How to Improve Gas Mileage and Bad Gas Mileage Causes

As long as you don’t drive an electric car, your fuel economy will be of the utmost on your mind. Heck, you are probably here because you ran an internet search for the entry “how to improve gas mileage.” You also probably asked the question, “why is my car using so much gas all of a sudden?”. The thing is, these concerns are valid. What with the rising gas prices and the cash-strapped economy and all? It is easy to understand how getting the most from your tank of gas helps your budget right now.

So now that you are here, what next? How do you improve your car’s fuel economy so that you can reduce your gas expenses? Well, the first step would be to understand the reasons for bad gas mileage. Once you are clear on that, it becomes easier to improve your car’s gas mileage. So, let’s look at why your car has poor fuel economy issues.

How to Improve Gas Mileage

Bad Gas Mileage Causes

If you have ever asked yourself the question, “why is my gas mileage going down?” then odds are that your car has very poor gas mileage problems. And of course, there are several reasons for that. And to put these reasons in perspective, you need to understand what bad gas mileage is. So what is considered bad gas mileage? And why is it a big deal?

Bad gas mileage refers to a situation where your car consumes more gas than normal. It is a big deal because you spend more on gas, and in some cases, it is symptomatic of other issues. That said, let’s look at the reasons your car is using up more gas than necessary.

Incorrect Tire Pressure

Your car tires have an optimal pressure that they are supposed to function at. Anything below or above that optimal tire pressure will affect the fuel economy of your car. The optimal tire pressure for your car is often written somewhere on the inside of the door on the driver’s side.

Bad O2 Sensors and Faulty Air Filters

Your car has several oxygen sensors that measure the car’s air intake and emissions and balance the air/fuel mix that powers the engine. A bad oxygen sensor will significantly reduce your car’s gas mileage because the O2 sensor will no longer balance the mixture. The same principle applies to the air filters, which are responsible for supplying clean air. Without the right amount of clean air, the car’s gas mileage will also be affected.

Bad Spark Plugs

Your car’s spark plugs are crucial to the engine’s combustion process. A bad spark plug will greatly affect your car’s gas mileage because the combustion will not be efficient. This will cause the engine to consume more gas.

Fuel System Issues

Your car’s fuel system is comprised of components like the fuel injector and the fuel filter. The fuel injector transmits fuel into the engine while the fuel filter ensures that clean fuel gets into the engine. So a bad fuel injector affects the amount of fuel that gets into the engine. On the other hand, a bad fuel filter will reduce the amount of gas getting into the engine and cause you to throttle the engine more. Both situations will negatively impact your gas mileage.

The Car’s A/C Unit

The engine powers your car’s air-conditioning unit, besides other basic engine operations that consume a lot of gas. When you add the toll of the car’s A/C unit on the engine, it means that more gas is being expended, leading to bad gas mileage. Indeed, constant A/C usage is one of the main causes of poor fuel economy causes.

A Faulty Exhaust System

Your car’s exhaust system is comprised of various components like the exhaust pipe, the O2 sensors, the muffler, and the catalytic converter. Any of these components can cause bad gas mileage, especially if your car has a bad catalytic converter.

The Wrong Engine Oil

Did you know that using the wrong engine oil will significantly affect your gas mileage? Well, it does, as strange as that might sound. If the weight and type of oil are not the right, it will affect engine performance and gas mileage. 

The Way You Drive

One of the primary excessive fuel consumption causes for your car is the way you drive. If you drive your car like a NASCAR driver, you are likely to have bad gas mileage. All that quick acceleration and excessive revving of the engine will burn more gas, leading to bad gas mileage.

Unnecessary Idling

Keeping your car idling for long has the potential to cause bad mileage. Ideally, it would be best if you did not let your car idle for more than 45 seconds. Your car does not need that long to warm up, and you are wasting your gas when you let it idle for other reasons.

modifications to increase mpg

How To Improve Gas Mileage

Now that you know why your car has bad gas mileage, it becomes easier to know how to increase car mileage. Thankfully, it is easy to understand how to improve gas mileage mechanically. All that you need to do is to reverse the causes of bad gas mileage. In some instances, you might have to make some modifications to increase mpg. By and large, improving your gas mileage is an essentially inexpensive affair that benefits you in the long run. Here are some steps to take if you are looking to improve your gas mileage.

Shed Some Weight

Not you. Your car. Get rid of some of the excess weight on your car. You want to keep your car as “lean” as possible. By this, we mean that your car should contain only the essentials because any extra weight tells on the gas mileage. Take away all the extra stuff like your soccer cleats, cargo boxes, and even roof racks if they do not serve any particular purpose. The extra stuff inside the car puts additional weight and makes the engine work a lot harder to move.

External things like roof racks and cargo boxes increase wind resistance and slow the car. In both cases, more gas is consumed since the engine does more work. When you reduce the weight of the car, you will be able to improve gas mileage significantly. It is one of the tricks you need to master if you are thinking of how to improve gas mileage in a truck or car.

Reduce Idling To a Minimum

By now, you know that idling causes your car engine to consume more gas than it would when restarting. You may not know that when your car is idling, it pollutes the atmosphere much more than it would when the car is in motion. So reduce the idling to the barest minimum, especially when you are looking for how to increase fuel efficiency and reduce emissions. Modern cars now have the stop-start feature that shuts down the car engine when it comes to a stop and automatically restarts it once the driver releases the brakes.

Change Your Driving Habits

Did you know that your car begins to lose fuel efficiency after it gets to 45-50 mph? From that point on, the car continues to lose more gas as you continue to accelerate. Add hard braking to the equation, and you have a car that simply gulps gas. Why? Driving at very high speeds increases the amount of gas the car consumes. On the flip side, when you stay within the speed limit, your chances of improving gas mileage increase. Different cars have speeds at which they are the most fuel-efficient. However, most cars are not fuel-efficient after 6omph. So except you are in a car race, it makes no sense to be moving at high speeds.

Maintain Proper Tire Pressure

Do this and watch your gas mileage improve. The proper tire pressure is great for your car’s gas consumption. When the tires do not have the required tire pressure, the car needs more engine power to move. This is because of the increased rolling resistance, which requires increased engine power before the car moves. With increased demands on the car engine, the gas mileage is reduced. Maintaining the proper tire pressure eliminates the rolling resistance that increases the energy demands of the vehicle.

Regular Car Maintenance Is Key

Regular car maintenance increases your car’s efficiency because you get to replace faulty components that make it less efficient. There is a reason why you advised us to stick to a maintenance schedule. Regular car maintenance points out parts to replace to improve gas mileage so that the combustion in the engine is more effective. For example, when you change air cleaner, or your car has a clean catalytic converter and clean fuel injectors, your fuel system becomes more efficient. This has the effect of improving your gas mileage.

Stick to the Recommended Engine Oil

You should only use the recommended engine oil for your vehicle. Using anything different will affect the engine’s performance and cause it to use more gas. Ensure that you always use the right engine oil. Even when you get an oil change, ensure that it is the right engine oil.

Use the Right Fuel Grade for Your Vehicle

Applying the tips above will not save you as much as possible if you use the wrong grade of gas for your vehicle. Your car has a recommended gas grade that ensures optimal engine operations and offers you the best gas mileage possible. When you use an incorrect quality, your engine functions change, and more gas is consumed.

how to increase fuel efficiency and reduce emissions


What Affects Gas Mileage in A Car?

A host of things. One of them is aggressive driving which is a major culprit. Excessive idling is another one that decreases gas mileage and increases pollution too. Having extra weight on the car affects a car’s gas mileage too. Others include excessive use of the a/c unit, a faulty exhaust system, wrong engine oil, bad fuel system, incorrect tire pressure, bad O2 sensors, a failed air filter, and bad spark plugs, to mention a few.

Does Revving Your Engine Waste Gas?

It all depends. “Revving” your car increases the revolutions per minute and increases the supply of gas to the engine. So if the car has an engine built to run at increased revolutions, no, you won’t waste gas. But if your car does not have such an engine, you might be wasting gas especially if the car is not in motion.

What Is The Best Speed For Gas Mileage?

It depends on the car and its engine. For most cars, it is between 55-65mph going by a submission by The Energy Saving Trust.

Does Driving Slower Save Fuel?

There are two sides to this. When you are at high speeds, your car consumes more energy since it requires more power to overcome the drag that comes with moving at high speeds. Yet when you move slowly, you take longer and consume more fuel. So it all depends on the type of car and the way it is built.

Is It Better To Store A Car With A Full Tank Of Gas Or Empty?

If you can afford it, it is better to store a car with a full tank. When the tank is empty, it gets filled with air that has water vapor in it. This water vapor can cause the fuel tank to rust and depreciate over time. When you eventually put some gas in the tank, the water vapor mixes with the gas and makes it less pure, thereby causing combustion problems. Another effect of driving with an empty tank is that it will affect the lifespan of your fuel pump.

Final Words

Knowing how to improve gas mileage is imperative, especially with the state of the economy and the rising gas prices. Thankfully the steps required to do that are not very expensive, and the results last for long. The most costly tip might just be using aftermarket parts to improve fuel economy when implementing car checkups. Once you can stick to the tips described in the article, you will increase your gas mileage and save some money on gas expenses.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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