Before we dig into our plans to improve the M5’s oil cooler, let’s take a look at the OEM cooler. BMW engineers are masters of packaging. Effective use of space is the name of the game, and when it comes to fitting the array of coolers on the front of their powerhouse sedans. In the case of the oil cooler, the engineers mounted this heat exchanger horizontal and right at the edge of the M5’s big-mouthed fascia and perpendicular with the rest of the cooling stack. This mounting method means that the cooler effectively utilizes the vehicle’s aerodynamics to maintain proper oil temperatures in this location. 

This oil cooler mounting method is also found on the F8X M3/M4 and follows the same concept. Essentially, the undertray creates a low-pressure zone behind the underside of the cooler. Basic laws of physics determine that high pressure wants to move to low-pressure zones, which draws some of the airflow from the front of the car—the downside to this method – parking barriers.

Even with the extra comfort-oriented amenities equipped to the M5 and M6, they are still low-slung GT sports sedans at heart and are designed to hug the pavement, even more so if you’ve lowered your M5, too. This concept enhances the daily driving experience, but it also puts your oil cooler directly in harm’s way. So, you have two options. You could give your M5 or M6 the proper safari treatment with a lift and body armor or just strengthen your oil cooler. We’ve already got the ball rolling on the rugged oil cooler option. 

Our oil cooler plan has two primary prongs. The first and most important is making sure that it can shrug off direct hits from parking barriers, curbs, road debris, or anything else that would cause your oil cooler to spring a leak. The second is maximizing the cooling potential. Luckily, most of our plans already combine these two goals.

First on the list is a more robust core. Tube-and-fin style heat exchangers are ideal for weight savings along with production costs, but there’s a better option out there. Instead, we plan to enlist the use of bar-and-plate core construction. Not only will this style of the core be better suited to glance incoming obstructions, but the heavy-duty bars and plates are more conducive to transferring heat. 

The core’s construction isn’t the only revision that we plan on making, and we are also opting to fill out some of the space we have available to us by adding to the core’s thickness. Adding more core volume in conjunction with the more robust core construction is the basic formula for improved cooling, which is now destined for our M5.

Since our new core design outgrew the OEM specifications, our engineer, Dan, needed to further solidify the oil cooler with a new pair of end tanks. Where the BMW design featured stamped aluminum tanks, we’re plotting on even tougher CNC-machined billet aluminum end tanks that will be securely fastened to the core via expert TIG-welding.

Executive decisions might only take a few seconds to declare, but in most cases, the proper implementation of those actions can take much longer. In the case of our M5 oil cooler defense strategy, even with the plans in place, the strengthening needs to be implemented appropriately. So make sure that you stay tuned for the first look at our new oil cooler coming soon!

When we last left off, our F1X/F9X oil cooler went from a digital design to a physical manifestation of this model. We used this fabricated framework to triple-check the fitment before kicking off full-scale production. Our first oil coolers are in, and we’re eager to show them off. 

Our new design started with the core. We wanted to make sure this new cooler was tough enough to shrug off any potential road hazards or parking barriers while properly keeping oil temperatures in check. So, we swapped out the flimsy tube-and-fin core replacing it with a much more robust bar-and-plate design. This core construction uses more heavy-duty fins and fluid passages, making it tougher than its tube-and-fin counterpart. To further protect the S63’s lifeblood, we also updated the end tanks on this cooler from thin stamped steel to a much more solid CNC-machined billet aluminum design.

Strength is only one component of our new oil cooler design, and we wanted to make sure that this new heat exchanger lives up to the class of vehicle it’s designed to fit. To do this, we started with expanding our core’s thickness by 10mm, which increased the system’s fluid capacity, plus a 24% bump in core volume. Our engineer, Dan, also made sure to pack even more fins into this cooler resulting in a 40% increase in external fin surface area. Combined, these characteristics are ideal for improving heat dissipation characteristics for maintaining proper oil temperatures. 

A revised oil cooler is just what the F1X and F9X platforms needed to get a leg up over the fierce competition. Better oil temperature management and a robust core turn this vehicle’s greatest weakness into a valuable asset and poised for the chief executive sports sedan position. Want to help your M5 or M6 succeed? Grab a Mishimoto oil cooler today: 

Performance Oil Cooler, fits BMW M5/M6, 2012+