fb Fuel Delivery for Businesses Across Southern Ontario | Dowler Karn

Fuel is an aspect of daily life – at home, on the farm, on the road, and at work.

Whether you need >HEATING OIL for your home furnace, DYED-DIESEL fuel for your farm equipment, or DIESEL FUEL for one generator or an entire fleet of vehicles – Dowler-Karn has the fuel solution and the service to meet your needs.

Plus, we offer quick and convenient 24-hour Fuel Access Centres at 9 locations throughout Southwestern Ontario.

For added convenience, we have automatic and tank-monitoring delivery options available for our fuel products.

Diesel Exhaust Fluid (DEF) – to meet your needs, available in jug, drum, or tote.

Automatic Delivery

You can count on worry-free delivery from Dowler-Karn.

Our Automatic Delivery is one of the most popular services we offer.

Our delivery system is based on “degree days”, which means we deliver energy based on outside temperatures. In other words, we know with a long spell of cold weather, you will use more fuel to heat your home or barn. This method makes sure we keep you topped up. Typically, furnace oil customers will see a Dowler-Karn delivery truck about six times per winter.

Tank Monitoring

Customers whose operations are heat critical or who are large volume customers may find tank monitoring to be the best solution.

This is one way Dowler-Karn will remove the worry about the level of fuel in your tank. For more information, contact a Dowler-Karn Branch near you!

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For All Your Fueling Needs:

farmer climbing onto tractor

Agricultural & Commercial Fuel Delivery

Many of our products that our agricultural and commercial customers use daily are:

  • Coloured Diesel Fuel (Off-road use);
  • Low Sulfur Clear Diesel Fuel (On-road use);
  • Regular Unleaded Gasoline;
  • Mid Grade Unleaded Gasoline;
  • Supreme Unleaded Gasoline;
  • Ethanol Gasoline;
  • Coloured Furnace Fuel;
  • Tobacco Curing Oil
  • DEF
residential house heated by fuel delivered from dowler karn

Residential Fuel Services

Many of our customers use furnace fuels for home heating appliances as well as domestic hot water heaters.

driver filling their car with fuel from one of our 24-hour fuel centres

24-hour Fuel Access Centres

An ideal and convenient solution for people and businesses on the go.

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transport truck driving with def from dowler karn

About DEF

What is DEF?

Diesel Exhaust Fluid was created by equipment manufacturers to meet Tier 4 final emission standards. Injecting DEF into the diesel engine exhaust system helps emission reduction, by breaking down particulate matter and nitrogen oxide. DEF is 32.5% synthetic urea and 67.5% de-ionized water.
DEF is: non-toxic, non-polluting, non-flammable, non-hazardous, stable, and colorless. The downside is that it is corrosive to most metals and coatings. Anyone who has accidently spilled DEF on their truck will tell you that is true, so be extra attentive when adding DEF do your vehicle.

DEF is susceptible to evaporation, so make sure to tightly close lids to protect against contamination and evaporation.

Can DEF freeze?

During vehicle operation, SCR systems provide heat to the DEF tank and lines. The system thaws DEF rapidly and keeps it flowing to the after-treatment system, regardless of the outside temperature.

What if DEF is left in my vehicles over the winter?

Diesel Exhaust Fluid is formulated with 32.5% urea and 67.5% de-ionized water. In storage, or when the engine is not in use, DEF will freeze at 12°F (-11°C). At this concentration level, the urea and the water freeze and thaw at the same rate – ensuring you always have the correct amount of each. Engines with SCR are specifically programmed for optimal performance at this ratio.

Like any water-based fluid, DEF expands when it is frozen.


In cold weather, when the operator shuts the vehicle down, waiting 60 seconds before turning off the battery will allow the fluid to drain back out of the hoses and into the DEF tank.

As always, consult your OEM user manual for specific guidelines on DEF usage requirements. If you have any questions, give us a call and we will gladly help you out!

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