Owner complaints, recalls, fuel economy and safety ratings from public NHTSA and EPA data, updated Oct 17, 2026.
Fuel economy
22–26 mpgcombined; city 19–23, highway 28–32; every version of this model year
Five years of fuel
$15,480–$18,290U.S. average; Ohio $14,580–$17,240 at local prices; every version of this model year; fuel only, not other costs of owning it; 15,000 miles a year, at EIA fuel prices for the week of Oct 12, 2026
NHTSA overall safety rating
Not ratedNHTSA has no overall rating for this year
Owners have filed 3 complaints with NHTSA about the 2014 SLK-Class. These are unverified owner reports, counted by the part of the car they name; one complaint can name several parts. Counts aren't adjusted for how many were sold, so they don't show how reliable a car is.
Complaints by part of the car
Part
Complaints
Crashes
Fires
Injuries
Structure
2
0
0
0
Engine
1
0
0
0
Complaints by model year
Newer years have had less time to collect complaints, and counts aren't adjusted for sales, so a shorter bar doesn't mean a more reliable year.
NHTSA lists 2 recall campaigns for the 2014 SLK-Class over its history. Campaigns are matched by model and year, so each one may apply to a given car, and its repair may already be done: check a VIN on NHTSA's recall lookup for the open recalls on that exact car.
Mercedes-Benz USA, LLC. (MBUSA) is recalling certain 2013-2017 vehicles due to a software fault that may cause the date and time for the emergency call system (eCall) to differ from the actual date and time, potentially relaying an inaccurate vehicle location. For a full list of the affected models visit: https://static.nhtsa.gov/odi/rcl/2019/RMISC-19V787-4620.pdf
Risk: An inaccurate vehicle location may delay emergency responders, increasing the risk of injury.
Remedy: MBUSA has initiated an Over the Air (OTA) remote update. MBUSA will also notify owners, and dealers will check software for a successful OTA or update the communication module software as needed, free of charge. The recall began December 23, 2019. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2019120008.
Mercedes-Benz USA, LLC (Mercedes-Benz) is recalling certain model year 2014 SLK 250, SLK 350, SLK 55 AMG, SL 550, SL 63 AMG, and SL 65 AMG vehicles manufactured March 19, 2014, through May 5, 2014. Due to an air bag assembly error, the front passenger air bag may not deploy properly.
Risk: In the event of a crash necessitating front passenger air bag deployment, the front passenger seat airbag may not properly deploy, increasing the risk of injury to the front passenger seat occupant.
Remedy: Mercedes-Benz will notify owners, and dealers will replace the front passenger air bag, free of charge. Mercedes-Benz distributed an interim letter to owners on July 17, 2014. A second owner letter was mailed after parts became available in mid August 2014. Owners may contact Mercedes-Benz at 1-800-367-6372. Note: Until the vehicle has been remedied, owners are advised that passengers or other items should not be placed in the passenger seat.
Carmakers sent NHTSA 78 service bulletins and notices that cover the 2014 SLK-Class, the latest on Sep 22, 2026. They tell dealers how to fix known issues.
The parts they mention most: electrical system (18), exterior lighting (13), equipment (11), structure (8), engine (6).
NHTSA defect investigations
Opening an investigation isn't a finding of a defect. Outcomes are as NHTSA's summary states them. A recall is shown as an investigation's outcome only where NHTSA's summary names it; other recalls NHTSA's file lists with it are marked as listed, not caused.
Investigation
Part
Opened
Status
Engineering analysis EA21002 Desiccated Air Bag Inflator Rupture · covers 37 makes
The owner's manual gives the oil and how often to change it. We show oil facts only once we've checked them against the manual, and we haven't yet for the 2014 SLK-Class.
EPA class: two seaters. EPA greenhouse gas score: 5–7 out of 10. Each version EPA tested:
Swipe the table sideways for more columns.
Version
Engine
Transmission
Fuel
City / hwy / comb
SLK250 Rear-Wheel Drive
1.8 L, 4 cyl, turbo
Automatic 7-spd
Premium Gasoline
23 / 32 / 26
SLK250 Rear-Wheel Drive
1.8 L, 4 cyl, turbo
Manual 6-spd
Premium Gasoline
22 / 32 / 26
SLK350 Rear-Wheel Drive
3.5 L, 6 cyl
Automatic 7-spd
Premium Gasoline
21 / 28 / 24
SLK55 AMG Rear-Wheel Drive
5.5 L, 8 cyl
Automatic 7-spd
Premium Gasoline
19 / 28 / 22
Sources and dates
U.S. EPA fuel economy data, file of Sep 29, 2026
NHTSA owner complaints, file of Oct 17, 2026
NHTSA recalls, file of Oct 17, 2026
NHTSA manufacturer communications, file of Oct 17, 2026
NHTSA defect investigations, file of Oct 17, 2026
NHTSA 5-Star Safety Ratings, file of Aug 7, 2026
U.S. Energy Information Administration, file of Oct 12, 2026
Fuel cost: EPA mpg with fuel prices for the week of Oct 12, 2026 and electricity prices for Jul 2026. Source: U.S. Energy Information Administration (Oct 2026). Complaints are unverified reports owners filed with NHTSA. About the data