Aftermarket tuning offers a lot of things to the owner of a car. Personalization is oftentimes the reason for car owners to tune their cars, with substantial aesthetic upgrades that sometimes enhance the performance of the car. Some even go as much as decorating their cars with Swarovski crystals because, really, why not?

Other tuners, however, focus on performance. By adding extra horses and pulling power to the engine, these tuned cars promise more fun driving experience and race-winning run times. But really, how much of a difference that extra power really add?

Gallery: 2018 BMW M5 Competition

To demonstrate this, Top Gear pit two BMW M5s in a drag race. But this is not ordinary M5s. The first M5 is an M5 Competition package, which is a slightly beefed up version of the already exhilarating M5. The other M5 is a tuned version of it by DMS.

For the uninitiated, the M5 Competition is powered by a 4.4-litre S63 twin-turbo V8 that produces a whopping 616 bhp and 553 lb-ft of torque. Its 0-62 miles per hour acceleration rate is at 3.3 seconds. Not too shabby for a car with four doors and weight of 1,865 kilograms, right?

The BMW M5 DMS, on the other hand, uses the same engine, albeit, tuned to produce more power – 774 bhp and 649 lb-ft torque to be exact. Interestingly, it's lighter by 10 kg. Even better, you'll only have to pay £2,795 more to get this pumped up M5.

With these differences laid out, does the 158-bhp gap matter in a quarter mile drag race? Watch the video on top of this page to find out.

Source: Top Gear via Youtube