Fuel leak or fuel odor on the 2011 Mercedes Benz C300
When fuel leak or fuel odor gets reported
Owners of the 2011 Mercedes Benz C300 report fuel leak or fuel odor at a median of 75,000 miles. A quarter of the reports come in before 60,000 miles and a quarter after 90,000 miles, from 12 reports that carried an odometer reading.
A part like this is normally expected to survive 90,000 miles. It is the 4th most-reported problem on this model year.
The mileage distribution
The reported range runs from 5,000 miles at the tenth percentile to 125,000 miles at the ninetieth, a spread of 119,265 miles across the middle 80% of reports.
A spread this wide points at use rather than design. Towing, climate, service history and city mileage all move a failure like this, so the median is a weak guide to any individual car.
17% of the dated reports were filed under 36,000 miles.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| 5,235 miles | 60,750 miles | 76,000 miles | 90,750 miles | 124,500 miles |
Read the 10th percentile as “one report in ten arrived this early”. Exact figures are shown in this table because it is the table of record; everywhere else on the site they are rounded to the precision the sample can carry.
What a percentile can and cannot tell you here
These five numbers describe the readings owners gave, in order. The median is the middle one: half the reports arrived below it. The 10th and 90th are the edges of the bulk of the distribution, and the distance between them is the part worth reading. A tight spread — say 70,000 to 95,000 miles — points at something that wears out on a schedule, and the schedule is knowable. A wide one, 20,000 to 190,000, points at a fault that hits some cars and never troubles others, which means the mileage on the listing in front of you tells you very little about your odds.
What these figures are not is a survival curve. Every reading here comes from a car whose owner filed a complaint, so the sample contains only failures: it cannot say what share of the fleet made it past 150,000 miles untouched, because those owners had nothing to report. Nor is the mileage the moment of failure — it is the odometer reading as recalled at the time of filing, which may be weeks later and is sometimes rounded to the nearest ten thousand by the person typing it.
Percentiles are shown at all only once 8 readings exist for the vehicle and mode. Below that the middle of a handful of numbers is noise wearing a decimal point, so the figures are withheld rather than dressed up.
What happens, and what it costs
Putting it right typically runs $300–$2,500 at an independent US shop. That range is an editorial estimate held in this site's failure-mode catalogue, not a figure from NHTSA, and it is a repair cost rather than a diagnosis cost.
This mode is classified as critical, which means a failure can leave the car unable to stop, steer, or stay out of the way of traffic. It is weighted accordingly in the risk score.
The same failure on other years
The same failure is reported on 5 model years of this car. It shows up earliest on the 2015, at a median of 50,000 miles, and latest on the 2009 at 120,000 miles.
By volume the 2011 is the worst of them, which makes this a problem of this specific year rather than of the model as a whole.
If one year stands out to the left, that is the year to avoid; if the whole line sits at a similar mileage, this is wear rather than a defect in one production run.
Tick median reported mileage Solid middle half of reports Faint 10th to 90th percentile Colour how bad the failure is when it happens
What owners wrote
Verbatim from NHTSA complaint narratives, trimmed for length. The mileage is the one the owner gave.
I filled my gas tank up friday evening, went home and parked my vehicle in the garage. The next morning there was a strong smell of gasoline coming from the car. I took it to the mercedes dealer and they said the seal and cap under the passenger back seat needed to be replaced. They wanted to charge $434. Not only is this dangerous it should not be the consumers responsibility when the manufacturer provided faulty material.
I was driving and a strong fuel odor was experienced. When I stopped the car and looked under the undercarriage there was a puddle of fuel. There is a fuel leak coming from the bottom plastic underneath the gas tank. It may be the fuel filter as the same year and model had a recall but apparently my vehicle was not covered. *tr
I had to pay for a fuel filter leak due to a crack of the fuel filter flange and was told this was not a recall on my vehicle, but when I was looking at recalls for my year and model I came across NHTSA campaign number-12v557000 with a recall on merceded-benz c300 4 matic model year 2011-2012 for fuel leak due to cracked flange. I asked the dealership about it even though that is exactly what had to be replaced and said it did not affect my vehicle, I called mercedes benz at the number provided in the remedy section of the announcement and was told it was not my vehicle, please advise what I should do next, thank you
Also reported on the 2011 Mercedes Benz C300
Airbag inflator rupture
Control arm, ball joint or bushing failure
No-start or intermittent start failure
Other electrical problem
Fuel tank, filler or EVAP failure
Other steering problem
How far this goes
Complaints are voluntary, so 21 is a floor and not a count of affected cars. Mileages are typed in by owners and cluster on round numbers. And the mode itself is assigned by software reading the complaint text, which is reliable in bulk and fallible one report at a time.
Questions this page answers
At what mileage does fuel leak or fuel odor happen on the 2011 Mercedes Benz C300?
Across 12 owner reports that included an odometer reading, half were filed by 75,000 miles. A quarter were filed before 60,000 miles and a quarter after 90,000 miles. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is fuel leak or fuel odor on the 2011 Mercedes Benz C300?
21 reports have been filed with NHTSA, about 2.0 per 1,000 vehicles. Complaints are voluntary, so this is a floor rather than a count of affected cars.
What this is and is not. These are the mileages at which owners chose to complain to a federal agency, which is not the same as the mileage at which the part fails on every car. It skews toward failures that happened outside warranty, cost real money, or frightened someone. It is still the only public dataset that carries failure mileage at all, and the shape of a few hundred readings is informative even when a single one is not. Methodology · JSON · this failure on other cars
Source Owner complaints and recall records published by the US National Highway Traffic Safety Administration, model years 1996–2027 Figures rebuilt Published by AtWhatMileage How every figure is computed