2018 Bmw M5 Competition – Maximizing Performance And Long-Term
The 2018 bmw m5 competition is a high-performance executive sedan that blends a 617-horsepower twin-turbo V8 with an advanced M xDrive system. This guide provides an in-depth look at its technical specifications, essential maintenance routines, and common troubleshooting tips to help you keep this machine in peak condition.
Owning a high-performance machine often feels like a full-time job, especially when you are balancing daily drivability with track-ready capabilities. You want a car that screams on the highway but remains composed during a grocery run, yet the complexity of modern German engineering can be intimidating for many owners.
I promise to break down the technical barriers of the 2018 bmw m5 competition, offering you clear, actionable advice on everything from oil changes to drivetrain settings. We will explore the nuances of the S63 engine, the shift from DCT to the ZF 8-speed transmission, and the specific maintenance items that prevent costly shop visits.
In the following sections, we will dive into the mechanical heart of the F90 generation, identify the “must-know” weak points for DIYers, and outline a performance-oriented service schedule. Whether you are a seasoned mechanic or a first-time M-car owner, this guide will serve as your technical roadmap.
The Engineering Marvel of the 2018 bmw m5 competition
The F90 generation marked a significant turning point for the M5 lineage, primarily due to the introduction of the M xDrive system. This was the first time an M5 sent power to all four wheels, solving the traction issues that plagued its predecessors while still allowing for a pure rear-wheel-drive mode.
Under the hood, you will find the 4.4-liter S63 twin-turbocharged V8, a powerhouse that delivers 617 horsepower and 553 lb-ft of torque in the Competition trim. This specific variant features a 7-horsepower bump over the standard model and a more aggressive suspension tune that lowers the ride height by seven millimeters.
The 2018 bmw m5 competition also benefits from stiffer engine mounts, which improve the connection between the drivetrain and the chassis. For the driver, this means more direct steering feedback and a more immediate response when you bury the throttle, though it does introduce a bit more vibration into the cabin.
Decoding the S63T4 Engine
The S63T4 engine utilizes cross-bank exhaust manifolds, which ensure that exhaust gas pulses reach the twin-scroll turbochargers at even intervals. This design minimizes turbo lag and provides a linear power delivery that feels more like a naturally aspirated engine than a traditional turbocharged unit.
High-pressure direct injection operates at up to 350 bar, ensuring precise fuel atomization for better combustion efficiency. If you are working on this engine, remember that the fuel system remains under extreme pressure even after the engine is turned off, so always follow proper depressurization steps before service.
The cooling system is equally complex, featuring two separate circuits: a high-temperature circuit for the engine and a low-temperature circuit for the indirect charge air cooling. Keeping these systems bled and free of air pockets is critical for maintaining consistent performance during spirited driving.
Maintaining the 2018 bmw m5 competition: A Technician’s Perspective
When it comes to maintenance, the 2018 bmw m5 competition requires a proactive approach rather than a reactive one. Because these engines operate at high temperatures and pressures, fluid integrity is the single most important factor in preventing premature wear on internal components.
While BMW suggests long oil change intervals, most experienced technicians recommend a 5,000-mile or 6-month interval using a high-quality LL-01 FE certified synthetic oil. This helps protect the rod bearings and turbocharger seals, which are notoriously sensitive to oil breakdown and carbon buildup over time.
Brake maintenance is another area where costs can skyrocket if ignored, especially if your car is equipped with the optional Carbon Ceramic Brakes. While these offer incredible fade resistance, the rotors are exceptionally expensive to replace, so monitoring pad thickness is a non-negotiable task for any owner.
The Critical Oil Change Procedure
To perform a DIY oil change, you will need approximately 10 liters of 0W-30 or 5W-30 synthetic oil and a fresh filter kit. Always replace the crush washer on the drain plug to prevent slow leaks that can develop under the high pressure of the M5’s oiling system.
Accessing the oil filter requires removing the underbody shielding, which is held in place by several 8mm and 10mm bolts. Take this opportunity to inspect the turbocharger coolant lines for any signs of “crusty” white residue, which indicates a slow leak that needs immediate attention.
After filling the engine, use the iDrive system to check the oil level, as there is no traditional dipstick. Ensure the car is on level ground and at operating temperature to get an accurate reading; overfilling can be just as damaging as underfilling due to potential crankshaft aeration.
Spark Plug and Ignition Coil Service
The S63 engine is hard on spark plugs, especially if you have installed a performance tune. I recommend replacing the plugs every 20,000 to 30,000 miles to ensure optimal combustion and to prevent misfires that can trigger a “Drivetrain Malfunction” warning on your dash.
Use only the OEM-recommended High Power spark plugs and ensure they are gapped correctly to 0.028 inches (or tighter if running high boost). When pulling the ignition coils, inspect the boots for any signs of oil fouling, which usually points to a leaking valve cover gasket.
Torque the spark plugs to 23 Nm (approximately 17 ft-lbs) to ensure a proper seal without stripping the threads in the aluminum cylinder head. Always use a thin-walled 14mm 12-point spark plug socket, as a standard deep socket may get stuck in the narrow spark plug wells.
The M xDrive and Transmission Care
The transition to the ZF 8-speed automatic transmission in the 2018 bmw m5 competition was a departure from the dual-clutch (DCT) units of old. This transmission is incredibly robust and can handle massive amounts of torque, but it still requires fluid services despite BMW’s “lifetime fill” claims.
For those who drive their cars hard or visit the track, a transmission fluid and filter (pan) swap every 50,000 miles is a wise investment. The ZF 8HP is sensitive to fluid levels, so the refill procedure must be done at a specific temperature range (typically 30°C to 50°C) while the engine is running.
The M xDrive transfer case is another component that benefits from fresh fluid. If you notice a “shudder” or “binding” sensation during tight low-speed turns, the transfer case fluid may be sheared and in need of a replacement with the specific BMW DTF 1 lubricant.
Managing the Differential Fluids
The M5 uses an Active M Differential at the rear, which utilizes an electric motor to vary the locking effect between the wheels. This unit requires a specific SAF-2200 fluid that handles the high shear forces generated during aggressive cornering and launches.
The front differential is much smaller and holds less than a liter of fluid, making it easy to overlook. However, because it sits close to the hot exhaust manifold, the fluid can degrade faster than expected, so I recommend changing it whenever you service the transfer case.
When draining these fluids, always remove the fill plug first. There is nothing worse than draining your differential only to realize the fill plug is seized, leaving your car stranded on the lift without a way to replenish the lubricant.
Addressing Common Problems and Pitfalls
Every high-performance car has its quirks, and the 2018 bmw m5 competition is no exception. One of the most documented issues is the coolant expansion tank, which is prone to developing hairline cracks or leaking at the seams over time.
If the tank leaks, coolant can drip directly onto the fuel injectors and ignition coils located below it, leading to electrical shorts and expensive repairs. Many owners choose to replace the tank preventatively every 30,000 miles or install a protective shield to divert any potential leaks away from the engine electronics.
Another common concern involves the low-pressure fuel sensor. If this sensor fails, you may experience long crank times or a sudden loss of power; fortunately, it is a relatively simple DIY fix located on the fuel line near the firewall on the driver’s side.
Suspension and Tire Wear
The Competition model features increased negative camber at the front axle to improve turn-in grip. While this makes the car handle like a dream, it also leads to accelerated wear on the inner edges of the front tires, especially if the toe alignment is not perfectly dialed in.
Check your bushings, specifically the thrust arm bushings, for any signs of cracking or fluid leakage (as they are hydro-filled). Worn bushings will cause steering wheel shimmy under braking and can ruin a fresh set of Michelin Pilot Sport 4S tires in just a few thousand miles.
If you hear a “clunking” sound over small bumps, inspect the sway bar end links. The 2018 bmw m5 competition uses stiff anti-roll bars that put a lot of stress on these small ball joints, and they are often the first suspension component to fail on rougher roads.
Performance Modifications for the F90 M5
The S63 engine has massive headroom for power, and many owners of the 2018 bmw m5 competition look to unlock even more performance. A simple “Stage 1” ECU flash can easily push the car past 700 horsepower without needing any physical hardware changes.
However, once you start increasing boost, the charge pipes become a potential failure point. The factory plastic pipes can crack under high pressure, so upgrading to aluminum or silicone charge pipes is a smart “supporting mod” to ensure reliability under load.
Exhaust modifications are also popular, as the factory particulate filters (in some regions) and heavy mufflers can mute the V8’s natural growl. A set of high-flow downpipes will not only improve the sound but also reduce backpressure, allowing the turbos to spool significantly faster.
Wheel and Tire Considerations
The stock 20-inch wheels are beautiful but heavy. Switching to a lightweight forged wheel can reduce unsprung weight, which directly improves suspension response and acceleration. Stick to the 5×112 bolt pattern and pay close attention to the offset to avoid rubbing on the fenders.
For tires, the Michelin Pilot Sport 4S is the gold standard for this platform, offering a perfect balance of wet and dry grip. If you plan on frequent track days, consider the Cup 2 tires, but be aware that they require heat to work effectively and wear much faster on the street.
Always use a calibrated torque wrench when installing wheels, tightening the bolts to 140 Nm (103 ft-lbs). Using an impact gun without a torque sticks can lead to warped brake rotors or snapped wheel bolts, which is a headache you definitely want to avoid.
Frequently Asked Questions About 2018 bmw m5 competition
Is the 2018 M5 Competition reliable enough for a daily driver?
Yes, the F90 platform has proven to be remarkably reliable compared to previous generations like the E60 or F10. As long as you stay on top of oil changes and address the coolant tank issue preventatively, it can easily handle daily commuting duties.
Does the 2018 model have the same rod bearing issues as older M5s?
The S63T4 engine in the 2018 bmw m5 competition does not suffer from the same chronic rod bearing failures seen in the S65 or S85 engines. However, using the correct oil and avoiding high-load situations until the engine is fully warm is still essential for long-term health.
Can I turn off the All-Wheel Drive system?
Absolutely. The M xDrive system allows you to select a 2WD mode, which disconnects the front axle entirely. This mode also requires you to turn off Dynamic Stability Control (DSC), so it should only be used by experienced drivers in controlled environments like a race track.
What is the most important DIY tool for this car?
A high-quality OBDII diagnostic scanner (like BimmerLink or an ISTA+ setup) is vital. Because the car is so heavily computerized, being able to read manufacturer-specific codes and register a new battery or reset service lights will save you thousands in dealership labor costs.
Final Thoughts on the F90 M5 Competition
The 2018 bmw m5 competition remains one of the most capable “do-it-all” cars ever produced. It offers the luxury of a 7-series with the soul of a supercar, provided you are willing to give it the specialized care it deserves. By following a strict maintenance schedule and keeping an eye on known weak points, you can enjoy this 617-hp beast for years to come.
Remember that safety is paramount when working on a vehicle of this caliber. Always use high-quality jack stands, wear eye protection when dealing with pressurized fluids, and never hesitate to consult a professional technician if a job feels beyond your current skill level. Staying proactive is the key to M-car bliss.
Stay safe, keep the shiny side up, and enjoy the drive!
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