2017 Mercedes-Benz GLS

2017 is the first GLS-badged year of the X166 second generation, the facelift and rename of the GL-Class. The volume GLS 450's 3.0L twin-turbo V6 makes 362 hp.

The GLS 450's twin-turbo V6 makes 369 lb-ft, with no electric assist (EQ Boost arrived with the 2020 X167).

KBB lists 6.5 s for the 2017 GLS 450, though another aggregator claims 5.7 s. The more conservative, better-sourced figure is used. Either way the time is adequate rather than quick for a roughly 5,400 lb three-row SUV.

The twin-turbo V6 is smooth and quiet with modest turbo lag, but stop-start is somewhat abrupt. Range Rover and V8 rivals feel more effortless, and the GLS 550 V8 is the stronger choice within the range.

New for the 2017 facelift, the 9G-Tronic 9-speed shifts smoothly in normal driving but can be slow to kick down and sometimes hesitates from a stop. The AMG GLS 63 keeps the 7-speed.

Every 2017 GLS trim is rated to 7,500 lbs with the factory hitch, near the top for unibody luxury SUVs. Body-on-frame Navigator and Escalade tow more.

4MATIC full-time AWD is standard on every 2017 GLS. The optional Off-Road Engineering package adds a two-speed transfer case with low range and a locking center differential.

Standard AIRMATIC air suspension can raise ride height for real clearance, and low range is optional. It is still a road-biased luxury SUV with no axle lockers and no dedicated off-road trim.

There are three gas engines (V6, V8 and AMG V8), with no hybrid, PHEV or US diesel for 2017. That covers a wide output range but offers no electrification.

The twin-turbo V6 GLS 450 is EPA-rated at 19 MPG combined for 2017.

The volume trim's EPA city rating is 17 MPG.

The volume trim's EPA highway rating is 22 MPG.

EPA publishes no range for gas vehicles, so this is derived from EPA's 19 MPG combined × the X166's 26.4-gallon tank. The large tank offsets the low economy.

EPA's annual fuel cost estimate for the 2017 GLS 450 is very high, driven by 19 MPG combined and the premium-fuel requirement.

Every 2017 GLS requires premium unleaded, and there is no regular-fuel, flex-fuel or diesel option in the US.

NHTSA lists the 2017 GLS-Class SUV 4WD but every rating reads 'Not Rated', so the framework value is 0 (never rated). NHTSA never crash-tested the X166 generation.

IIHS never crash-tested the X166 GL/GLS, so the 2017 GLS has no award and no crashworthiness results. 2017 was the facelift-and-rename year of a 2013-era design that predates the newer small-overlap tests, so there are no known structural concerns but also no published validation.

The volume GLS 450 comes standard with COLLISION PREVENTION ASSIST PLUS (radar forward collision warning with autonomous braking), ATTENTION ASSIST, Crosswind Assist, PRE-SAFE and a rearview camera. Blind-spot monitoring, adaptive cruise, lane keeping and cross-traffic functions all cost extra, mostly through the optional Driver Assistance Package. That is thin standard content for a luxury flagship.

IIHS published no front crash prevention result for the GLS. Standard COLLISION PREVENTION ASSIST PLUS brakes autonomously for vehicles. Pedestrian detection (PRE-SAFE Brake) and BAS PLUS need the optional Driver Assistance Package, and there are no night or pedestrian test results.

Blind Spot Assist is optional on the volume GLS 450. Active Blind Spot Assist, which brakes one side to stop a lane change, and BAS PLUS with Cross-Traffic Assist come only in the optional Driver Assistance Package.

Lane departure warning is optional, and Active Lane Keeping Assist and DISTRONIC PLUS Steering Assist come only in the Driver Assistance Package. When fitted, Steering Assist works on well-marked highways but needs more hands-on correction than the later MBUX-era Active Steering Assist.

The optional DISTRONIC PLUS works across the full speed range, including stop-and-go, and adds Steering Assist. It is the previous-generation system, and only conventional cruise control is standard, so a base GLS 450 can be bought without adaptive cruise.

The 2017 GLS has no hands-free highway driving. Its most advanced option, DISTRONIC PLUS Steering Assist, requires hands on the wheel, and Mercedes never offered a hands-free mode on the X166.

The 2017 facelift brought LED headlamps with the Intelligent Light System and Adaptive Highbeam Assist. IIHS never rated the X166 headlights, so with no published result the score stays below the Good-rated band.

The tall, upright greenhouse and high seating position give good forward and side sightlines. Thick rear pillars and third-row headrests create rear blind zones. Only a rearview camera is standard; the 360-degree camera that compensates is optional.

The second-row outboard seats have LATCH lower anchors and the third row has top tethers. Large rear doors and a wide second-row bench make car-seat installation fairly easy, though the anchors sit somewhat deep in the seat bight. IIHS never published a LATCH rating for the X166.

2017 is the first year of the facelifted X166 second generation under the GLS name (formerly GL-Class). Every trim seats seven with a power-folding third row.

Front headroom is generous, typical of the tall, boxy X166 body.

The quoted front legroom is short for a full-size SUV, although reviewers do not flag the front seats as cramped.

The second row has ample headroom for adults.

Second-row legroom is competitive but not class-leading next to body-on-frame rivals such as the Escalade ESV.

The X166 has one of the more usable third rows among European luxury three-row SUVs, with power-folding seats; reviewers call the second and third rows roomy. Tall adults are still squeezed on long trips, and getting in requires tipping the second row forward.

There is respectable space behind the second row and usable space behind the third (16 cu ft), but it trails body-on-frame rivals like the Escalade and Navigator.

A maximum hold of nearly 94 cu ft is large for a unibody luxury SUV.

Everyday bins and console storage are conventional, although the 2017 facelift revised the center console. The power-folding third row and power liftgate help, but there is no standout storage innovation.

The front seats are supportive and power-adjustable, and the optional multicontour seats are excellent. The second row is comfortable. The third row has adequate cushion height but is not adult-friendly for long hauls.

Standard AIRMATIC self-leveling air suspension, improved with the Adaptive Damping System for 2017, gives a cushy, composed highway ride. Large optional wheels add some impact harshness.

The cabin is quiet at highway speed with little wind noise. It hushes tire roar a step less well than the later X167 and the Range Rover.

Heated front seats are standard. Ventilated or massaging seats, heated rear seats and a heated steering wheel come in packages, and multi-zone climate covers the rear.

2017 is the facelift year in which the X166 GL-Class was renamed GLS. The entry GLS 450 4MATIC listed at $68,700 plus $925 destination, which is above the $65,000 SUV band ceiling.

The GLS 450 was the volume trim. Dealer-stock units commonly carried the Premium and Driver Assistance packages plus metallic paint, which added roughly $5–6k to the $69,625 delivered base.

CarEdge puts GLS maintenance near $5,000 over five years, and maintenance-plus-repair estimates for the GLS 450 run near $8,700. The X166 has AIRMATIC air suspension, with known air-strut and compressor repair exposure, and comes with no complimentary scheduled maintenance, so the estimate sits at the top of the range.

iSeeCars reports that the GLS loses 55.8% of its value over five years, which leaves about 44% retained. Current KBB private-party values of about $15–17k for a nine-year-old 2017 GLS 450 confirm that this generation depreciates steeply.

Mercedes-Benz's New Vehicle Limited Warranty runs 4 years or 50,000 miles. That is par for German luxury brands.

Mercedes-Benz offers no separate, longer powertrain warranty. The drivetrain is covered only by the 4-year/50,000-mile basic warranty, which is below the 5-year band floor.

The 2017 GLS includes no complimentary scheduled maintenance; prepaid plans are sold separately. Perks are 24/7 Roadside Assistance for the warranty term and an mbrace connected-services trial, which is thin for a $70k SUV. The 2017 BMW X5 had free scheduled maintenance (BMW Ultimate Care) for 3 years/36,000 miles.

$75,000 volume-trim price minus its estimated resale value after 5 years (44% retained, or about $33,000) leaves about $42,000 in depreciation. Add the projected $9,500 in 5-year maintenance and repairs, and owning this vehicle for 5 years costs about $51,500 in total.

MY2017 is the first year of the facelifted, renamed GLS on the X166 platform, which launched for MY2013. The base platform was mature, but the refresh added new parts, including the 9G-Tronic gearbox across the line, and launch-year GLS units drew more recalls than the 2018. Owner and aggregator ratings are favorable, and the AIRMATIC air suspension is the failure cited most often. Overall it is average for the segment, slightly below the 2018.

Mercedes-Benz places mid-pack to lower-mid in both J.D. Power's Vehicle Dependability Study and Consumer Reports' brand rankings. It ranks ahead of Land Rover, but behind Lexus and usually BMW.

Eight NHTSA campaigns cover the 2017 GLS450, twice the 2018's four. Several touch safety systems: windshield bonding that could affect the passenger airbag (17V655000), a center console that could unlatch in a crash (17V077000), a door-lock indication fault (17V816000), and oil foaming out of the Active Curve System reservoir, a fire risk on equipped trucks (18V272000). The rest are eCall software fixes. There are no engine or transmission campaigns, but the pattern is busier than typical.

The volume GLS 450 4MATIC uses the M276 3.0L biturbo V6 (362 hp), paired from MY2017 with the 9G-Tronic 9-speed, which was new to this model that year. Both are high-volume Mercedes units, and MY2017 has no powertrain recalls. Earlier M276 builds had camshaft-adjuster and timing-chain complaints, oil leaks are common with age, and the first-year 9-speed pairing adds some risk, so the family is mixed rather than proven.

The X166 cabin uses wood, leather and soft-touch surfaces throughout and is solidly assembled. The 2017 refresh added a larger free-standing 8-inch COMAND screen and a new steering wheel, but the button-heavy console still looked dated. It is rich for the class, just not class-leading.

Built at MBUSI in Tuscaloosa on a fifth-year platform, the 2017 GLS is generally well assembled, and owners report only scattered rattles. Two launch-year campaigns trace to assembly, though: excess bulkhead insulation affecting the windshield bond, and a center-console latch that fails FMVSS 201. Both suggest slightly weaker process control than in the 2018.

Mercedes-Benz has one of the densest luxury dealer networks in the US, with roughly 380 dealers and mature service operations. Its service-satisfaction results are competitive within the luxury segment.

Parts are plentiful, and the high-volume M276/9G-Tronic powertrain has decent aftermarket support. Mercedes repair costs are still well above average: AIRMATIC struts and compressors, Active Curve System hydraulics and COMAND electronics are costly fixes, and every 2017 GLS is long out of its 4-year/50,000-mile warranty.

The 2017 GLS uses a non-touch 8-inch freestanding media display, driven by the console controller and a touchpad added with the facelift. MBUX touchscreens arrived only with the X167 for 2020.

The pre-MBUX COMAND interface is dated, with clunky touchpad and rotary input and deep menus. Cars.com specifically criticizes the knob/touchpad control of the 8-inch display.

For 2017, wired Apple CarPlay was optional only and Android Auto was not offered in the US. Wireless projection was never available on the X166.

COMAND navigation is optional on the GLS 450 (Premium Package). Voice control is command-based: functional but rudimentary.

The base audio is decent. harman/kardon LOGIC7 surround is available, with Bang & Olufsen BeoSound at the top of the range.

The cluster is analog gauges flanking a small center multifunction display. A full-digital cluster came only with the X167.

There is no meaningful over-the-air update capability. Map updates come through a navigation service or the dealer.

The mbrace / Mercedes me app covers remote lock, locate and vehicle status. It is subscription-based, and there is no digital key.

Power is USB-A and 12V outlets only, with no USB-C and no wireless charging on the 2017 X166.

KEYLESS GO proximity entry comes in the Premium Package on the GLS 450, and the power liftgate is standard. There is no phone-as-key.

A rearview camera is standard. Surround View and Active Parking Assist come in the optional Parking Assistance package.

No head-up display was offered on the X166 GLS. The X167 added one for 2020.

Seven seats, big rear doors and a power-folding third row make family duty easy. Cargo shrinks to 16 cu ft with all rows up, and the tall step-in is a stretch for small kids.

There are no NHTSA or IIHS crash tests for the 2017 GLS. COLLISION PREVENTION ASSIST PLUS is standard, but blind-spot and lane-keeping assist are in the optional Driver Assistance Package.

A quiet, cushy air-suspended ride and a usable third row make it a strong long-trip hauler. Rear amenities are adequate, but luggage space with all seven seats filled is limited.

It is smooth and calm in traffic, but the 9-speed can hesitate and stop-start is less polished. Its sheer size takes concentration in town.

At 17/22/19 MPG on premium fuel, the V6 GLS 450 is expensive to commute in (EPA about $4,250/yr in fuel).

A long body on a 121-inch wheelbase and a 40.7 ft turning circle make it cumbersome in cities. Surround View camera help is optional, not standard.

A 7,500 lb tow rating, a twin-turbo V6 and a 94 cu ft maximum hold handle moderate towing and hauling. It is a luxury SUV, not a work tool.

It is luxury-oriented and not built for abuse. X166 AIRMATIC strut and compressor failures are a known expense under heavy use.

There is no onboard power, no bed and no work-focused features beyond a trailer hitch and roof rails.

It is a quiet, comfortable mile-eater with roughly 500 miles of range from the 26.4-gal tank. DISTRONIC PLUS with Steering Assist is an option, not standard.

Standard 4MATIC AWD, a raisable air suspension, a 7,500 lb tow rating and roof rails make it a capable all-weather tourer. The optional Off-Road Engineering Package adds low range.

The second and third rows fold flat to nearly 94 cu ft, and a tow hitch and roof rails add flexibility.

It is secure and stable but heavy and softly tuned. There is noticeable roll in the GLS 450, which lacks the Active Curve System of higher trims.

The electric power steering is precise enough but light and numb, typical of a large luxury SUV.

The brakes are adequate for a roughly 5,400 lb SUV, with a progressive pedal. No instrumented stopping data for the 2017 model was found.

The twin-turbo V6 is smooth with modest turbo lag. The 9-speed new for 2017 shifts smoothly but is sometimes slow to kick down, and stop-start can be abrupt.

The V6 is well isolated and unobtrusive under load. The GLS 550 V8 adds a pleasant, muted burble.

The turning circle is large, reflecting the 121.1-inch wheelbase.

The upright, commanding seating position gives good sightlines. The COMAND knob/touchpad and column-mounted shifter take some adjustment.

The GLS 450 is pleasant but more serene transporter than engaging drive. The GLS 550 and AMG GLS 63 add real character.

The 2017 GLS 450 comes standard with 4MATIC, AIRMATIC air suspension, the new 9G-TRONIC 9-speed automatic, a power-folding third row, collision-prevention braking and Pre-Safe. However, adaptive cruise, active lane assist and the 360° camera were in the optional packages, which is typical German option pricing.

At $69,625 delivered, the GLS 450 undercut the Escalade, Land Cruiser and LX, with an adult-usable third row, 7,500-lb towing and a 362-hp engine. However, driver aids cost extra and the facelift's COMAND tech was only a modest update.

There are three well-spaced US trims, the V6 GLS 450 ($68,700), the V8 GLS 550 ($93,850) and the AMG GLS 63 ($124,100), plus a deep option list. All are 4MATIC and gas-only, since the official 2017 lineup lists no GLS 350d diesel.

In 2017, when the renamed GLS was a steady US seller, it sold roughly 30,000 units a year. It faced no BMW X7 yet and outsold the Lexus LX, Infiniti QX80 and the old Lincoln Navigator, though it trailed the Escalade.

The GLS, which the 2017 rename positioned as the 'S-Class of SUVs', is the flagship of Mercedes-Benz's SUV range, and Mercedes-Benz remains one of the strongest luxury brands. Steep depreciation shows the image does not fully carry into resale.

As a late-cycle German luxury SUV in a normal pre-pandemic market, the 2017 GLS commonly drew lease support and dealer discounts below MSRP, with roughly $4–5k between invoice and MSRP to negotiate with.

2017 was a refresh year: the X166 got a facelift, the GLS name, a 9-speed automatic and updated COMAND with a larger screen. However, the generation dated to 2013 and was replaced by the X167 for 2020, so buyers got a mid-to-late-cycle platform.

Reviewers credited the refreshed GLS with a comfortable ride, a usable third row and strong engines, but noted its dated interior tech next to newer rivals. It won no major awards and had no full NHTSA or IIHS crash rating.