Can You run a Diesel Engine on Vegetable Oil?

Can You run a Diesel Engine on Vegetable Oil?

While vegetable oil can run a diesel engine for a short time without issues, using it regularly can cause problems and damage the engine.

Unlike biodiesel, straight vegetable oil is not recommended as a long-term fuel for vehicles.

An image illustration if You can run a Diesel Engine on Vegetable Oil
Can you run a Diesel Engine on Vegetable Oil
Source: (Freepik)

Using Vegetable Oil As Fuel

Using vegetable oil in a diesel engine requires modifications.

Vegetable oil is thick and clogs the engine.

Solutions include mixing it with diesel or using a two-tank system with heating.

Significant engine changes are needed for long-term use, including new filters, glow plugs, and fuel line heating.

Conversion kits can be expensive.

Is Vegetable Oil Worth the Cost?

Converting your car to run on vegetable oil is unlikely to save you money.

Vegetable oil costs about the same as diesel and the conversion itself is expensive.

Even getting free used oil isn’t a reliable long-term solution because there’s not enough used oil to meet demand.

There might be slight environmental benefits but overall it’s not a cost-effective way to power vehicles.

How to make Diesel Engine to Run on Vegetable Oil

It involves adding a separate fuel system.

This system needs to be built with materials that can handle the corrosive nature of vegetable oil, and include heaters to keep the thicker vegetable oil flowing smoothly.

Follow these steps:

  1. Adding a separate tank for the vegetable oil and heating system to keep it flowing.
  2. Installing switching valves to allow switching between diesel and vegetable oil, and flushing the vegetable oil lines with diesel to prevent clogging.
  3. Adding an extra pump for the vegetable oil if the stock one isn’t suitable.
  4. Running new fuel lines with filters and heat exchangers for clean, warm vegetable oil.
  5. Wiring a controller or switch to manage fuel selection and adding gauges to monitor the system.
An image illustration of Running a Diesel Engine on Vegetable Oil
Running a Diesel Engine on Vegetable Oil
Source: (Freepik)


You can technically run a diesel engine on vegetable oil, but it’s not a simple switch.

Significant modifications are needed to handle the thicker vegetable oil and avoid damaging the engine.

These conversions are expensive and may not save money on fuel in the long run.

While there might be slight environmental benefits, vegetable oil isn’t a practical solution for most drivers.


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