Petrol in a Diesel Truck or Commercial Vehicle: What to Do Before You Start the Engine
If petrol has gone into your diesel truck, van, or commercial vehicle, do not start the engine. A quick fuel drain can help prevent expensive fuel-system damage and reduce costly business downtime.
It happens more often than you would think. A driver grabs the wrong nozzle, fills a diesel truck or van with petrol, and suddenly a vehicle that is supposed to be out earning money is sitting at a servo going nowhere. With commercial vehicles, the problem is not just the repair. It is the downtime, the missed deliveries, the jobs that do not get done, and the cost of having a vehicle off the road.
If this has just happened to one of your vehicles, here is what you need to know.
Why It Happens More Often in Commercial Fleets
Personal car: filling the same vehicle every time. In a mixed fleet business drivers are constantly on rotation. Someone who drove a petrol HiAce yesterday might be driving a diesel NPS today. Add in a new hire or someone topping up at the end of a long shift and mistakes happen.
This is common in vans and light trucks such as the Toyota HiAce, Hyundai iLoad, Isuzu NPR, Hino 300 and the Fuso Canter. The vehicles are similar in petrol and diesel versions and fuel caps are not always clearly marked.
The use of jerry cans for on-site refuelling by businesses adds another risk. A can without a label, or filled with the wrong fuel, is a mis-fuelling waiting to happen.
What Petrol Does to a Diesel Truck Engine
The damage is the same as in a diesel car but the costs are multiplied. Diesel is a lubricant for the fuel system. That lubrication is what the high pressure pump, injectors and rail depend on. Petrol takes all of it away.
In commercial diesels, these parts are larger and more expensive than passenger car equivalents. Injectors for an Isuzu NPR or Hino 300 are much more expensive. A high-pressure pump replacement can run into the thousands before you even get to labour.
If the engine wasn’t started the petrol sat in the tank and a drain will fix it. When the engine has been running, contaminated fuel has gone all round everything and the bill is going up every minute.
The Hidden Cost: Downtime
Wrong fuel is an inconvenience for a private car. For a business it is lost revenue. Delivery truck off the road means missed deliveries. If a tradesperson’s van is in the workshop then it is a non-billable day.
In most cases, when the engine is not running, a mobile fuel drain gets the vehicle back on the road in 30 to 60 minutes. That is compared to towing it to the dealer, waiting for parts and being without the vehicle for days. The difference in down time alone often makes a drain the cheaper option, even before you compare the cost of repairs.
What to Do If Petrol Has Gone in Your Diesel Truck or Van
- Stop the engine immediately if it is running.
- Do not turn the ignition on. On modern commercial diesels, the fuel pump primes the moment the key turns.
- Notify your fleet manager or workshop so the vehicle is isolated and nobody else tries to start it.
- Call a mobile fuel drain service to come to the vehicle and drain, flush, and refill on site.
Wrong Fuel Help provides 24/7 mobile fuel drain and recovery for trucks, vans, and commercial vehicles across Newcastle, Hunter Valley, Central Coast, and regional NSW. We come to the depot, the job site, or wherever the vehicle is. Call 0432 553 905 any time.
How to Reduce Misfuelling Risk Across Your Fleet
A few simple steps can prevent this from happening in the first place.
Label every vehicle’s fuel cap clearly with the correct fuel type. A bright sticker that says DIESEL ONLY is cheap and effective. Label your jerry cans the same way if you refuel on site.
Brief every new driver on the fuel type for the vehicle they are driving. Make it part of the handover process, especially for casuals and temps who may not be familiar with the fleet.
If your fleet has both petrol and diesel vehicles, consider colour-coding the keys or key tags so drivers know at a glance which fuel the vehicle takes.
Frequently Asked Questions
Can petrol destroy a diesel truck engine?
If the engine was started and run on petrol, it can cause serious damage to the fuel pump, injectors, and fuel rail. If caught before starting, a drain and flush will prevent damage entirely.
How much does a fuel drain cost on a commercial vehicle?
It depends on tank size and whether the engine was started. A drain on a light truck or van where the engine was not started is typically less expensive than a passenger car rebuild and far cheaper than replacing fuel system components.
Can you drain a truck on site or does it need to go to a workshop?
A mobile fuel drain service can come to the vehicle wherever it is. Depot, job site, servo forecourt, or roadside. No towing needed in most cases.
Who pays for a wrong fuel incident in a business vehicle?
That depends on your business insurance policy and internal arrangements. Some commercial vehicle policies cover misfuelling as accidental damage. Check with your insurer. Regardless of who pays, a quick drain is always cheaper than a full fuel system repair.
Got a Truck or Van With Wrong Fuel?
Do not start the engine. The faster the fuel is drained, the less it costs and the sooner the vehicle is back earning money.
Call Wrong Fuel Help on 0432 553 905. Available 24/7 across Newcastle, Hunter Valley, Central Coast, and regional NSW.
