The 2018 Mercedes Benz S Class has no open NHTSA recalls. Owners report 6 recurring issue clusters, led by “Steering malfunction warning and unresolved recall.” Mercedes-Benz alternates two service events: Service A (oil, filter, inspection) at roughly 10,000 miles or 1 year, then Service B (Service A plus brake fluid, cabin filter, and deeper checks) at roughly 20,000 miles or 2 years — the ASSYST Plus counter in the cluster tells you which is due. Oil must carry the MB-Approval number your engine specifies (commonly 229.5, or 229.71 for newer 0W-20 engines); 'meets or exceeds' marketing language is not an approval. Electric EQB and EQS models keep the A/B rhythm for inspections, brake fluid, and cabin filters — just without oil.
No open recalls on file. NHTSA lists no unrepaired safety recalls for this year, make and model. A recall can be issued at any time, and a specific car can still have one open — check yours by VIN at nhtsa.gov/recalls.
What drivers and federal regulators have officially reported about the 2018 Mercedes Benz S Class.
STEERING
3 NHTSA complaints · 2019-04 → 2023-05
“Steering wheel became extremely stiff to turn and a message that read “steering malfunction increase physical effort” appeared while driving at around 30 mph while in a vacation trip, not only was this extremely unsettling since it happened suddenly but I had”
“2018 MERCEDES BENZ S CLASS. CONSUMER WRITES IN REGARDS TO NHTSA RECALL 18V-910. *LD *JS”
ENGINE
5 NHTSA complaints · 2021-10 → 2025-06
“The engine failed while my friend was driving. The car is available for inspection. My friend almost got into a car accident because the car started shaking and the steering wheel closed up before the engine completely failed. Additionally, the airbags did”
“Walk Home Condition -I purchased a 2018 CPO Mercedes-Benz S560 on 8/20/21 from Knauz Continental Autos in Lake Bluff, IL. On 9/25/2, at approx noon, I was driving the vehicle and the engine light came on, the throttle/engine felt sluggish and not responsive”
FUEL/PROPULSION SYSTEM
2 NHTSA complaints · 2021-03 → 2022-10
“The Smell of fuel is present inside the vehicle around 50 percent of the time. When parked in the garage the vehicle emits an extremely strong fuel smell as if it has leaked fuel with no visible spills or leaks. While driving the smell of fuel is present”
“WHEN THE CAR IS LIFTED IN THE FRONT (TO CHANGE BOTH TIRES) THERE IS A STRONG ODOR OF FUEL COMING FROM THE REAR OF THE CAR WHEN WALKING AROUND THE BACK. THE TANK WAS 50%FULL AND THIS OCCURS WHENEVER THE CAR IS LIFTED IN THE FRONT”
ELECTRICAL SYSTEM, COMMUNICATION
2 NHTSA complaints · 2021-06 → 2021-07
“The contact owns a 2018 Mercedes-Benz S560. The contact received notification of NHTSA Campaign Number: 21V058000 (Communication, Electrical System) however, the part to do the recall repair was unavailable. The contact took the vehicle to the local dealer”
“Recall # 21V058 The above Safety recall has not been cleared via dealer. (Two visits). I mentioned to dealer and they claim that it gets resolved "over the air". If so, then why hasn't it been resolved”
SERVICE BRAKES
2 NHTSA complaints · 2020-08 → 2023-03
“BRAKES FAILED WITH NO PRIOR WARNING WHILE DRIVING AT RATED SPEED LIMIT OF 55 MPH AND TRYING TO SLOW DOWN THE CAR TO MAKE A RIGHT TURN. NO BRAKE RESPONSE AND BARELY MISSED WRAPPING THE CAR TO THE POWER LINE LOCATED ON ROUTE 62 AND BATEMAN ROAD IN BARRINGTON IL”
“The contact owns a 2018 Mercedes-Benz S450. The contact stated while driving at an undisclosed speed, the contact attempted to depress the brake; however, the vehicle failed to decelerate and slow as needed. The contact stated that the brakes failed to work”
FORWARD COLLISION AVOIDANCE
3 NHTSA complaints · 2017-12 → 2023-12
“TL* THE CONTACT OWNS A 2018 MERCEDES-BENZ S450. WHILE DRIVING 75 MPH WITH THE CRUISE CONTROL ENGAGED, THE AUTOMATIC BRAKING ACTIVATED ON ITS OWN IN TRAFFIC. THE CONTACT HAD TO DEPRESS THE BRAKE PEDAL TO DISENGAGE THE CRUISE CONTROL IN ORDER TO DRIVE SAFELY”
“THE PRE-COLLISION SAFETY FEATURE GOES OFF WHEN THERE IS NO COLLISION IMMINENT. IT IS FRIGHTENING AND COULD ACTUALLY CAUSE AN ACCIDENT”
Issues on other model years
Source: NHTSA Office of Defects Investigation (ODI). Complaint data refreshed Sep 17, 2026. Investigation data refreshed Sep 17, 2026.
We display NHTSA's record with attribution; we don't editorialize on what these complaints mean for any specific vehicle.
Critical for safety and preventing major damage
Every 10,000 miles or 12 months: oil and filter with MB-Approved oil, fluid top-offs, tire check, and inspection. AMG models driven hard: many owners service at 5,000-7,500 miles.
Estimated cost — typical U.S. ranges
Dealer
~$120–$160
Shop
~$85–$115
DIY
~$25–$55
Full synthetic costs more than conventional. 5-quart 0W-20 + filter is the typical bill.
Every 20,000 miles or 2 years, alternating with Service A: everything in A plus brake-fluid replacement, cabin filter, and a deeper multi-point inspection of brakes, suspension, and driveline.
Estimated cost — typical U.S. ranges
Dealer
~$85
Shop
~$60
DIY
Free
Most shops do this free with any paid service. A flashlight and 10 minutes covers the basics yourself.
Rotate at every Service A where the tire sizes allow. Many AMG and 4MATIC+ models run staggered widths that can't rotate front-to-rear — check your spec before paying for a rotation.
Estimated cost — typical U.S. ranges
Dealer
~$85
Shop
~$60
DIY
Free
Often free at the shop where you bought the tires — worth asking before paying.
Checked at every A/B service via electronic pad-wear sensors. Replace sensors with pads. Heavy EQS models wear pads slowly (regen braking) but rotors can corrode from disuse — an inspection catches that.
Estimated cost — typical U.S. ranges
Dealer
~$85
Shop
~$60
DIY
Free
Most shops do this free as a courtesy with any service. Don't pay separately if you can avoid it.
Replaced every 2 years as part of Service B — Mercedes schedules it on time, not miles, because DOT 4 fluid absorbs moisture regardless of driving.
Estimated cost — typical U.S. ranges
Dealer
~$180–$200
Shop
~$125–$140
DIY
~$10–$25
DOT 3 or 4 — match the cap. Vacuum bleeders make this a one-person DIY.
Keeps your vehicle running smoothly and efficiently
Mercedes specifies fluid and filter service around 70,000 miles on most 7G- and 9G-Tronic gearboxes — check your year's sheet. Use only the MB-spec fluid for your transmission code; independent specialists often service at 60,000 on hard-driven cars.
Estimated cost — typical U.S. ranges
Dealer
~$330–$500
Shop
~$235–$355
DIY
~$60–$180
Some sealed transmissions have no dipstick — fill is precise and best left to a shop. Many drivers can still DIY drain-and-fill.
Most modern MB gas engines: plugs around 60,000 miles — AMG engines often sooner. Check your engine's sheet; twin-turbo V8 plug jobs are labor-heavy, so pair with other scheduled work.
Estimated cost — typical U.S. ranges
Dealer
~$285–$390
Shop
~$200–$275
DIY
~$25–$100
Iridium plugs cost more but last 100k+ miles. V6/V8 access varies wildly — some are tough.
Replace around every 40,000 miles (twin-filter setups on V6/V8 engines double the parts bill). Inspected at every Service B.
Estimated cost — typical U.S. ranges
Dealer
~$60–$95
Shop
~$45–$70
DIY
~$15–$40
5-minute job on most cars; the airbox lid usually has clips, no tools needed.
Extends the life of your vehicle and improves comfort
Replaced with every Service B. Models with the ENERGIZING air package use a higher-grade filter — priced accordingly.
Estimated cost — typical U.S. ranges
Dealer
~$60–$95
Shop
~$45–$70
DIY
~$15–$40
Usually behind the glovebox. Shops charge labor for a 10-minute job — easy DIY win.
MB-spec coolant is long-life (typically ~10 years / 150,000 miles on the sheet). Refresh only with MB 325/326-spec coolant — the wrong chemistry attacks aluminum and head gaskets.
Estimated cost — typical U.S. ranges
Dealer
~$285–$330
Shop
~$200–$235
DIY
~$25–$60
Use the manufacturer-specified coolant — wrong color/chemistry can damage the cooling system.
Test annually after year 3. Most modern Mercedes carry a second auxiliary battery; a weak one triggers cascading warning messages long before a no-start. EQ models also depend on the 12V system to boot.
Estimated cost — typical U.S. ranges
Dealer
~$225–$390
Shop
~$160–$280
DIY
~$130–$250
Most auto-parts stores test and install batteries free with purchase. Skip the dealer markup.
Occupant deaths in fatal crashes (FARS)
5 crashes 2010–2024
FARS counts every occupant death in a fatal crash, whatever the cause — it does not mean the vehicle was at fault or defective. Counts are not adjusted for how many of each vehicle are on the road. How to read this number
Owner-reported problem signals
Separate from the federal fatality data above: complaints owners filed with NHTSA about this year and model. These are reports of problems, unverified, and are counted here only as signals.
2
complaints mentioning a crash
2
complaints mentioning a fire
Typical U.S. ranges. Actual quotes vary by shop, parts choice, and vehicle condition.
How we estimate: Dealer = OEM parts × 1.4 + labor × $165/hr. Shop = parts + labor × $115/hr. DIY = parts only.
This maintenance schedule for the 2018 Mercedes Benz S Class reflects Mercedes-Benz's published service intervals and the ASSYST Plus (Service A / Service B) system. Your actual service needs may vary based on driving conditions, climate, and vehicle usage. Always consult your owner's manual for model-specific recommendations.