Should You Top Off Your Gas Tank? | Scott's Fort Collins Auto

Should You Top Off Your Gas Tank?

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There’s all sorts of rumors about how you should properly fill your vehicle with gas. Is it bad to top of your gas to the nearest dollar at the pump? Should you top it off regularly to prevent your fuel level from ever getting low? In this article, we’re discussing what you should really do when it comes to making sure your car has fuel. 

What to Know About Fuel 

You may not think much about the fuel (gas) you put into your car, but it never hurts to learn more about it. Here is what Allstate recommends you know before fueling up: 

Where is the gas cap? 

When you look at the fuel gage on your dash, there will be an arrow triangle near it. This triangle will indicate which side of the vehicle your gas tank is on. If the arrow is pointing to the left, the gas cap is on the left of the car. If it’s pointed towards the right, then it will be on the right side of your car. 

What happens if you use the wrong kind of fuel?

When you pull up to a gas station there are usually a few options for what you can put into your tank. If you mix up fuel types at the pump, it can result in a number of major engine problems.

If you put regular gas into a diesel engine, do not start the engine. You will need to have your vehicle towed to a mechanic, the gas will need to be drained, and then next steps can be determined. This is because diesel engines ignite fuel using heat, whereas gasoline engines use spark plugs to ignite the fuel. 

When diesel is put into a normal gasoline engine, it could ruin parts of your fuel system. While it may not destroy the engine, it could negatively affect your fuel injectors or your fuel pump. This is because diesel is thicker and more dense than regular gasoline, which makes it difficult for the fuel pump to move it through the system. 

What about E85 fuel?

Flex-fuel cars run on E85, which is a mix of 85% ethanol to 15% gasoline. If your car isn’t a flex-fuel vehicle and you add E85 to your tank, you may notice a reduced performance and gas milage. Your check engine light may even come on as well, but it shouldn’t damage the engine. To correct this, it’s recommended to top off your tank with regular gas several times. Once all E85 has left your engine, the check engine light should turn off. 

What’s the difference between premium and regular unleaded gasoline? 

Fuel contains oxygen that helps keep gas from prematurely igniting in the engine. An octane grade or rating of gas is based on how much oxygen is in the fuel. Unleaded gasoline is fuel with an octane rating around 87. Premium fuel has a higher octane level. While most cars run on unleaded fuel, using premium grade fuels typically won’t affect your engine’s performance.  

Should You Top Off Your Gas Tank?

When it comes to how often you should be filling up your tank, you should refrain from topping it off with small amounts of gas. While it may seem convenient, gas topping can damage your car’s vapor collection system, which is made to reduce harmful emissions. Since these systems manage fuel vapor, overfilling the tank can cause liquid gas to enter the charcoal canister or carbon filter, which is made only for vapor. Gas in the system can affect your car’s performance and damage the engine. 

Keep Your Car Running with Scott’s Auto

If you are concerned that you just put the wrong type of gas in your car or notice your car not running as efficiently as it should, stop by Scott’s Auto. With four convenient locations in Colorado, our teams are here for you. To learn more about us, click here

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