Toyota and BMW partnering up for a sports car is perhaps one of the most unlikely pairings in the automotive industry. One is a manufacturer of cars for the masses, while the other caters to the sport-luxury crowd. The result, as we all know, is the Toyota Supra and BMW Z4.

It's easy to be dismissive to both cars (if you can afford to be dismissive about them) that one is a hardtop version of the other and vice versa. But just how similar, or different, are they upon looking at the spec sheets and first impressions? We've sat in them both, and run the numbers on each.

Same-same but very different: Toyota Supra versus BMW Z4 image

Tale of the tape

Given that both these cars ride on the same architecture, you expect them to have the same dimensions. In some ways, you'd be correct. While they're not exactly the same, there's a few millimeters in between them.

In terms of length, the Supra edges out its drop-top cousin ever so slightly with the Toyota measuring in at 4,378 mm. The Z4 on the other hand is 4,324 mm long. On the flipside, the BMW is wider and taller than the Toyota. Width and height for the Z4 is at 1,864 mm and 1,304 mm, respectively. The Supra meanwhile is 1,853 mm wide and 1,292 mm tall. That is actually rather surprising since the Supra is a hardtop. Perhaps the BMW rides a little higher off the ground compared to the Toyota? Not even. In fact, the Supra is higher off the ground than the Z4 at 115 mm, and the difference is a very negligible 1 mm.

Where the two are the same is in wheelbase, both at 2,470 mm.

Same-same but very different: Toyota Supra versus BMW Z4 image

Tipping the scales

They have identical dimensions, but there's a big difference between the two when it comes to weight. Mind you, neither of these cars are what you'd call flyweights. At 1,520 kg, the Supra is a significant 90 kilograms lighter than the Z4. The BMW tips the scales at a portly 1,620 kg. So why is the Z4 that much heavier than the Supra?

The answer lies in each of their body styles. Coupes are inherently more rigid than convertibles from the start. That's not to say the Z4 has the structural integrity of overcooked pasta. To make a roadster just as solid as a hardtop, it needs more reinforcement, cross members, and beams to make it stiffer. Putting all those in adds weight, explaining why the Z4 has to lug around a lot more pounds.

Same-same but very different: Toyota Supra versus BMW Z4 image

What's inside?

The two may be the same under the skin but it's a totally different matter when you get on board. Instead of just slapping their respective badges inside, BMW and Toyota made an effort to make their interiors just as dramatically different as their exterior. This is no BR-Z/86 job and we greatly appreciate the two for that.

In the BMW, it has a more 'organic' interior design with swooping lines, curves, and geometric shapes throughout the cabin. Instead of the typical 'floating' infotainment screen, this one actually has it integrated into the dash. There's also the signature BMW center stack which is tilted towards the driver. As for the Toyota, it adapts a more tradition, even slightly retro, design with its flat top dash and slim dashboard fascia. Even the infotainment screen placement is different, along with the air-conditioning vents and instrument cluster.

However, if you know your BMWs, you might spot some bits in the Supra that came from Munich's parts bin. There's the gear selector, the buttons for the drive modes, climate control interface, and radio buttons. It even has the BMW iDrive scroll wheel and the headlight switches appear very similar. Also, the Supra's warning chimes may sound familiar to BMW owners who have models from 2010 up until last year. Still, having BMW interior bits doesn't sound so bad, right?

Same-same but very different: Toyota Supra versus BMW Z4 image

Under the hood

This is where the two are exactly the same. Both use BMW's TwinPower Turbo 3.0-liter inline-six engine. Both put out 340 PS (335 Hp), 500 Nm of torque, and shift via an eight-speed automatic transmission. Curiously the US-spec Z4 has more power than the one we get here despite using the same engine. Over there, they get 387 PS from boosted straight-six mill.

Back to the local setting, you get two engine options for the BMW while Toyota only offers one, not that we're complaining. The Z4 has a turbocharged four-cylinder option here which makes 197 PS and 320 Nm of torque. So why doesn't the Supra come with this option? Let's be frank here; would you consider buying a Supra that makes about the same power as an 86? For that, we're glad Toyota brought in just one engine spec.

Same-same but very different: Toyota Supra versus BMW Z4 image

How fast?

They make the same power and use the same transmission. Acceleration figures should be the same, right?

That's not the case here at all. It's not that one is significantly faster than the other, but there is quite a gap when they both peel off to do a 0 to 100 km/h sprint. With that, it's the Supra that's faster than the Z4, at least based on their respective factory claims. The Toyota can get to 100 km/h from a standstill in 4.3 seconds, while the BMW does the same task in 4.6 seconds. Some of you might say that three tenths of a second isn't that much, but that's still a good car length away when they get off the line.

Same-same but very different: Toyota Supra versus BMW Z4 image

Head to head

What have we learned so far? They may be the similar in many ways according to their spec sheets, but you can't really dismiss them for being the same car under the skin. The BMW for instance is heavier and wider than the Toyota, while the latter is longer, lighter, and faster on paper. There's only so much numbers can tell, and the best way to know the differences is to drive them. One thing is for sure, we'd love to drive the two back to back.

So, Supra vs. Z4 anyone?