Review: 2020 BMW Z4 M40i — Luxury, Style, And Lots Of Muscle

There’s been a lot of buzz surrounding the new 2020 BMW Z4. Though, none of it directly tied to the Z4 itself, but rather its hotly-anticipated chassis-mate, the Mark 5 Toyota Supra. The internet has been a brutal, volatile place of opinions, suppositions, and hypotheses about these two cars, with a lot of the negativity behind statements like “the Supra is just a BMW Z4” and “lol wow I like this Toyota Supra convertible. I know for sure this is the most original Supra joke that's ever been uttered, it's definitely my ticket to standup comedy fame". Well, maybe the latter is a tad hyperbolical.

We’re here to ask: how is it a bad thing that they’re the same chassis? Addressing the haters, our Editor in Chief Tom Martin put it best: the mysticism of non-experience. We’ll analyze the upsides and downsides of the Supra and how it compares in a future article, as we got our hands on one literally an hour after the Z4. To start out though, here’s why the Z4 is a great car, and a great choice to “base” the Supra on.

We were given a week-long go in a 2020 BMW Z4 M40i, which was spec’d incredibly high and had the most power available across its several trims. Price on the dealer lot worked out to $73,295, with various tech and luxury packages added on. The Frozen Grey II Metaillic paint was a $3,600 option, the Driving Assistance Package came in at $500, the Premium Package threw on another $1400, and finally the Executive Package buttoned it all up at $2,500. Base price: $63,700. Huge thanks to BMW USA for letting us have a go!

Exterior And Interior

At a non-descript industrial park in Torrance, California, our rep threw us the keys to what would be a whole week of top-down Southern California fun. As we approached the slick Bavarian convertible, we were greeted by its beautiful-yet-understated figure. With classic sports car design integrated into its modern angles and lines, covered in a beautiful satin silver paint job, the overall look is very aesthetically pleasing, and possesses the best of modern BMW design language. Opening the big, heavy convertible door, the pleasing experience goes further.

A waft of quality leather and German new-car-smell greeted our nostrils, and the sight of its bright red seats contracted our pupils; entering the Z4 M40i is a real treat. Met with substantial-feeling leather surfaces and controls, one of the thickest steering wheels we’ve ever grasped, and wonderfully-comfortable sport seats, it was one of the most serene interiors we’ve sat in this side of $100,000.

The interior is intuitive. To start, it possesses massive cupholders hidden beneath the center armrest, which reveal themselves to the world via a button mildly hidden in the thick, textured silver center trim. When the driver’s half of the arm rest is closed, they can still access their beverage easily, though the passenger has to reach over the flipped-up piece on their end; how very German to put the driver absolutely first and not be too concerned about the passenger. Everything else in the cabin is very modern BMW, consisting of substantial materials and their brand of infotainment and climate control switches. The stereo system was excellent, and utilized some substantial dash-mounted speakers to bounce sound off the windshield for good convertible acoustics. Our one gripe was needing to access and infotainment menu to turn the air conditioning on and off. Increasing and decreasing fan speed was a tad annoying too, as it required a pretty substantial finger-shove. The logic behind this might be to cut down on accidentally pressing these buttons, but they’re so out of the way that we can’t see that happening often.

The seating position was spot-on: drivers of all shapes and sizes sit nice and low, there’s tons of head clearance for tall folks with the top up or down, and the seat itself had excellent adjustability and bolstering. Plus, the seat can be moved really far back on the rails. With the addition of a manually telescoping steering wheel, we found it possible to achieve a very comfortable driving position, making this an excellent long-distance grand tourer. We did not have much visibility out the rear three-quarter view, though luckily its blind spot monitoring system worked well.

There was a good amount of storage readily accessible in the Z4’s interior: a cargo net behind the seats, a decent-sized glovebox, storage box integrated into the trim behind the rear seats, a small forward console tray equipped with phone charging pad and USB ports, and very small door pockets. The cargo netting came in handy for holding shifting contents during spirited drives on twisty roads. The trunk was also quite large, adding to its grand tourer sensibilities; enough space to satisfy two adults overpacking for a long weekend in Las Vegas.

The Z4’s status as a long-distance grand tourer is further solidified for having great sound buffeting and low wind noise with the windows up and cloth top down, and even better with the top up. Closing or retracting the roof is a cinch, too, as it takes maybe 8 seconds and automatically locks. We received a few odd looks from folks while commuting on Southern California’s freeways in blustery 60-degree weather, but were genuinely impressed at how low wind noise was cruising along at 70 MPH.

On the highway in one of the Sport modes, the piped-in artificial exhaust note through the rear speakers got a tad annoying after a while. The fake tone was slightly off-tempo with the actual exhaust tone, which lightly resembled the sound of a misfire or other mechanical issue. Switching over to any other mode quickly remedied this, and contributed to better fuel economy to boot.

It’s quite apparent that the heated seats were engineered in a country that experiences a lot of cold, damp days, as they came up to temperature quite fast and got very warm; to the degree of (pun intended) slowly walking backwards towards a massive bonfire. This made cold weather commuting with the top down very comfortable, and reminiscent of sitting in an outdoor hot tub at a ski resort… more than we thought could be possible, really.

Engine, Performance, Transmission

The engine under the hood of the Z4 M40i is BMW’s B58M30O1 single twin-scroll turbo I-6. With 382 horsepower available at 6500 RPM, and 369 lb.-ft. of torque ready to shove its occupants back in their seats as early as 1600 RPM, it’s a real beast. Every green light launch, every right-turn onto a large, open street, every corner exit on a twisty canyon road; this engine is silky smooth yet brutal, and makes a beautiful, deep growl all over the tachometer.

We did get a tad annoyed over the fact that one cannot tune out the exhaust burbles and crackles in the Sport modes. We’d love an angry, on-throttle snarl and some very mild popping after a quick lift; its current tune got a bit obnoxious after a while. We certainly get it though. Hopefully either BMW themselves, or the aftermarket come up with a way to cut down on the obnoxiousness.

Naturally, the turbo engine’s intake and exhaust notes are magnificently amplified with the top down. Turning off traction and stability control made for a very balanced, controllable, and tail-happy experience; the most important trait that a good, modern sports car ought to possess.

With launch control and a little courage, the Z can claw its way to 60 MPH in around 3.8 seconds. Sub-4.5 is regularly achievable with little effort, and other sources state it’ll hit 100 MPH in 9.1 seconds. That's right: this 3535 lb. convertible hits triple digit speeds in the same amount of time it takes modest, economy hatchbacks to reach 60 measly MPH.

This is a bit surprising, really, as some vehicles out there with similar power-to-weight ratios can’t get below 4 seconds. We aren’t inclined to get too pedantic and split hairs, but we’re truly fascinated by the Z4 M40i being able to sprint to 60 just a tad slower than some hypercars, from the factory, and for less than $100,000. After a bit of digging, we happened upon this article that states the Z4’s power numbers are not only true wheel-horsepower numbers, but are also very understated. This explains a lot.

Real world experience definitely supports these numbers too, as we may have allegedly reached overnight-in-jail speeds while overtaking semis on the freeway. Definitely a testament to the engine’s smooth power delivery, excellent ride, and highway manners, too. The engine’s block is also a closed-deck design, which makes it suitable for aftermarket tuning that could yield some very massive numbers in the near future.

The ZF 8-speed automatic gearbox bolted up to the 3.0-liter 6 is brilliant. Lightning fast shifts, no drama, excellent ratios for both performance and highway cruising… that’s pretty much all we’ve got. It has proven, and will continue to to prove, itself as an excellent, modular setup across BMW’s ever-growing lineup.

EPA fuel economy for the Z4 M40i is rated at 26 MPG combined, with 24 city and 31 highway. We saw substantially less as it was way too fun to bury our right foot every chance we got. Though, while cruising easy on the highway, we saw a tad better than 31 MPG thanks to its great gearing, and possibly also sportscar aerodynamics.

Suspension, Handling, Brakes, Steering

As expected with any modern BMW and hinted at earlier, the Z4’s wind noise isn’t bad at all for a soft top, and the ride is very good on the highway. Set to either Standard, Comfort, or Eco mode, the Z4 rides with a lot of compliance, albeit in some instances a bit too much, which we suspect is because it’s a convertible. Obviously structural rigidity is decreased in a convertible, and modern chassis engineering is significantly better in this department than it used to be (NA and NB Miatas come to mind first). Though, while piloting the little Bavarian coupe over Southern California’s worst freeway surfaces filled with separations, poorly-filled-in potholes, weird grating we’ve never understood the purpose of, and other topographic annoyances, cowl shake and flex were noticeable.

Elsewhere in the handling department, it all came together well for being a convertible. With multilink suspension all around, and classic sports car dimensions with a lower ride height, the quality of the ride was very good across all modes. When set to Sport and Sport Plus modes, the Z4 changed direction well, exhibited no brake dive, and was a ton of fun on any twisty road. Though, we thought the ride was a tad firmer and harsher than it needed to be in Sport Plus; stiff for the sake of stiff, not necessarily sharp, and not necessarily tuned for maximized grip.

The tires also had decent sidewall: 255/35/19 front and 275/35/19 rear Michelin Pilot Super Sports, with excellent grip and not much to note regarding noise. Thanks to the turbo I-6's 369 lb.-feet of torque on tap, they broke away easily-yet-predicatby when we wanted them to, and had excellent cornering grip.

The steering was very nicely weighted, albeit unsurprisingly did not transmit much in terms of feedback. Each mode had an appropriate amount of weight and tautness. The brakes are massive 13.7-inch front, 13.6-inch rear vented discs; they stopped very well and had very nice feel, although we didn’t get a chance to really push them.

A Ton Of Fun

We really enjoyed our week with the 2020 BMW Z4 M40i. Between its riot of an engine, great ergonomics, brilliant and luxurious interior, drop top, and great handling, we would say it’s a solid buy at $73,295. It’s engineered to check off the long-list of sensations that make convertibles a ton of fun, and we’re excited to see how this generation progresses. We hope to see them on track more as well, especially considering its sibling the Supra is getting all the track and aftermarket attention. Though, they’re marketed to pretty different demographics, by tune and by MSRP.

Check out our POV video!