Premium sporty/performance car; Built in Germany
  • 2-door convertible
  • longitudinal front-engine/rear-wheel drive
Good condition price range: $18,000 – $141,000*

2004 Mercedes-Benz SL-Class

2003 Mercedes-Benz SL-Class

2004 Mercedes-Benz SL-Class

2003 Mercedes-Benz SL-Class

  • Acceleration
  • Build quality
  • Seat comfort
  • Steering/handling
  • Instruments/controls
  • Brake-pedal feel

Intriguingly engineered, the current SLs are solidly built, impeccably finished, and a pleasure to drive. Their style and cachet should stay fresh for years, boosting long-term resale values and taking some sting out of the startling new-car sticker prices. Of course, that’s not good news for used-car shoppers, who can expect to plenty for a secondhand SL.


A redesigned SL500 bowed as an early 2003 model. Soon, it was followed by an SL55 AMG version with styling, chassis, and powertrain modifications by Mercedes’ in-house performance team. These two-seat rear-drive convertibles were slightly longer, lower, and wider than the 1990-2002 models. Yet, they were some 125 pounds lighter. A retractable metal hardtop replaced the prior cloth folding top.

The SL500 retained a 5.0-liter V8, but the SL55’s 5.4-liter V8 was newly supercharged for an extra 104 horsepower over the previous engine. Both SLs had a five-speed automatic transmission with manual shift feature. The SL55 used a special “SpeedShift” unit with performance programming and steering-wheel shift buttons.

Both models came with an traction/antiskid control and Mercedes’ ABC active suspension, designed to reduce cornering lean. A shared industry-first was antilock four-wheel disc brakes with “brake-by-wire” technology that modulated hydraulic pressure to each wheel by computer signals. Both SLs also came with head/torso side airbags, a driver knee airbag, and a rollover bar that popped up if sensors detected an impending tip. Additional standard equipment included navigation and assistance systems, and a second battery mounted in the trunk to run power accessories.

The SL55 had 18-inch wheels instead of 17s, plus higher-speed low-profile tires that were wider at the rear than at the front. Options for both SLs included a tire-pressure monitor; high/low-beam xenon headlamps; radar cruise control designed to maintain a set following distance; and ventilated/massaging seats. Mercedes’ available Keyless Go system used a credit-card-sized transmitter for unlocking and starting the car simply by touch. Voice control for audio, phone, and other functions was available through dealers. Two-passenger competitors included the Cadillac XLR and Lexus SC 430.

Yearly Updates

2004 SL-Class
A 12-cylinder SL600 flagship model debuted for 2004, along with a seven-speed automatic transmission. Installed only in the SL500, the seven-speed was an industry first. During up and down shifts, it could skip gears for increased efficiency. Other models retained Mercedes’ five-speed automatic. All models were now pre-wired for optional dealer-installed satellite radio. The Keyless Go option now took its signal from a keyboard instead of a pass card.
2005 SL-Class
For 2005, the navigation system and center console were revised. A new limited-production SL65 AMG model was launched, with a 604-horsepower, twin-turbo V-12 engine. In addition to specific styling touches, the SL65 AMG got bigger brakes and 19-inch wheels. The revamped console included an updated version of Mercedes’ COMAND video control for navigation, audio, and climate functions.
2006 SL-Class
Keyless Go, a keyless-entry and starting system, became standard on SL600 and SL65 models, but remained optional for the SL500 and SL55. Run-flat tires now were available for SL500/600 models. Satellite radio joined the options list. The high-performance SL55 AMG could be equipped with a $14,000 AMG Performance Package that included exclusive interior trim and a 186-mph top-speed governor (others were limited to 155 mph).
2007 SL-Class
New for 2007 was the SL550. It replaced the SL500 and had a 382-hp V8 vs. 302 hp.
2008 SL-Class
The 2008 Mercedes-Benz SL-Class received no major changes.
2009 SL-Class
The 2009 Mercedes-Benz SL-Class got freshened styling, a revised interior, and a new performance model. Added for 2009 was the SL63 with a 518-hp 6.2-liter V8. The redesigned interior included a standard navigation system and wireless cell-phone link.
2010 SL-Class
The 2010 Mercedes-Benz SL-Class was largely unchanged.
2011 SL-Class
The 2011 Mercedes-Benz SL-Class lineup saw a few changes, including the addition of a limited-production Night Edition and the deletion of the V12-powered SL600.
2012 SL-Class
The performance-oriented SL65 AMG was dropped from the 2012 Mercedes-Benz SL-Class lineup for 2012, but there were no other changes of note.


longitudinal front-engine/rear-wheel drive

Four powertrains have been available in SL-Class models. A 302-horsepower 5.0-liter V8 engine went into the SL500, mated to a seven-speed automatic transmission. The SL600 held a turbocharged 493-horsepower 5.5-liter V12, with a five-speed automatic. The supercharged 5.4-liter V8 in the SL55 AMG produces the same 493 horsepower but lower torque, and also worked with a five-speed automatic transmission. For 2005, the limited-production SL65 AMG got a 604-horsepower twin-turbo V12. For 2007, the SL550 replaces the SL500 and has a 382-hp V8 vs. 302 hp. Added for 2009 was the SL63 with a 518-hp 6.2-liter V8.

ohc V8
Engine Size (liters/cubic inches) 5.0/303
Engine HP 302
Engine Torque (lb-ft) 339
Avail. Trans. EPA MPG (city/hwy) MPG avg. as tested
7-speed automatic



dohc V8
Engine Size (liters/cubic inches) 5.5/333
Engine HP 382
Engine Torque (lb-ft) 391
Avail. Trans. EPA MPG (city/hwy) MPG avg. as tested
7-speed automatic


Supercharged ohv V8
Engine Size (liters/cubic inches) 5.4/332
Engine HP 493
Engine Torque (lb-ft) 516
Avail. Trans. EPA MPG (city/hwy) MPG avg. as tested
5-speed automatic


Turbocharged ohv V12
Engine Size (liters/cubic inches) 5.5/336
Engine HP 493
Engine Torque (lb-ft) 590
Avail. Trans. EPA MPG (city/hwy) MPG avg. as tested
5-speed automatic


dohc V8
Engine Size (liters/cubic inches) 6.2/379
Engine HP 518
Engine Torque (lb-ft) 465
Avail. Trans. EPA MPG (city/hwy) MPG avg. as tested
7-speed automatic


Turbocharged ohv V12
Engine Size (liters/cubic inches) 6.0/365
Engine HP 604
Engine Torque (lb-ft) 738
Avail. Trans. EPA MPG (city/hwy) MPG avg. as tested
5-speed automatic


Road Test

Although the SL500 isn’t as fast off the line as might be expected, it gathers speed quickly and shows true authority above 40 mph. Mercedes’ 6.1-second claim for 0-60-mph acceleration seemed a trifle optimistic; our testers managed 6.5 seconds. With a claimed 4.5-second time, the SL55 was the fastest Mercedes yet. Until the SL65 arrived, that is, with a 4.2-second claim. The SL600 is strong both from a standstill and for highway passing.

A test SL500 averaged 19.5 mpg in mostly highway driving, so expect less overall. Premium fuel is required.

SL-Class models deliver a fine blend of firm control and astute bump absorption, though they’re more jarring than expected on really rough pavement. Even top-down, the impressively solid SL holds quivers to a minimum.

Handling is nowhere near Porsche-nimble, yet the SL offers fine balance in turns with natural steering feel and good grip. Impressive high-speed stability rounds out the picture; 75 mph feels more like 40 mph. Stopping power is strong, but brake-by-wire furnishes inconsistent deceleration at around-town speeds. The brake pedal has slightly numb feel and, in simulated panic stops, excessive initial travel–but shorter-than-average stopping distances.

Top-up, the SL is as quiet as most any luxury coupe, with little wind noise and almost no tire roar. Top-down, wind rush is well managed at highway speeds. The V8’s rich purr is evident only during rapid acceleration. Engines are hushed at idle, and little louder at full throttle.

Many buttons and switches dot the sporty, sophisticated dashboard, though all are easy to reach. Some testers have complained that pronounced coves failed to shield the speedometer and tachometer from daytime glare. The navigation system incorporates some audio and climate functions, and most adjustments require multiple inputs. Pop-out cupholders obscure the navigation screen and nearby conventional climate controls. The hardtop powers in and out of the trunk area in 16 seconds. High-grade materials and world-class finish are appropriate for this price level, but that’s not true of the flimsy sunvisors and some plastic cabin trim.

Stretch-out space is hard to fault on supportive and comfortable seats, though the low-slung body and long doors mean less-than-ideal entry/exit. Trunk space totals 10.2 cubic feet with the roof raised, 7.3 when it’s lowered–enough for two small golf bags. The stowed top pivots for access to items in the trunk bottom. Cabin storage includes large map pockets and covered bins behind seats.


Model Tested: 2005 Mercedes-Benz SL-Class SL500

Ratings values are on a 1-10 scale, with 10 being the best. With the exception of Value, these numbers reflect how the vehicle compares against the universe of vehicles, not just against rivals in its class.


Acceleration - 7
Fuel Economy - 4
Ride Quality - 6
Steering/Handling - 8
Quietness - 6


Controls/Materials - 7
Room/Comfort Front - 8
Room/Comfort Rear - --
Cargo Room - 2


Value - 6

Total: 54


2-door convertible
Wheelbase (in.) Length (in.) Width (in.) Height (in.) Weight (lbs)
100.8 178.5 71.9 51.0
Cargo Volume (cu/ft) Payload Capacity (cu/ft) Fuel Capacity (gal.) Seating Capacity
10.2 21.1 2
Headroom Legroom
Front Rear Front Rear
37.7 42.9
Safety Ratings

Model Tested: N/A


(5 is the highest rating)

Front Impact Test

Driver Injury - N/A
Front Passenger Injury - N/A

Side Impact Test

Driver Injury - N/A
Rear Passenger Injury - N/A


(A score of 100 is average. Lower is better)

Collision N/A
Injury N/A
Theft N/A

Trouble Spots

Air conditioner
Description: The A/C compressor may cycle on and off too often due to a problem in the sensor for the emission control charcoal canister, sending an erroneous signal across the multiplex bus. (2003)
Ball joints
Description: Noises from the upper control arm caused by bad ball joint caused by torn rubber cover on joint. (2005-07)
Blower motor
Description: The blower motor may quit working after a minute or so, then work momentarily and quit again due to internal circuit breaker in blower regulator which must be replaced. (2005-06)
Blower motor
Description: The blower motor may quit, but run again only to quit again due to a faulty blower motor regulator. (2006-07)
Description: Some vehicles have rotors that warp under hard use, which creates heat. New rotors are heavier and withstand more heat. (2003)
Engine noise
Description: During hard acceleration, there is a noise from the engine that sounds like piston slap and the noise is eliminated by replacing the motor mounts. (2003)
Keyless entry
Description: The battery may go dead due to the pneumatic systems equipment pump running continuously because the “keyless go” and remote trunk opening switches stick. (2007)
Oil leak
Description: Oil leaks from the camshaft caps at the rear of the engine unless improved caps have been installed. (2006-09)
Suspension noise
Description: Banging or thumping noises from the front suspension caused by failure of the spring control arm rubber bushing. (2004-07)
Transmission leak
Description: Fluid may leak from the electrical connector of the automatic transmission. (2003)
Description: Poor battery charging may be due to a bad voltage regulator in the alternator. (2003)
Description: The automatic leveling system may allow the vehicle to lower after extended sitting (approx. a week) due to leak of check valve block(s). Drooping on only one corner is due to dirty hydraulic fluid, which must be replaced along with filter. (2005-06)
Description: Vehicle may lower randomly while driving due to problem with active suspension system due to problems with the body acceleration sensors. (2005)
Transmission problems
Description: The transmission feels like it is shifting harshly between first and second gear or engages harshly into drive or reverse and both conditions should be improved with software upgrades. (2007-09)

Recall History

2003-04 SL-Class
Description: If vehicle is not routinely serviced or brake system has seen heavy use over high mileage, electronic monitoring system of Sensotronic brake control may trigger the hydraulic function mode.
2003-06 SL-Class
Description: Sensotronic brake control system may prematurely shift to hydraulic backup function mode, due to deterioration of wiring harness connection of premature pump failure, resulting in greater pedal travel and required pressure.
Description: An incorrect software calibration number (SCN) coding received during a recent workshop visit can affect a number of functions: (1) the fuel gauge readings may be incorrect; (2) a stuck fuel-level sensor may not be displayed in the instrument cluster; (3) the check engine light may illuminate incorrectly; and, (4) the speedometer may be out of tolerance. In the event of a vehicle crash, the electrical fuel pump may not receive a crash signal that is required for the fuel pump to disconnect and prevent future fuel delivery as designed. Dealers will recode the SCN.
2003-07 SL-Class equipped with Active Body Control (ABC) acceleration sensors on the front struts
Description: ABC sensors on either of the front struts may not transmit body movement data because of inconsistent soldering points. This could result in unexpected body movements at the front axle, which can adversely influence the vehicle’s directional stability and could lead to a vehicle crash. Dealers will inspect and replace, if necessary, the front ABC sensors in all potentially affected vehicles.

Equipment Lists

Equipment lists are only viewable on larger screen sizes.


Used-car pricing varies widely depending on local market conditions. Therefore, we recommend visiting websites that list used cars for sale to get a better idea of what a specific model is selling for in your area.

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