The F90 M5 has impressed users and critics alike with its awe-inspiring power, effortless delivery, and general embodiment of what BMW has always been about – refined performance. Form and function reign supreme from the factory in true German form. On the other hand, other aspects may not be as carefully cultivated. The stock exhaust note on the F90 M5 as an example, while no slouch, is probably best described as having a subdued aggressive note. Dinan believes for such a powerful and impressive car however that the vehicle deserves to be able to bellow a bit louder and more aggressively. The F90 M5 is the alpha on the public roads after all. Dinan’s goal is to let the machine sound the part in addition to performing it. With Dinan, there is no reason to sacrifice anything in the process to meet that goal either. Whether that be in the form of drone, civility, appearance or any other aspect. In order to achieve desired sound volume and tone, Dinan felt becoming of the F90 M5 the tubing was enlarged to 83mm (vs 80mm stock) to allow freer flow throughout the entirety of the system. The larger tubing is fed into a muffler that is typical of all Dinan exhaust design and utilizes absorption and reactive technologies designed to improve exhaust flow and reduce backpressure. The combination results in increased power output and a great sporty sound that is civilized when you want it to be, and pleasantly aggressive under hard acceleration. This is partly courtesy of the retained computer-controlled exhaust valves that limit noise during low-speed driving and open fully during high-load conditions to allow free flow and greater sound as the bulk of the gases are bypassing the muffler. Like all Dinan exhausts, our M5 free flow exhaust is engineered to reduce low-RPM drone so the cabin of the vehicle is still intimate and not drowned in an excessively loud tone. With the Dinan exhaust equipped on the M5 you get the best of both worlds; aggressive tone/sound and civility. A combination that we have termed internally as “refined aggression.” Sound isn’t the only aspect of the exhaust that has been modified. The Dinan F90 M5 exhaust has been skillfully crafted entirely out of T304 stainless steel and TIG welded for the best visual appearance and color. The entire system is then brush finished to further guarantee an immaculate looking system out of the box. The attention to detail is not limited to parts of the system you can’t see once the exhaust is installed but is also extended to the exhaust tips themselves. The Dinan exhaust sports enormous, quad 4″ (102mm) clamp-on, double-walled, black ceramic coated and laser engraved exhaust tips. Dinan has retained its signature straight-cut tip design, safeguarding its unique and elegant styling position amongst a crowded marketplace full of angle cuts. The tips masterfully fill up and accentuate upon the factory cut-outs showcasing an extremely aggressive, yet refined, styling that will turn heads even before it is heard.