Acceleration

SL550	SL600	Class Average
7	10	8.1

SL550 gathers speed rapidly, shows true authority above 40 mph, and feels equal to Mercedes's 5.3-second 0-60-mph claim. SL600 is stronger still. Its claimed 4.5-second 0-60 mph time feels right to us. No AMG versions have been made available for us to test, but Mercedes pegs them at less than 4.5 seconds 0-60 mph.

Fuel Economy

SL550	SL600	Class Average
2	1	4.2

No opportunity yet to measure. All SLs require premium-grade gas.

Ride Quality

SL550	SL600	Class Average
6	6	4.4

Any SL displays a fine blend of firm control and astute bump absorption. There's a bit more jarring than expected on really rough pavement. There's virtually no cowl shake with the top down.

Steering/Handling/Braking

SL550	SL600	Class Average
8	8	8.7

Great balance in turns, natural steering feel, and good grip. High-speed stability also impresses. Simulated panic stops produced shorter than average distances. The brake-by-wire system furnishes inconsistent stopping action from town speeds and excessive initial pedal travel from higher speeds.

Quietness

SL550	SL600	Class Average
6	6	4.2

Top-up, 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. The engines sound refined. They're mostly hushed at idle and little louder at full throttle.

Controls

SL550	SL600	Class Average
6	6	5.6

Sporty, sophisticated dashboard, though the speedometer and tachometer are obscured by glare in some lighting conditions. SL has an abundance of buttons and switches, though all are easy to reach. The navigation system complicates some audio and climate settings, and most adjustments require multiple inputs. Pop-out cupholders obscure the navigation screen and nearby climate controls.

Details

SL550	SL600	Class Average
8	8	6.9

The cabin's high-grade materials are mostly appropriate for the lofty prices; exceptions are flimsy sun visors and a few bits of hard plastic cabin trim. Top powers in and out of the trunk area in 16 seconds.

Room/Comfort/Driver Seating (front)

SL550	SL600	Class Average
8	8	5.8

Hard to fault, with stretch-out space and supportive, comfortable seats. SL's low-slung body and long doors complicate entry and exit.

Room/Comfort (rear)

SL550	SL600	Class Average
0	0	.7

(No rear seating.)

Cargo Room

SL550	SL600	Class Average
3	3	2.6

Trunk has 10.2 cu ft with the roof raised and 7.3 with it lowered, enough for two small golf bags. When stowed, the top pivots for access to items in the trunk bottom. Cabin storage is pretty meager overall, but it does include covered bins behind the seats.

Value within Class

SL550	SL600	Class Average
6	3	5.3

SLs are intriguingly engineered, 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 startling sticker prices.

Total Score

SL550	SL600	Class Average
60	59	56.5

Scores for all Premium Sporty/performance Cars

Low Score		39
Average Score		56
High Score		65