A little sibling rivalry here. It's time to place your bets.

Out of all the BMW M models, the M5 Competition and M8 Competition are the most identical. Setting aside their body styles, the two M cars share the same engine and transmission, while having a minuscule weight difference at 33 pounds (15 kilograms).

But, their price difference is massive. There's around $20,000 price gap between the two, which begs the question – where does this money go?

To answer this, CarWow's latest drag race video is between the M5 Competition and M8 Competition. The spec sheet for both cars say that the M8 is quicker, but here's something to show you exactly why.

Gallery: 2019 BMW M5 Competition

First off, let's look at the numbers. Both cars are powered by a 4.4-liter twin-turbocharged and intercooled DOHC 32-valve V8 engine, with aluminum block and heads, as well as direct fuel injection. This engine is good for 617 horsepower (460 kiloWatts) and 553 pound-feet (750 Newton-meters) of pulling power.

Eerily, both cars have the same 8-speed transmission, too, and the same M xDrive all-wheel-drive system. The main difference is that one's a sedan that could seat up to five, while the other's a coupe that could barely seat a human being at the back.

As it turns out, there's another deviation between the two that the CarWow's video will show you. There's a clear winner in this drag race, and you can see that by clicking the play button on the video on top of this page.

And yes, that's where your 20 grand would be spent if ever you'd go for the M8 Competition instead of the M5.