Page 169 of 481

168 Controls in detailAutomatic transmission*Downshifting
Briefly press button1 on the left side
of the steering wheel.
The transmission will shift to the next
lower gear as permitted by the shift
program. This action simultaneously limits
the gear range of the transmission
(
page 160) when you are driving in the
automatic program mode (CorS).Upshifting
Briefly press button2 on the right
side of the steering wheel.
The transmission will shift to the next
higher gear as permitted by the shift
program. This action simultaneously
extends the gear range of the transmission
when you are driving in the automatic
program mode (CorS).Canceling gear range limit
Press and hold button2 on the right
side of the steering wheel until
D
reappears in the multifunction display.
The transmission will shift from the current
gear range directly to gear rangeD.
Shifting into optimal gear range
Press and hold button1 on the left
side of the steering wheel.
The transmission will automatically select
the gear range suited for optimal
acceleration and deceleration. This will
involve shifting down one or more gears.
Warning!
G
On slippery road surfaces, never downshift
in order to obtain braking action. This could
result in drive wheel slip and reduced
vehicle control. Your vehicle’s ABS will not
prevent this type of loss of control.
Page 300 of 481

299 Operation
Driving instructions
SLK 280, SLK 350
SLK 280 with Sport Package*
SLK 350 with Sport Package*
Your vehicle is factory equipped with
“W”-rated tires, which have a tire speed
rating of 168 mph (270 km / h).
An electronic speed limiter prevents your
vehicle from exceeding a speed of
155 mph (250 km/h).
SLK 55 AMG
Your vehicle is factory equipped with
“Y”-rated tires, which have a tire speed
rating of 186 mph (300 km / h).
An electronic speed limiter prevents your
vehicle from exceeding a speed of
155 mph (250 km/h).SLK 55 AMG with Performance
Package*
Your vehicle is factory equipped with
“Y”-rated tires, which have a tire speed
rating of 186 mph (300 km / h).
An electronic speed limiter prevents your
vehicle from exceeding a speed of
174 mph (280 km/h).
Winter driving instructions
The most important rule for slippery or icy
roads is to drive sensibly and to avoid
abrupt acceleration, braking and steering
maneuvers. Do not use the cruise control
system under such conditions.
When the vehicle is in danger of skidding,
move gear selector lever* to positionN or
declutch in case of manual transmission.
Try to keep the vehicle under control by
corrective steering action.
iFor information on speed rating for
winter tires, see “Winter tires”
(page 348).
For additional general information on
tire speed markings on tire sidewall,
see “Tire speed rating” (
page 334).
iFor information on driving with snow
chains, see “Snow chains”
(page 349).
Warning!
G
On slippery road surfaces, never downshift
in order to obtain braking action. This could
result in drive wheel slip and reduced vehi-
cle control. Your vehicle’s ABS will not pre-
vent this type of control loss.
Page 338 of 481

337 Operation
Tires and wheels
Summer tires
At the tire manufacturer’s option, any
tire with a speed capability above
149 mph (240 km/h) can include a
“ZR” in the size designation (for exam-
ple: 245/40 ZR18). To determine the
maximum speed capability of the tire,
the service description for the tire must
be referred to.The service description is comprised of
the tire load rating5 (
page 334)
and the tire speed rating6
(
page 334).
If your tire includes “ZR” in the size
designation and no service
description5 and6 (
page 334) is
given, the tire manufacturer must be
consulted for the maximum speed ca-
pability.
If a service description5 and6
(
page 334) is given, the speed capa-
bility is limited by the speed symbol in
the service description.
Example: 245/40 ZR18 97Y.
In this example, “97Y” is the service
description. The letter “Y” designates
the speed rating and the speed capabil-
ity of the tire is limited to 186 mph
(300 km/h).
Any tire with a speed capability above
186 mph (300 km/h) must include a
“ZR” in the size designation AND the
service description must be placed in
parenthesis. Example: 275/40 ZR 18
(99Y). The “(Y)” speed rating in paren-
thesis designates the maximum speed
capability of the tire as being above
186 mph (300 km/h). Consult the tire
manufacturer for the actual maximum
permissible speed of the tire.
Index
Speed rating
Q
up to 100 mph (160 km/h)
R
up to 106 mph (170 km/h)
S
up to 112 mph (180 km/h)
T
up to 118 mph (190 km/h)
H
up to 130 mph (210 km/h)
V
up to 149 mph (240 km/h)
W
up to 168 mph (270 km/h)
Y
up to 186 mph (300 km/h)
(Y)
above 186 mph (300 km/h)
ZR
above 149 mph (240 km/h)