Car and Driver - USA (2020-05)

MYTH BUSTING

Ready to win the debate in your car over who

controls the thermostat? Using a fistful of

thermocouples and an infrared thermometer,

we tested a few climate-control features in hopes of settling

some disagreements. You’re welcome. —Dave VanderWerp

Heated Debate

SINCE

1956

Does a car’s cabin warm up quicker when

the automatic climate control is set to

a high temperature? No. Now stop it.

THE TEST: Two BMW M340i sedans at idle

with automatic climate control engaged,

one set to 72 degrees, the other set to high.

Both starting temps are 35 degrees.

Note: The sooner the car’s engine

warms up, the quicker the cabin warms up.

The blue line below shows how driving the

car (average speed 39 mph) compares with

letting it idle.

Can the interior temperature vary across the front

row as promised by dual-zone controls?

THE TEST: A BMW M340i with the driver’s side set

to 63 degrees and the passenger’s side set to 83 degrees.

A BMW X7 offers five

separate climate-control

zones. Is there really

a quintet of distinct

temperature bubbles

within the X7’s 14 2 cubic

feet of passenger space?

Sort of.

The maximum temperatures

of heated seats and steering

wheels vary widely from model

to model. Who likes it luke-

warm? Probably the lawyers.

Max Steering-Wheel Temps, °F

79 VW Tiguan

84 GMC Sierra 1500

87 Subaru Forester

92 Honda CR-V

97 Volvo V60 CC

99 BMW X5 M50i

109 Ram 1500

0 10

45

0

250

35

55

65

75

Te

m

pe

ra

tu

re

,^ °

F

Ra

ng

e,^

Mi

Time, Min

20 30

86

71 Subaru Forester

78 Volvo V60 CC

81 Mazda CX-

81 VW Tiguan

84 Honda CR-V

87 Genesis G

87 Mini Cooper S

Countryman

87 Ram 1500

89 Tesla Model 3

91 GMC Sierra 1500

94 BMW X5 M50i

97 Porsche Cayenne

103 Ford Escape

Each Zone Set to a

Different Temp

(Set/Actual Temp, °F)

Max

Seat-Cushion

Temps, °F

How much does using the heat

affect an EV’s range?

THE TEST: A Tesla Model 3 (on winter

tires) going 70 mph on a 38-degree day

with the HVAC off, at 72 degrees, and at

max heat (including all heated seats).

Climate 72 ̊ Auto Max

Control Off

7 2 ̊ Auto

HI Auto

7 2 ̊ Auto

(while driving)

234

200

173

Predicted Range

All Zones Set to the

Same Temp

(Set/Actual Temp, °F)

Actual Temps across the Cabin, °F

33 .7 Min

29 .6 Min

Cabin Warm-Up Times

7 2/ 87 7 2/ 87

7 2/ 87 7 2/ 88

7 2/ 87

60 / 75 65 / 75

70 / 84 75 / 85

80 / 86

81 82 82 86 88 88

16 ILLUSTRATIONS BY CLINT FORD ~ MAY 2020 ~ CAR AND DRIVER

9 .8 Min