At what mileage do cars start having problems?

11 Reasons Your Gas Mileage Is Getting Worse and Worse

With more and more vehicles on the road reaching high-mileage milestones, some people may be left asking “Why is my car gas mileage getting worse?” After the first 100,000 miles, what started as an EPA-rated 28 MPG car might end up being more like a 20 MPG car — or worse! The loss in fuel efficiency can not only drain your gas tank faster but your wallet too.

If you’ve noticed your gas mileage getting worse as your car ages, there are many things you can do to both save on gas and boost your vehicle’s overall fuel efficiency. Read on to understand why fuel economy drops as cars age and, more importantly, what you can do to help keep your vehicle running smoothly for many miles to come.

11 Reasons Why Your Car’s Gas Mileage Is Getting Worse

It seems like common sense that, as a car gets older, it tends to get worse and worse gas mileage. In reality, it’s more accurate to say that poorly maintained cars are more likely to have worsening gas mileage over time. In fact, drivers who stick to their manufacturer’s maintenance schedule are typically less likely to see any major dips in fuel economy over the life of their car.

One of the most simple solutions to keeping gas mileage up is staying on top of routine maintenance. Still, with so many parts to account for as your car reaches 100,000 or even 200,000 miles, keeping up with fuel-saving maintenance can be tricky — especially when you consider how other factors like hot weather can also affect fuel efficiency.

What should you look out for to make sure your car keeps chugging along like the day you bought it? Start by addressing the common problem areas listed below.

1. Clogged or Damaged Fuel Injectors

One of the most common culprits for a drop in fuel efficiency is dirty fuel injectors. Fuel injectors are the nozzles that spray fuel into each engine cylinder. A fuel injector’s spray pattern must be very precise to properly mix with air and combust inside the engine.

When a fuel injector becomes dirty or clogged, it may spray fuel inefficiently, think of a poorly pressurized shower head. This can quickly reduce the efficiency of your engine and lower fuel economy. In many cases, the fuel injector nozzles can be cleaned. Other times, the injectors may need replacing if internal damage is causing a bad spray pattern.

2. Old Engine Air Filter

Engines must suck in air to power vehicles. If your engine air filter is particularly dirty or clogged, your engine won’t be able to “breathe.” To compensate, the older engines would burn more fuel to travel at the same speed. Newer engines may perform more poorly trying to compensate for a clogged air filter.

This problem is particularly common among older cars that rely on carburetors. Engine air filters should be replaced approximately every 15,000 to 30,000 miles, but check your owner’s manual to be sure or have it inspected at your next oil change.

3. Dirty Oxygen Sensor

Whereas many older cars use carburetors to ensure the engine receives the proper ratio of air-to-fuel for combustion, all newer cars since about 1996 use oxygen sensors instead. An O2 sensor measures how rich or lean the exhaust gases are that exit your engine and sends a message to your car’s computer to adjust how much fuel enters the engine.

A dirty oxygen sensor may lead to incorrect measurements that cause your engine to burn too much fuel, lowering efficiency by as much as 40% according to Edmunds.

Faulty oxygen sensors are one of the most common causes of a check engine light and will likely need inspecting and possibly replacing before the 100,000-mile mark. Thankfully, O2 sensors are relatively affordable to replace, helping you save on gas and keep your vehicle’s emissions in check.

4. Clogged Fuel Filter

Fuel filters block contaminants in the fuel from traveling throughout the engine where they could damage fuel injectors and other important parts. A clogged fuel filter can lower fuel pressure and cause your engine to run poorly.

For older cars especially, it’s important that fuel filters get changed approximately every two years or every 30,000 miles. If you suspect a dirty fuel filter to be the cause of your decreased gas mileage, bring your car into your local Firestone Complete Auto Care for a fuel pressure test.

5. Worn Out Piston Rings

The piston rings in your engine cylinders form a seal against the cylinder walls to create compression. When piston rings become worn out, they aren’t able to create that seal and the engine loses pressure. As a result, fuel efficiency goes out the window.

Engine oil not only helps lubricate the piston rings, it also contributes to fuel efficiency. The best solution is to make sure your car has regular oil changes with the manufacturer-recommended oil type found in your owner’s manual.

6. Bad Ignition System Parts

The ignition system includes coils, spark plugs, and wires that are responsible for combusting the air-fuel mixture in the engine. If any of these parts are malfunctioning, it may be causing the engine to misfire. A misfire occurs when the fuel in an engine cylinder does not combust. Since unburnt fuel cannot power your vehicle, this ends up wasting gas and lowering your fuel economy.

You may experience rough idling, stumbling, or an overall decrease in power from the engine if the ignition system is to blame. The most common culprit inside a failing ignition system is the spark plugs.

7. Old or Incorrect Engine Oil

There’s a common myth that older cars should use thicker engine oil to prevent leaks. The thinking goes that since internal seals and gaskets become brittle and shrink with age, thicker oil would be less likely to seep through the cracks.

Specially formulated “high mileage engine oils” can do this by using seal conditioning additives to help older seals become more flexible and do a better job sealing. In addition, the viscosity is slightly increased to help worn piston rings seal better. However, thicker oil actually creates more resistance between engine parts, which lowers fuel efficiency.

The right motor oil is essential to keeping modern engines lubricated and protected. The best thing you can do to keep your car’s gas mileage up is to perform regular oil changes with the type of oil specified in your owner’s manual. High mileage engine oils may help reduce oil leaking and oil consumption but it will take away some of the potential fuel efficiency.

8. Dirty Mass Airflow Sensor

Mass airflow sensors measure the amount of air flowing into the engine. Like an oxygen sensor, the mass airflow sensor sends data to the onboard computer to calculate the correct air-to-fuel ratio in the engine and the computer adjusts fuel injection accordingly. However, a dirty airflow sensor will cause the car’s computer to miscalculate the proper air-fuel mixture, leading to decreased fuel efficiency or even engine stall. Mass airflow sensors should be cleaned with a special cleaning spray.

9. Underinflated Tires

Low-pressure tires are a common cause of worsening MPG because an underinflated tire has increased rolling resistance with the road and a slightly smaller effective diameter. Modern cars come with a tire pressure monitoring system (TPMS) to notify drivers when their tires need more pressure, but the warning is only triggered after a significant loss of PSI. Even running five PSI below recommended pressure is enough to create drag and lower fuel economy even if the TPMS doesn’t yet display a warning.

One of the easiest things you can do to keep up fuel efficiency is to regularly check your tire pressure and top-up with air as needed. Another smart option is to use Bridgestone Ecopia tires, which are made with fuel economy in mind. Ecopia tires feature a low rolling resistance tread designed to help you save both money and fuel with fewer trips to the gas pump. While it’s best to pair Ecopia tires with other gas-saving maintenance, the fact is fuel-efficient tires go a long way towards a greener, more cost-effective ride.

10. Worn or Stuck Brakes

Not only is it dangerous to drive with worn-out brake parts, but sticky brakes could also be causing your MPG to plummet. A stuck caliper or sticky brake pads, for example, create resistance to your vehicle’s forward motion. Brake drag means your engine must constantly fight with the brakes just to move, causing fuel efficiency to drop dramatically. Be sure to check your brakes regularly — or simply bring your car into Firestone for a comprehensive brake inspection.

11. Poor Alignment

If you’ve been driving for a while with a steering wheel that doesn’t sit straight, chances are your wheel alignment is costing you money at the pump. Just like with low-pressure tires, misaligned wheels create resistance to traveling straight down the road. Constantly fighting this resistance requires more effort from the engine and hurts fuel economy. Luckily, wheel realignment is a simple fix that can be done at any Firestone Complete Auto Care location near you.

Get the Most Out of Your Gas Mileage

Whether your car needs new tires or a new fuel filter, your local Firestone Complete Auto Care technician can get to the bottom of your fuel problems and make things right. Make an appointment today!

High-Mileage Car Problems: 8 Common Issues (Explained)

Using high-mileage car can be attractive because they tend to be cheap and past their depreciation years. But high-mileage cars also typically come with several issues, because their components are reaching the expiry dates.

Before buying a high-mileage car, it’s important to know about the potential issues that might arise with the vehicle.

This article enlightens you about 8 potential problems with high-mileage cars.

Table of Contents

What Is a High Mileage Car?

High mileage vehicles are cars that have been driven more than the average miles. An average American driver drives an average of 10,000-12,000 miles per year. If a car surpasses this figure, it will quickly rack up the miles on the odometer. Any vehicle that has covered 100,000 miles is a high mileage car. It can be a turnoff for some people because those cars don’t have a warranty cover anymore.

Common Problems With High Mileage Cars

Here are some common problems with high mileage cars:

1. Engine Problems

Cars with high mileage and low maintenance often have problems with their engines. High mileage puts a strain on the piston rings that hold the engine’s combustion gases.

This could cause the engine to burn the engine oil too quickly. The first logical step when buying a high-mileage car is to always check the engine oil. Things to look out for include:

• The level of the oil
• The quality of the oil
• The color of the oil

If It has a gritty or dirty appearance, there might be a problem. If it also has a dark color or it smells burned, the engine might be in a bad shape.

2. Failing Transmission

For all cars, when they reach 100,000 miles, their transmission begins to weaken. It is, therefore, crucial to maintain and watch out for signs of a failing transmission. These signs include:

• Difficulty in changing gears
• Burning smell
• Vehicle shaking
• Noises when the car is in neutral
• Slipping gears
• Warning light
• General unresponsiveness

Watch out for these common signs and endeavor to change the transmission fluid every 10,000 miles.

Car experts also discourage the use of high mileage cars for towing because heavy pulling, especially with trailers, directly affects the health of your transmission.

In some severe cases, a slipping transmission cannot be managed and would have to be replaced completely, costing you several thousands.

3. Water Pump Leakage

High mileage cars are susceptible to water pump leaks. In fact, any car that has reached 60,000 to 90,000 miles has a high risk of water leakage. What do the water pump leaks affect?

They affect one major component of the car, which is the cooling system. The water pump circulates the engine coolant that prevents the engine from overheating. The signs to observe when there’s a water pump leakage include:

• Coolant leaks
• Whining noises
• Overheated engine
• Steam
• Rusted areas

Asides from these common signs, ensure to replace your coolant and antifreeze regularly.

4. Failing Timing Belts

A car’s timing belt is the component that aligns the movement of the crankshaft and the camshaft in order to open and close the engine’s valve and allow for smooth combustion.

This apparently shows the crucial need for a good timing belt. A timing belt failure often occurs between 60,000 and 100,000 miles. Luckily, there are several ways to detect a failing timing belt. They include:

• A ticking noise coming from the engine
• Unresponsive ignition (the car may not start)
• Oil leakage around your engine
• Exhaust problems (emits smoke)
• RPM malfunctions

Once you notice these symptoms, urgently replace the timing belts before it completely breaks down and damages your engine. Experts have also recommended that your timing belt should be changed every 100,000 miles.

5. Rusted Areas

This is a general phenomenon in all high-mileage cars. Any car driven past 100,000 miles is likely going to be rusty in some areas. It is worse for areas with frequent downpours (rain or snows) and unfortunately, rust usually spreads to other areas.

You can easily remedy this with repainting, priming, buffing or sanding off the rust. Leaving untreated rust eats away the car’s body, leaving holes in it. When this occurs, only welding can solve the problem, giving you more expenses.

6. Difficult Financing

Most lenders hesitate to cover a car with over a 100,000 miles on the odometer.

It is a reason car owners do not appreciate such vehicles and perhaps if you finally find a deal, you might have to pay for it out of pocket.

7. Lacks Modern Features

Each year automakers up their tech game when manufacturing vehicles. This might include the impressive cruise control, automatic emergency brakes, high beams, heated steering wheels, etc.

Unfortunately, opting for a high-mileage car, specifically early models, might make you miss out on these amazing features.

8. Headlight Issues

High mileage cars often have issues with their headlights. They struggle with seeing properly at night, and this can cause untold hazards for drivers and passengers. However, the dim and unreliable lights come from a weak lens that results from several causative factors. They include:

• The car’s vibrations
• The heat of the car
• Dust and debris
• Solar radiation

The bad part is that some headlights are not compatible with all cars. The connectors simply don’t align, making the replacement impossible. Perhaps you need to replace your headlights. Always check the product to see if it will work with your car’s model.

Should a Car’s Mileage Be a Deal Breaker?

A car with a high mileage should not be written off completely as some of them still make good cars, even with such usage.

The major reason 100,000 miles was used as a yardstick to call out a car as a high mileage vehicle was because when the old classic cars reached a certain limit (99,999 miles) the odometer falls back to zero. Since then, it has been used as a determiner for all cars.

Nonetheless, high mileage cars also have their benefits as against what the majority of people think. They include:

Lesser Price

If you plan to save money while purchasing a vehicle, a high-mileage car might just be the right choice for you. They are usually priced lower than other cars, which definitely means they’re budget friendly.

They Depreciate Slowly

High mileage cars do better than lower mileage cars when it comes to retaining value. So if you plan to just buy and sell after a short period or you are just looking for a durable car, high-mileage cars are better.

They’re Well Maintained

Aside from the established proof of trustworthiness, a well-driven high mileage vehicle will probably perform better than an idle one. If a car has over 100k miles on the odometer and it’s still in great shape, that’s a testament to the excellent maintenance habits of the owner.

General Maintenance of a High Mileage Vehicle

Here are maintenance tips to keep your high-mileage vehicle problem-free:

Change Your Oil Often

We understand this is general knowledge, but there’s no harm in repeating it. Change your engine oil as often as possible.

Car experts recommend changing them at 5,000 miles. If you drive in more demanding terrain or use the car heavily, change the oil more frequently.

Check and Replace Fluids

There are several fluids to always observe before driving the vehicle. They include the co olant, power steering fluid, brake fluid, and windshield wiper fluid.

In addition, also look out for leaks and replace them if there is any.

Replace Filters

Change your air or cabin filter regularly. A dirty air filter can damage your engine while a clogged cabin filter will affect the quality of the air you breathe. Replace them once clogged or old.

Maintain Your Tires

This directly affects your safety. Rotate your tires as often, keep them pumped with the correct air pressure and change as often as you need to. Good tires reduce your chance of having an accident because it puts less strain on the vehicle and extends the health of your car’s suspension.

Care for Your Battery

Without the battery, a car cannot function. With a high-mileage car, you might go through batteries faster, so it’s best to take proper care of them. Some tips include:

• Clean off any corrosion from the battery terminals and the cables.
• Disconnect the cable if you want to wipe off any corrosion..
• Ensure to check the electrolyte level if your battery has a wet cell.