# Wrong Fuel in Farm & Mining Machinery: Tractors, Excavators & Generators > Wrong fuel is not just a car problem. Tractors, excavators, skid steers, generators, and other heavy machinery get misfuelled regularly, and the consequences are often worse because the fuel systems are built to tighter tolerances and the repair bills are… > URL: https://wrongfuelhelp.com.au/blog/wrong-fuel-tractor-farm-machinery/ > Last modified: 2026-10-10T12:12:19+00:00 Wrong fuel is not just a car problem. Tractors, excavators, skid steers, generators, and other heavy machinery get misfuelled regularly, and the consequences are often worse because the fuel systems are built to tighter tolerances and the repair bills are significantly higher. If you work in farming, mining, or construction across the Hunter Valley or regional NSW, this is worth reading before it costs you a machine and a day of lost productivity. Call Now ## Why Wrong Fuel Happens More Often With Machinery Than Cars With a car you pull up at a clearly labelled bowser. “When it comes to using machinery that’s a whole different ball game and that’s where the mistakes come in. Bulk fuel in tanks, drums or jerry cans is stored at most farms and mine sites. And those containers are not always clearly marked. Someone who didn’t check could fill a jerry can that held diesel last month with petrol. Sometimes, properties with bulk tanks can have cross contamination when a delivery is placed in the wrong storage tank. Under normal circumstances, someone in a petrol vehicle could, without thinking, refuel a diesel excavator on a busy farm during harvest or on a construction site with multiple operators. Most heavy machinery does not have a misfuelling prevention device. The filler necks take any nozzle. Generators get caught out as well, Petrol and diesel versions are available and are generally filled by whoever happens to be around. ## What Happens When Petrol Goes in a Diesel Tractor or Excavator? Petrol removes the lubrication that diesel provides to the fuel pump, injectors and fuel rail. These parts operate under very high pressures in today’s common rail diesel engines and rely on the oily properties of diesel to lubricate themselves. Petrol causes metal on metal contact and rapid wear . Replacing a high pressure fuel pump & injectors on a tractor or excavator isn’t cheap, thousands easily. On bigger machines it can cost more to simply fix the fuel system than to buy a new car. The important thing is whether the engine was started. If the petrol is just sitting in the tank, a [drain and flush](https://wrongfuelhelp.com.au/blog/fuel-drain-flush-service-cost-australia/) will sort it. If the engine was run, the contamination is spread with every minute. ## Wrong Fuel in a Generator: Diesel vs Petrol Mix-Ups Generators add confusion as there are both fuel types and they often look the same from the outside. Putting petrol in a diesel generator will knock, overheat and stall. A petrol generator filled with diesel will smoke heavily and struggle to start. In either case, turn off the machine, drain the tank, flush the system and refill with the proper fuel. With smaller portable generators, it’s simple. With bigger site generators that are connected to the fuel supply lines it gets more complicated. ## What to Do If You Have Put the Wrong Fuel in Your Machine The steps are the same regardless of whether it is a tractor, excavator, loader, or generator. - Stop the engine immediately if it is running. - Do not attempt to restart it. - Isolate the machine so nobody else tries to start it. On a busy site, tag the ignition. - Call a mobile fuel drain service to come to the location, drain the [contaminated fuel](https://wrongfuelhelp.com.au/services/contaminated-fuel/), and refill with the correct fuel on the spot. [Wrong Fuel Help](https://wrongfuelhelp.com.au/) provides on-site fuel drain and recovery for machinery across Newcastle, the Hunter Valley, Central Coast, and regional NSW. Call **0432 553 905** any time. ## The Cost of Getting It Wrong vs Getting It Drained Almost always a fuel drain before starting the engine will save the entire fuel system. Running on the wrong fuel for as little as ten minutes can require replacement of injectors, fuel pump, filters and lines. That repair can run from $5,000 to $20,000 or more on heavy diesel machinery. Fuel drain is a few hundred to a couple of thousand. The engine runs on five to ten times that amount. ## FAQs ### Can petrol damage a diesel tractor engine? Yes. Petrol strips the lubrication diesel provides to the high-pressure fuel pump and injectors. If the engine is run on petrol, these components can fail rapidly. If caught before the engine is started, a drain and flush will prevent damage. ### Will a generator run on the wrong fuel? It may run briefly but it will run poorly. A diesel generator on petrol will knock, overheat, and stall. A petrol generator on diesel will struggle to start and smoke heavily. In both cases, stop the machine and drain the fuel before attempting to use it again. ### Can you drain wrong fuel from an excavator on site? Yes. A mobile fuel drain service can come to the farm, mine site, or construction yard and drain the contaminated fuel on the spot. There is no need to transport the machine to a workshop in most cases. ### Is wrong fuel in machinery covered by insurance? It depends on your policy. Some farm and commercial equipment policies cover misfuelling as accidental damage, but many do not. Check with your insurer. Either way, a fuel drain is significantly cheaper than a full fuel system rebuild. ## Wrong Fuel in Your Machinery? If you have put the wrong fuel in a tractor, excavator, generator, or any other machine, do not start the engine. **Call [Wrong Fuel Help](https://wrongfuelhelp.com.au/) on 0432 553 905.** Available 24/7 across Newcastle, Hunter Valley, Central Coast, and regional NSW. We come to the farm, the site, or wherever the machine is.