Putting the wrong gas in your car can cause various problems, depending on the type of fuel and your vehicle. Here are some possible scenarios and what you should do if you put the wrong gas in your car:

• Diesel in a gas car: Diesel fuel nozzles tend to differ from regular gas nozzles at a gas station, so this mix-up is a bit hard to make, but mistakes do happen. If you realize you’ve made the mix-up, stop driving the car. Parking and turning the car off will help to limit the damage. Otherwise, the car will eventually use up the gas in the tank and eventually shut down, since regular gas engines cannot combust diesel. Youll need to drain your gas tank and fuel lines, which is a job best left for a mechanic. Contact a towing service or Roadside Assistance for a tow to the mechanic.

• E85 in a non-flex-fuel car: E85 is a type of gas with a much higher blend of ethanol. Cars that are labeled as flex-fuel can switch between this type of gas and regular gasoline without issue, but if your car is not flex-fuel, you might notice some issues. The check engine light will most likely illuminate, but you can top off the rest of your tank with regular gasoline and ride it out. A one-time mix-up with E85 gas shouldn’t cause any long-term damage.

• Lower octane fuel in a car that requires premium gas: Using lower octane fuel in a vehicle that requires premium gas could cause some serious internal damage. You’ll most likely notice the spark knock (a sort of high-pitched pinging or rattling noise). Luckily, the engine computers can adjust the timing to limit the amount of damage caused, but you’ll definitely notice lower fuel economy and reduced performance. A one-time slip-up likely won’t lead to major damage, but you shouldn’t make a habit out of it. If you don’t realize your mistake until later, continue to periodically top off the tank with regular gas as you drive around and burn fuel. Luckily, a one-time mishap usually doesnt lead to any long-term damage or expensive maintenance.

• Mixing different types of gas: Mixing different types of gas, such as unleaded and premium, is generally not harmful to your car. However, if you mix diesel with gasoline, it can cause your engine to fail, costing you thousands of dollars to replace depending on your vehicle.

If you put the wrong gas in your car, you should take action immediately to protect your vehicle from severe damage. Here are some steps you can take:

• Stop driving the car: If you realize you’ve put the wrong gas in your car, stop driving the car immediately to limit the damage[[5]](https://www.statefarm.com/simple-insights/auto-and-vehicles/what-to-do-if-you-put-the-wrong-fuel-in-a-ca...