What is not allowed:
- Using it in any motor vehicle licensed under the Highway Traffic Act. This includes vehicles used mainly for farming, construction, forestry or mining.
- Using it in a vehicle or boat that is mainly used for pleasure or recreation.
There is one common exception for fleets. Auxiliary equipment on a truck, such as a refrigeration unit, can run on dyed diesel if it has its own separate tank that is not connected to the vehicle’s fuel tank. If the equipment draws from the same tank as the engine, you must use clear diesel.
What Is the Fine for Using Dyed Diesel in Ontario?
According to the Ontario Ministry of Finance:
- A first offence for using coloured fuel improperly carries a fine of $465.
- The Ministry can also assess a penalty equal to three times the tax that would have been payable on clear fuel, and ten times the tax for later offences.
- Paying a fine or penalty does not cancel the tax you owe.
- Refusing a fuel inspection can lead to a fine of up to $1,000 for each refusal.
- Tampering with coloured fuel, seals or labels can bring fines of up to $1,000,000, up to two years in prison, or both.
Fuel inspectors check vehicles on Ontario roads, so a mix-up at the yard can turn into a real cost. Amounts can change, so check the Ministry of Finance coloured fuel page for the current rules. This article is general information, not legal or tax advice.
How to Store Both Fuels on One Site
- Keep dyed and clear diesel in separate tanks, with no shared lines.
- Label every tank and nozzle clearly.
- Make sure drivers and operators know which equipment takes which fuel.
- Tell your supplier which tank is which before each delivery.
Fleet managers can use our pre-delivery checklist to get a site ready.
Dyed and Clear Diesel Delivery in Toronto
Lambert Oil delivers both dyed and clear diesel to job sites, farms, fleet yards and generators across Toronto and the GTA, and to more than 200 municipalities across Ontario. We can supply sites that need each type in separate tanks. Most orders arrive within one business day, often within a few hours.
Call 416-531-1158 or request a delivery.
