We get it: You’re busy. And taking your car in for maintenance or repairs isn’t fun. For some people, it’s right up there with going to the dentist. You’re definitely not alone if you’ve neglected things like changing your oil or replacing your tires — as we discovered in our survey of 1,200 American car owners.

But letting car maintenance slide is a risky proposition. Days can turn into weeks or even months, potentially jeopardizing your safety, shortening the life span of your car, and leading to much more serious and costly repairs.

We reached out to drivers across the country to understand which tasks people are most likely to put off, how long they delay, and why. We also tallied the potential costs of skipping routine maintenance. Read on to see what we learned:

• The 10 Most Delayed Car Maintenance Tasks
• 6 Reasons People Avoid the Mechanic
• The High Cost of Delayed Car Maintenance
• #1 The most-ignored car problem? Cracked windshields
• #2 Out of line: Driving with wheels needing alignment
• #3 Dirty Driving: Not getting regular oil changes
• #4 Tire tread: Letting car tires get bald or worn out
• #5 It’s probably nothing: Ignoring the “check engine light”
• #6 Can’t stop, won’t stop: Responding slowly to sluggish brakes
• #7 Squeaks, rattles, and groans: Ignoring unusual car noises
• #8 Going, going, going flat: Driving with a slow leak in a tire
• #9 Murky motoring: Running out of windshield washer fluid
• #10 Paddidle! Driving with a burned-out headlight
• Conclusion
• Methodology

People gave us a variety of reasons why they let things slide.

The biggest factors were being too busy (54.3%), being unable to afford it (52.2%), thinking the problem was not urgent (34%), the length of time the repair might take (29.3%), anxiety around car-related issues (17.8%), and distrust of mechanics (13.4%).

Interestingly, anxiety and distrust of mechanics were slightly more of an issue for men than women:

• 18.4% of men said they delay car maintenance because of anxiety around automotive matters, compared with 16.9% of women.
• 14.3% of men said they distrust mechanics, compared with 11.8% of women.

Also, younger people feel more anxiety and distrust around automotive tasks than older people.

• 23.8% of people in their 20s said they have delayed repairs because of anxiety, compared with 8.9% of people in their 60s.
• 15.4% of car owners in their 20s said they distrust mechanics, compared with 12.7% of people in their 60s.

A 37-year-old man from Florida said:

A 50-year-old woman from Oregon told us a second opinion recently saved her from a big bill.

Our survey found that windshield cracks were by far the most neglected car maintenance issue, with 26.7% of drivers admitting having ignored one for more than three months.

Why ignoring a cracked windshield is bad

Cracked windshields may not seem like a big deal, but the chips and spidery fractures caused by road debris are more than a cosmetic problem. As they spread, they can limit visibility and weaken the structural integrity of your car, putting you at much greater risk of injury during a collision or rollover accident.

How much it can cost

Many insurance policies cover glass repairs or replacement with no deductible, but if yours doesn’t, here’s what you can expect: If you catch a crack or chip early, it might be suitable for repair. Chips smaller than a quarter and cracks shorter than a dollar bill can often be patched. Generally, the smaller the blemish is, the cheaper it is to repair. Without insurance, glass repair typically runs between $60 and $125.

Windshield replacement costs vary by location, make and model of the vehicle, and the type of glass used. In one study of average repair costs in 16 U.S. cities, a replacement windshield for a Honda Accord cost $250 to $300, while one for a BMW X6 ranged from $350 to $450.

If you don’t replace your windshield and get into an accident:

• In a front-end collision, cars are designed to absorb impact with crumple zones. As the force moves to the passenger compartment, the curve of the windshield is supposed to reinforce the frame, enable the airbags to function properly, and prevent the windshield from collapsing in on the passengers and the A-pillars from folding inward.
• In a rollover accident, the strength of the windshield helps to absorb some of the impact and prevent catastrophic roof collapse as well as the injuries that could ensue.
• If poor visibility via defective windshield was a factor in the accident, you could be found negligent and liable for damages.

Engine oil is arguably the second-most important fluid in your car after fuel. It helps keep your engine running smoothly and prevents overheating. Most vehicles need oil changes every 3,000 to 6,000 miles.

In most cases, an oil change takes less than an hour, but many people still postpone doing it.

Modern cars usually have a dashboard light that comes on when you’re due for new oil. You also might have a sticker on your windshield with the date and mileage of your last change. Despite those cues, many people delay doing this mundane task.

The biggest group of car owners (38.3%) reported waiting 7 to 30 days past the recommended time to change their oil. Almost a third (31%) delayed by more than a month.

Why postponing oil changes is bad

Over time, oil can become thick and sticky. The engine has to work harder, leading to reduced fuel efficiency, sluggish acceleration, and a rough idle. Tiny particles build up and can act as abrasives, wearing down engine parts like crankshaft bearings, camshafts, and gaskets.

You might notice oil leaks and engine smoke from overheating. In the worst case, you can have a total engine seizure or failure.

How much it can cost

Oil changes typically cost between $35 and $75 for conventional oil and $65 to $125 for synthetic oil. The type of oil you need will depend on your vehicle model.

If you go more than 8,000 miles without changing the oil, you could end up also having to replace worn parts — possibly the valve cover gaskets (about $225), intake manifold gaskets (about $300), head gaskets ($1,290-1,560), camshafts (about $1,300-1,500), and crankshafts (average $1,642), among others.

If you still don’t act, eventually thick, dirty oil can result in catastrophic engine failure. Replacing the entire engine can cost $4,000 to $7,000 or more, plus $1,100 to $1,800 for labor — more than you’d likely have spent on routine oil changes over the life span of your vehicle.

A 31-year-old woman from Colorado told us neglecting oil changes was one of her “most expensive mistakes ever.” She said

For some car owners, dismissing the “check engine” light is akin to hitting the snooze button. It’s a feature of the dashboard that, once ignored, becomes easy to tune out.

A full 15% of U.S. drivers admit disregarding a dashboard warning for more than 3 months. There are a lot of reasons why that’s a bad idea.

Why ignoring the “check engine” light is bad

Your car’s check engine light is its only way to communicate that something isn’t working as it should. Unfortunately, it doesn’t usually give you a lot of information.

The problem might be as minor as a loose gas cap, but it could also be a critical system like the fuel injection, ignition, or emission controls. Many problems worsen over time..

How much it can cost

There are myriad things that can trigger a check engine signal. One common problem that accounts for up to 10% of all check engine messages is a faulty oxygen sensor. Replacing an oxygen sensor right away costs about $350.

Ignoring that repair can decrease your gas mileage by 40%, cause power loss, and ruin your catalytic converter, which costs about $1,700 to replace.

Cars are supposed to purr — not grind, wheeze, or squeal. But spend a few minutes at a busy intersection and you’re sure to hear the sounds of vehicles in distress.

Most people take it seriously when their vehicle starts making weird or alarming noises, with 41.5% getting it into a mechanic within three days. But not everyone is as diligent. Nearly a quarter of car owners (24.4%) have ignored car noises for a month or longer.

Why ignoring car noises is bad

Different noises can signal different issues. Squealing noises are usually brake-related. (Brake pads have a built-in wear indicator that’s designed to make a high-pitched noise when it comes in contact with the brake rotor.)

Ticking sounds from the engine often mean the timing belt is starting to fail. Clunking or banging under the hood might be valves, connecting rods, or pistons.

Popping or clicking sounds when you turn could be the CV joints on your front axle. Howling or singing noises might indicate a fluid leak or bad wheel bearings.

Most problems that involve noises get worse over time. As expensive as a timely repair might be, it’s a safe bet that procrastinating will raise the price tag as well as the safety risk.

How much it can cost

Many things could be wrong when your car starts making weird noises, but one common scenario is a bad timing belt. The timing belt is a rubber and nylon component that connects the engine’s camshaft and crankshaft, keeps them in sync, and makes sure each cylinder fires at the appropriate time.

Timing belts are often replaced as part of scheduled maintenance every 80,000 to 100,000 miles. Having a timing belt replaced before it breaks typically costs between $576 and $659.

Waiting for your timing belt to snap before replacing it raises the cost by a lot. When the belt breaks, the valves and pistons no longer run in sync and collide with each other. This can bend the valve stems, gouge the pistons, crack the connecting rods, and damage the engine’s cylinder walls.

In a worst-case scenario, if the timing belt breaks at high speed it can crack the engine block, requiring a complete engine replacement.

Windshield wipers are the solution to smeared and grimy windshield glass, but only if there’s fluid in the reservoir tank.

Why driving without windshield washer fluid is bad

Mud, pollen, bugs, rain, and snow can all obscure a driver’s view — and the worse your visibility is, the greater your risk of getting into an accident. Low visibility conditions are blamed for 38,700 vehicle crashes, 16,300 injuries, and 600 deaths each year, according to the U.S. Department of Transportation.

How much it can cost

Topping up the windshield fluid is a courtesy service at most garages. But if you want to do it yourself, you can pick up a gallon of basic windshield washer fluid at almost any big-box store, gas station, or grocery store for about $2-3. (Deluxe formulas with additives to repel rain or remove bug residue may run closer to $15.) Then just open the hood and look for a reservoir on the right or the left. It should be easy to spot; it will have a plastic cap with a windshield symbol on it.

A few dollars for windshield fluid is a small price to pay, especially considering the risk of an accident if you can’t clear an obstruction from your view.

When time and money are both tight, it can be tempting to let car maintenance slide — especially if your vehicle is still operable and driving reasonably well. But delaying seemingly small car care tasks can turn little problems into big, expensive ones. In the worst-case scenario, ignoring car repairs can have deadly consequences.

There are many affordable ways to prevent the sticker shock of a major repair. Windshields and tires can often be patched, if you catch the problem early enough. You can refill windshield washer fluid yourself for a few dollars, rather than risk being blinded by a mud splatter. Checking reviews is a good way to find a reputable mechanic who won’t overcharge or upsell you. And buying quality used tires can be a safe, affordable alternative to paying full price for new ones.

Our study was conducted online. We surveyed 1,207 U.S. residents who have owned a vehicle for at least two years and are primarily responsible for the vehicle’s maintenance. Respondents were 57.7% male and 41.7% female. Seven people (.6%) identified as non-binary.

Participants ranged in age from 18 to 76, with a median age of 37. They came from 48 states (all but Alaska and Vermont) with a distribution as follows: South, 447 (37.5%); West, 279 (23.4%); Midwest, 240 (20%); Northeast, 229 (19.1%) – based on U.S. Census-defined regions.

The median household income was $50,000 to $75,000 with 39.5% earning less and 35.4% earning more.

The survey was based on self-reporting, which can have limitations. However, the margin of error was ±2.82% with a confidence interval of 95% based on the estimated population of 237.3 million car owners in the U.S.

Price estimates came from several aggregator websites including RepairPal, AAA, Kelley Blue Book, Edmunds, and AutoServicesCosts.com. The estimates use the MSRP (manufacturer’s suggested retail price) for parts and automotive industry standard labor times and rates. Costs were generally presented as ranges, since many variables can influence actual price, including the make, model, year, condition, and location of the vehicle.

For the “procrastination price tag” figure, we used the midpoint of the cost difference between prompt and delayed action. For the average total cost of delayed maintenance, we accounted for the probability of each consequence actually happening by multiplying the “procrastination price tag” by the percent of respondents who ignored each issue for more than 90 days.

If you are a journalist or blogger interested in covering this project, there’s no need to delay using our research. You’re welcome to reproduce any of the findings or images in this article for noncommercial use. All we ask is that you give proper credit by linking back to this page.