Buyer Research

2018 Mercedes-Benz S450 — Should You Buy One?

Typical asking price: $42,000–$58,000. There are 2 high-severity known issues you need to know before handing over a check.

Kestrel Take

The benchmark luxury sedan — the W222 S-Class is the standard by which all others are judged for comfort, quiet, and technology, and the S450's twin-turbo V6 is efficient for the class. Depreciation makes a used one attainable, but flagship complexity means flagship repair bills. A documented S450 with full history is a peerless, comfortable car; a cheap neglected one is ruinous. Only buy with complete records and a substantial repair fund.

Known Issues for the 2018 Mercedes-Benz S450

Ranked by wallet impact. These are documented, recurring problems — not freak accidents.

Complex flagship electronics / techHigh — wallet impact

The vast electronics and driver-assist systems can fault expensively; verify every system.

Repair cost range: $500-$3,000+

Air suspension (Airmatic)High — wallet impact

The Airmatic air suspension leaks and fails; verify it rides level and holds at all corners.

Repair cost range: $1,000-$3,500

Twin-turbo V6 / cooling / leaksMedium

Verify service and check for oil/coolant leaks and turbo health.

Repair cost range: $400-$3,000

Very expensive service / consumablesMedium

S-Class service, brakes, and tires are very pricey; demand full history.

Repair cost range: Varies (often $$$)

Walk-Away Red Flags

✗No service history (deal-breaker)
✗Airmatic faults / sagging
✗Electronics faults
✗Cheap price hiding deferred maintenance

Good Signs

✓Full documented MB service
✓Airmatic level and holding
✓All electronics working, no leaks

Found a specific Mercedes-Benz S450?

This page covers what goes wrong on the 2018 Mercedes-Benz S450 in general. The Kestrel report covers this specific car— the asking price vs. market, the photos, the seller's description, and a BUY / NEGOTIATE / WALK AWAY verdict with a negotiation script.

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Known issues on this page are based on documented owner reports, NHTSA complaints, class-action records, and manufacturer technical service bulletins. Individual vehicles vary. A pre-purchase inspection by a trusted mechanic is always worth doing.