Written by: Jen Wagner
Last updated: February 12, 2022
No one enjoys finding a mechanical issue in their vehicle. And depending on the repair, it can drain your budget and patience if you aren’t prepared. But what’s more frustrating is realizing you’re the cause of the problem in the first place. For instance, maybe you grabbed the wrong pump at the gas station and filled your car with fuel that’s not intended for your vehicle. Could this innocent mistake really turn into a costly repair?
Breaking Down Your Options at the Pump
Distractions can happen at any moment, whether it’s a phone call, a crying baby, or just plain exhaustion and brain fog. But what happens when it causes you to fill your tank with the wrong gas? To better understand the effects, you first need to know the different options at the pump and their associated grade levels.
In the US, you can choose from three grades of gas based on octane level. These include:
- Regular: This is the lowest octane fuel and is generally labeled 87.
- Midgrade: This level is considered the middle-range octane fuel and will likely be labeled 89 or 90.
- Premium: This is the highest octane fuel and can be labeled 91 or 94.
Different companies may use other grade names for their gasoline, like regular vs. unleaded, super vs. plus, and super-premium. Regardless, the associated number on the pump refers to the overall octane rating, which measures fuel stability. In order to correctly operate, an automobile’s engine must have the minimum octane level so it doesn’t ping and damage the engine. But what happens if you accidentally fill your tank with a grade you don’t usually use? Read on.
Accidentally Filling Your Tank With the Wrong Gas
Ultimately, how your car reacts to the incorrect fuel type will depend on the grade it takes and the option you mistakenly choose. Consider the following scenarios and whether you should anticipate any wrong gas in car symptoms:
- You fill up with premium-grade instead of regular or vice versa…
A common misconception regarding automobiles and fuel is that premium gas increases a car’s performance and extends the engine’s lifespan. In reality, the only thing premium will affect is your wallet because it is much more expensive. Mistaking it for regular unleaded fuel should not affect your vehicle. So unless your car has a smaller turbocharged engine or is a higher-performance vehicle that requires higher octane, there’s no reason to buy it. But using it won’t hurt your car.
Likewise, your engine will probably not see any lingering effects if you accidentally fill your tank with regular, even if the manufacturer recommends premium. If anything, you may hear rattling or see a decline in your car’s performance and fuel economy. While the latter two aren’t problematic, you should stop driving and call your mechanic if you start hearing strange noises. These sounds could indicate that the fuel isn’t burning correctly. But if nothing happens, continue following the recommended guidelines when you fill up your tank the next time to protect your engine and your car warranty.
- You grab the diesel instead of regular gas…
Gas stations usually mark diesel pumps with a different color and larger nozzle. Because of the size difference, fitting the nozzle into the opening of a regular car’s gas tank is more complicated to do. Still, it’s not impossible. Therefore, if you accidentally fill your car with diesel, the engine will probably not start. But if it does, you might quickly see puffs of black smoke coming from the tailpipe. This is a warning sign that something is wrong.
To avoid any damage, immediately turn off the engine as soon as you see smoke. Contact a towing service to bring it to an auto repair shop and have a skilled mechanic drain the gas tank and flush the fuel lines. Unless you have an active car warranty covering the tow fee, it will be your responsibility to pay for the transport and the draining/flushing services. Unfortunately, draining a gas tank can cost between $500-$1,000.
- You fuel your diesel tank with unleaded …
Putting regular gas in a diesel tank can lead to extensive and costly damage, especially if you start the car after filling up. Since unleaded fuel removes the lubricating element of diesel fuel, damage to other parts like your fuel system and the engine can occur. Again, you will know something is wrong if you see black smoke coming from your tailpipe or you feel the engine knocking.
As soon as you detect a problem or realize the mistake, turn off the engine and call for a tow to your auto shop. A skilled mechanic can drain the tank, flush the fuel lines, and hopefully prevent further damage, including protecting the engine.
Protecting Your Car and Budget
Unfortunately, accidents can happen to anyone at any time. But being proactive and preparing for a breakdown before it occurs is a great way to save yourself money and unnecessary stress. With an active extended car warranty, you can select the best plan for your circumstances and budget, including one that has 24/7 emergency roadside assistance. This way, you can access a tow truck whenever you need it. Explore our extended warranty provider reviews to find a vehicle protection plan that works best for you.
