If You Put the Wrong Fuel in Your Tank, Will Insurance Pay for Damages?

Last Updated on October 18, 2026

By James Shaffer Reviewed by Thomas Rockford, insurance industry executive and financial analyst, on October 18, 2026 How we fact-check

Putting the wrong fuel in your tank (often called misfueling) is one of those mistakes that can happen fast—especially on road trips, when you’re exhausted, or when you switch between gas and diesel vehicles. The good news: if you catch it early, it’s often a “tow + drain + refill” problem. The bad news: if you start the car (or drive), repairs can get expensive.

If you’re dealing with misfueling right now, your first question is probably whether insurance will pay for the damages. In most cases, standard auto insurance won’t—but there are a few exceptions and workarounds that can help.

Most standard auto insurance policies don’t cover wrong-fuel damage because it’s usually treated as driver error leading to mechanical damage.
If you catch the mistake before starting the engine, the fix is often limited to towing (if needed) plus draining/flush and refilling with the correct fuel.
Gasoline in a diesel vehicle is typically the most expensive scenario—shut the engine off immediately and tow it to a shop.
You might get help through roadside assistance (towing) or a mechanical breakdown plan, but misfueling is commonly excluded—always check your policy terms first.

Table Of Contents

First steps: what to do immediately after misfueling
What happens when you put the wrong fuel in your tank?
How much does it cost to fix a wrong-fuel mistake?
Will auto insurance pay for wrong-fuel damage?
Will my car warranty cover misfueling?
How to prevent accidental misfueling
FAQs on Putting the Wrong Fuel in Your Car
Sources

First steps: what to do immediately after misfueling

What you do in the first 60 seconds matters more than the type of fuel you used.

Don’t start the engine. If you notice the mistake at the pump, stop right there. Starting the car circulates the wrong fuel through the fuel system and can turn a simple drain into major repairs.
If you already started it, shut it off ASAP. Don’t “try to make it home.”
Move the car only if you can do it safely without running the engine. If you’re blocking a pump, ask for help pushing it to a safe spot.
Call for a tow or mobile fuel-drain service. Many roadside plans can help with towing even if they don’t pay for the drain itself.
Save receipts and document what happened. If there’s any chance you’ll pursue reimbursement (or you were sold contaminated fuel), documentation helps.

What happens when you put the wrong fuel in your tank?

Misfueling damage depends on what you put in, what the vehicle requires, and whether the engine was started. Here are the most common scenarios.

Diesel in a gas car

Diesel doesn’t ignite the same way gasoline does, so many gas engines will run poorly (or stall) once diesel reaches the combustion side. If the car wasn’t started, a drain and refill may be all you need. If you drove, diesel can foul components and create bigger headaches. If you keep driving, you can end up with serious mechanical problems—including a situation that looks like your engine is failing.

Gasoline in a diesel vehicle

This is usually the more expensive mistake. Diesel fuel lubricates parts of the fuel system that gasoline does not. In many modern diesel engines (especially common-rail systems), gasoline contamination can damage fuel pumps and injectors quickly. You may notice knocking, loss of power, or a misfire-like symptom—then the vehicle may shut down entirely. If you put gas in a diesel, don’t drive it. Shut it off and tow it.

DEF in the fuel tank (diesel exhaust fluid)

DEF is not fuel. If DEF ends up in the diesel tank, it can contaminate the system and lead to costly repairs—especially if the engine is started. Treat it like gasoline-in-diesel: don’t drive, and get professional help right away.

Wrong octane or the wrong ethanol blend

Not all “wrong fuel” situations are catastrophic:

Premium vs. regular: If your car recommends (but doesn’t require) premium, a tank of regular usually won’t cause damage—though you may notice reduced performance. If premium is required, consistent use of lower octane can contribute to engine knocking and long-term wear.
E85 vs. regular gas: The Department of Energy defines E85 as a blend of 51% to 83% ethanol, and says flex fuel vehicles differ from gasoline-only cars in having an ethanol-compatible fuel system and a different powertrain calibration. If your vehicle isn’t a flex fuel model (check the fuel door and the owner’s manual), E85 can cause drivability issues and possible damage over time. If you accidentally put E85 in a non-flex-fuel vehicle, stop driving and call a shop for guidance.

How much does it cost to fix a wrong-fuel mistake?

Costs vary by vehicle and how quickly you catch the mistake, and no insurer or repair data publisher we could rely on prints a standard price for this job, so ask the shop for a written estimate. What you are paying for changes at each stage:

Catch it before starting: A tow if the car can’t be pushed clear, the labor to drain the tank and flush the lines, and a fresh tank of the right fuel. This is the cheapest version of the mistake.
Started the car but shut it off quickly: The same drain and flush, often plus a fuel filter and more labor, depending on how far the wrong fuel traveled through the system.
Drove it (especially gas in a diesel): The high-pressure fuel pump and injectors may need replacing, and on a modern diesel those are among the most expensive parts in the fuel system. Get the diagnosis in writing before you approve the work.

The takeaway: the cheapest misfueling fix is the one where you don’t start the engine.

Will auto insurance pay for wrong-fuel damage?

Usually, no. The California Department of Insurance’s consumer guide (revised February 5, 2025) puts it plainly: collision covers damage to your car caused by physical contact with another vehicle or an object, comprehensive covers damage caused by something other than a collision, and comprehensive “does not cover mechanical breakdown, normal wear and tear, or maintenance.” Misfueling is neither a collision nor an outside event like theft or hail, so most policies treat it as driver error leading to mechanical damage and exclude it. Your own policy’s exclusions section is the final word.

When you might have some coverage

Roadside assistance: Even if insurance won’t pay for the fuel-system work, a roadside plan may cover towing to a repair shop.
Mechanical breakdown coverage: If you have mechanical breakdown coverage, misfueling might be covered—but many plans exclude it. Read your contract carefully before filing.
Contaminated or wrong fuel sold by a station: If the station’s fuel was contaminated or mislabeled, your best path may be seeking reimbursement from the station (or their insurer). Keep receipts, take photos, and get a written diagnosis from the shop.

If you’re thinking about filing an insurance claim anyway, weigh whether it’s worth it. A small claim may be denied—and even approved claims can sometimes affect future premiums. This same “is it worth claiming?” logic applies outside accidents too: consider the trade-offs before you file.

If your insurer tells you misfueling is covered under a specific endorsement or add-on, follow the proper way to file an insurance claim so your documentation is clean and your timeline is clear.

Will my car warranty cover misfueling?

Typically, no. The FTC describes a manufacturer’s warranty as a contract to fix certain defects or malfunctions for a set time after you buy the car, and notes a claim can be denied if it appears you didn’t maintain the vehicle. Damage caused by the wrong fuel or contamination is not a defect in the car. If you just bought a new car, don’t assume “it’s under warranty” will protect you here. Misfueling is commonly treated as preventable damage.

How to prevent accidental misfueling

Most wrong-fuel mistakes happen when you’re distracted or switching between vehicles. These quick habits lower the odds:

Check the fuel door label every time—especially in a rental, work vehicle, or diesel truck you don’t drive daily.
Slow down at unfamiliar stations. Labels, nozzle colors, and pump layouts vary.
Don’t “top off” while multitasking. Finish the fueling first, then check your phone, snacks, or GPS.
If you drive both gas and diesel vehicles, consider a visual reminder (a tag on the keychain or a note on the dash).

If misfueling does happen, the best damage-control move is simple: turn the car off immediately and get professional help before the wrong fuel circulates through the system.

My advice is to call your roadside plan before you call your insurer, since a tow is the one thing most policies will actually pay for here, and to ask the shop to write “misfueling” on the estimate with the parts listed. If the station’s pump was mislabeled, that written diagnosis plus your receipt is what gets the station’s insurer to pay instead of you.

FAQs on Putting the Wrong Fuel in Your Car

Will car insurance cover damage from putting the wrong fuel in my tank?

Usually not. Most standard auto policies are designed for crash-related or external damage (like theft or weather), not mechanical damage caused by misfueling. You may still have towing help through roadside assistance, and some specialty endorsements or add-ons may apply—so it’s worth checking your specific policy language.

Does comprehensive insurance cover misfueling?

In most cases, no. California’s Department of Insurance consumer guide says comprehensive does not cover mechanical breakdown, normal wear and tear or maintenance, and misfueling is treated as driver error that leads to mechanical damage, which is commonly excluded. If an insurer does cover it, it’s usually through a specific endorsement, add-on coverage, or a specialty contract rather than ‘standard comprehensive’ alone.

What should I do if I realize I put diesel in a gas car (or gas in a diesel)?

Don’t start the engine. If you already started it, shut it off immediately. Then arrange towing or a mobile service to drain the tank and flush the system. The fastest way to turn a manageable repair into a major one is to keep driving after the mistake.

How much does it usually cost to drain the tank after misfueling?

There is no standard price, and it depends on your vehicle and the shop. If you catch it before driving, you are paying for a tow if needed, the labor to drain and flush the system, and a tank of the right fuel. If you drive with the wrong fuel, especially gasoline in a modern diesel, the high-pressure pump and injectors may need replacing, which is where the bill climbs. Ask for a written estimate before approving work.

What if the gas station sold contaminated or incorrect fuel?

That’s different from accidentally choosing the wrong pump. If the station’s fuel was contaminated or mislabeled, you may be able to seek reimbursement from the station (or their insurer). Save your receipt, take photos of the pump/signage, and ask the repair shop for a written diagnosis describing the contamination and resulting damage.

Will mechanical breakdown insurance (MBI) cover wrong-fuel damage?

Sometimes, but many MBI plans exclude misfueling. Mechanical breakdown coverage varies widely by insurer and contract, and eligibility rules also vary by vehicle age and mileage. Before filing, read your policy’s exclusions and call your provider to confirm whether misfueling is covered.

Will my manufacturer warranty cover damage from the wrong fuel?

Typically no. Warranties usually cover defects in materials or workmanship—not damage from using the wrong fuel or contamination. If you’re unsure, review your warranty booklet and ask the service department, but don’t count on warranty coverage for misfueling repairs.

Sources

Checked October 18, 2026