The X167 GLS is Mercedes flagship 3-row luxury SUV — a genuine S-Class on stilts with optional E-Active Body Control suspension. Air suspension compressor failure is the primary mechanical concern. The M256 I6 with 48V EQ Boost is smooth and efficient; the GLS 580 V8 is powerful but expensive to maintain. Only buy with full Mercedes dealer records and CPO coverage.
Items to check
11
Open recalls
1
NHTSA complaints
180
Top concern
Air Suspension / Engine / Electrical
Air Suspension
Air suspension compressor failure
High Risk at 50k+
GLS Airmatic compressor fails at similar rate to GLE. Very expensive on this platform.
Overnight level test. Any corner sag = compressor failing.
Est. cost: $2,000–$4,000 compressorSource: Mercedes X167 air suspension pattern
Powertrain
M256 I6 EQ Boost — preferred
Low Risk
Inline-six with 48V mild hybrid is the better long-term ownership choice.
Standard oil check. Test all driving modes.
Est. cost: Higher maintenance costSource: Mercedes M256 reliability
GLS 580 V8 — powerful but expensive
Monitor
Biturbo V8 is exceptional but maintenance costs are very high.
Full oil check and cold-start test.
Est. cost: Very high maintenance costSource: Mercedes AMG V8 ownership cost
Maintenance Cost
MB service records — mandatory
High Risk without
GLS services run $2,000–$3,500 per interval.
Request ALL MB dealer records. No records = walk.
Est. cost: $2,000–$3,500 per serviceSource: AutoVetting editorial
Documentation
CPO status + recall check
High Risk without
MB CPO is essentially mandatory on a GLS.
Verify CPO at MB dealer. Run VIN at nhtsa.gov/recalls.
Independent pre-purchase inspection — we arrange it and walk you through the findings.
Send us the listing and we reply within 1 business day. Nothing due until we confirm a mechanic and a time. Piloting in Phoenix; other US metros by arrangement.
The Vetting Report: this VIN’s full recall status, known-failure cost ranges, negotiation talking points, and inspection priorities — delivered within 24 hours.