Maybe you were tired. Maybe it was dark. Maybe there was no line at that pump. No matter. Whatever excuse you’re telling to make yourself feel better, you now have diesel in your gas tank and soon to have diesel in your gas engine. Fuel is fuel, right? Just how bad could it be?
How Bad is Diesel in Gas Engine?
Not to put too fine a point on it, it’s bad. Both diesel and gasoline are refined versions of crude oil, but they are refined differently and are combusted differently inside an engine. Velveeta is fine for queso dip, but it’s not exactly a welcome addition at a wine pairing.
Fortunately, the sellers of automotive fuels have taken steps to make it hard to put the wrong pushwater into your vehicle. Diesel pump handles are green, and the nozzle is larger. It probably won’t fit in your tank opening and, if it does, it won’t insert the whole way. In other words, unless you’re driving a diesel car, it’s really hard to make this mistake, at least without making a huge mess. Hopefully, you’re ruined shoes will stop you from going the whole way and ruining your engine.
But I Still Managed to do it Somehow…
Now the question becomes how bad is bad. As with almost every question, the answer is “that depends.” It all comes down to how long the engine runs with the wrong fuel trying to run it. The best case scenario would be discovering the error before starting the car. In this event, have the car towed and have the tank emptied and flushed. If none has made its way to the engine, you should be golden.
If you have driven the car for only a short while before your discovery, all may still not be lost. Shut it down and tow it to a garage. You’ll need to do this without passing go or collecting $200 which is unfortunate as the mechanic will probably collect $400 to $1500 dollars from you to flush the fuel tank, lines, injector and pump. Not cheap, but cheaper than a new engine.
Be Careful Not to Get Diesel in Gas Engine
It doesn’t take long for diesel fuel to destroy a gasoline engine. Diesel fuel is designed to combust under pressure, not spark. This scenario causes the engine to run rough, rough enough to possibly lose compression, damage valves and bend pistons. If diesel does accidentally find its way into your tank, don’t run the engine and, if it is running, shut it down immediately. Hopefully a system flush done in time will let your engine live to see another day.