51t’s for the best that the 2020 BMW Z4
convertible, particularly in six-cylinder
M40i guise, is essentially a decapitated
2020 Toyota Supra, a car that was co-devel-
oped with the BMW and shares virtually all
of its mechanical identity. The latest Supra
might not be enough of a Toyota for loyalists, but it is no slouch [see “Deep
Roots, Long Shadows,” page 20]. There’s a lot of performance baked into
the new platform to bolster the Z4’s sports-car credentials. We’d be cool
with BMW making the Z4 drive even more like the Supra.
From our prior experience with the entry-level Z4 sDrive30i, when it lost
to the Porsche 718 Boxster in a comparison test, we know that the BMW
is a highly athletic and agile roadster in need of better steering and either
more power or less mass. Stepping up to the M40i handily fixes the latter
issue, replacing the standard 255-hp turbo four-banger with a turbocharged
3.0-liter inline-six good for 382 horsepower and 369 pound-feet of torque.
Wonderfully smooth and willing to rev, BMW’s B58 six is a honey, bring-
ing the Z4 to life with a 1600-rpm torque peak and pulling like a mule to its
6500-rpm redline. The melody of its intake growl overlaid with the refined
snarl of the Z4’s exhaust, especially with the
top down, never gets old, although the active
exhaust system emitting pops and gurgles in
the sportier drive modes seems a bit juvenile
considering the Bimmer’s price.
With its ZF eight-speed automatic shuf-
fling through the gears, the Z4 M40i bolts to
60 mph in 3.8 seconds and covers a quarter-
mile in 12.3, smashing the 30i model’s times by
1.3 and 1.5 seconds, respectively. At a meaty
3535 pounds, however, the M40i weighs 128
pounds more than its lesser sibling, and it’s
376 pounds heavier than its key rival, the 350-
hp Porsche 718 Boxster S. When fitted with its
optional seven-speed dual-clutch automatic,
that Porsche is quicker than this BMW. It’s also
a purer sports car and comes standard with a
six-speed manual.
Aided by its adaptive M Sport dampers, upgraded brakes, and limited-
slip differential, as well as the optional 19-inch Michelin Pilot Super Sport
summer tires (18s are standard), the hot Z4 impresses with a 148-foot stop
from 70 mph and 1.02 g’s of stick around the skidpad, pretty much in line
with the last PDK-equipped Boxster S we tested. Yet finding the BMW’s
flow on a good road is elusive. Its ultrareactive steering speaks in whispers
and its rear end breaks loose with abrupt throttle inputs. At a more relaxed
pace, you’ll find ride compliance and a quiver-free structure. The only thingSPF 40i
TESTED BMW’s 2020 Z4M40i is basically a Toyota
Supra for sun worshipers.
_by Mike Sutton2020 BMW Z 4 M 40 i
VEHICLE TYPE: front-engine, rear-wheel-drive,
2-passenger, 2-door convertible
PRICE AS TESTED: $73,295
BASE PRICE: $64,695
ENGINE: turbocharged and intercooled DOHC
24-valve inline-6, aluminum block and head,
direct fuel injection
DISPLACEMENT: 183 cu in, 2998 cc
POWER: 382 hp @ 6500 rpm
TORQUE: 369 lb-ft @ 1600 rpm
TRANSMISSION: 8-speed automatic with
manual shifting mode
DIMENSIONS
WHEELBASE: 97.2 in
LENGTH/WIDTH/HEIGHT: 170.7/73.4/51.4 in
PASSENGER VOLUME: 52 cu ft
TRUNK VOLUME: 10 cu ft
CURB WEIGHT: 3535 lbC/D Test Results
ZERO TO 60 MPH: 3.8 sec
ZERO TO 100 MPH: 9.1 sec
ZERO TO 130 MPH: 15.9 sec
ROLLING START, 5–60 MPH: 4.5 sec
1/4-MILE: 12.3 sec @ 116 mph
TOP SPEED: 165 mph (governor limited, C/D est)
BRAKING, 70–0 MPH: 148 ft
ROADHOLDING, 300-FT-DIA SKIDPAD: 1.02 g
FUEL ECONOMY
EPA COMBINED/CITY/HWY: 26/24/31 mpg
C/D OBSERVED: 20 mpgI
DRIVELINESSoulful
turbo six,
properly
quick and
grippy, broad
range of
talents.
Heavy for
its class,
indifferent
steering,
Toyota tuned
this car
better.spoiling your sunbathing is a fair amount of
wind turbulence swirling into the cabin over
your shoulder.
Whether or not you approve of the BMW-
Toyota mash-up, Munich made good on the
arrangement by imbuing the best Z4 ever
with a broad array of performance capabilities.
That the M40i only partially addresses the
Z4’s shortcomings, though, is but one of two
reasons why we’d hesitate to pay its $64,695
base price, let alone our test car’s $73,295
sticker. The other reason wears a Porsche
emblem on its nose, even if it does cost about
eight grand more to start.If the Z4’s cockpit
looks familiar,
perhaps you’ve
recently read a
caption about the
Toyot a Su p r a’s
interior. It’s déjà vu
all over again.Z4 photography by MARC URBANO