BMW M5 E60 Exhaust Review: MagnaFlow S85 V10 Cat-Back

The E60 BMW M5 is the only production sedan ever fitted with a naturally aspirated V10, and its 5.0L S85 engine still sounds like nothing else on the road. The right BMW M5 E60 exhaust unlocks that voice without touching the tune — and the MagnaFlow Touring Series #16859 cat-back is the one bolt-on cat-back system built specifically for the 2006–2010 M5. In our Tampa, FL shop it is the most-requested upgrade for S85 owners who want more character and a lighter, free-flowing exhaust while keeping the factory catalytic converters in place. This is our full review: specs, sound, fitment, and where it fits in a complete build.

What Makes the E60 M5's S85 V10 So Special?

The 2006–2010 BMW M5 (E60) is powered by the S85B50, a 5.0L (4,999 cc) naturally aspirated 90-degree V10 that produces 500 horsepower at 7,750 rpm and 383 lb-ft of torque at 6,100 rpm. It revs to an 8,250 rpm redline — Formula 1-inspired territory for a road car — and breathes through ten individual throttle bodies. Paired with the 7-speed SMG III (or the later 6-speed manual), the E60 M5 hits 60 mph in roughly 4.1–4.5 seconds.

That engine is the whole point of the car, which is exactly why the exhaust matters. The factory system is heavy and deliberately muted, muffling one of the best-sounding production engines BMW ever built. A quality cat-back lets the S85 sing through the upper rev range while shedding weight over the rear axle — without altering emissions hardware or requiring a retune. With just over 20,000 E60 M5s built worldwide and values climbing as clean examples get harder to find, owners increasingly treat the car as a modern classic worth investing in — and a name-brand, warranty-backed exhaust is exactly the kind of reversible, high-impact upgrade that suits it.

MagnaFlow Touring Series #16859 Cat-Back: Reviewed

The MagnaFlow #16859 is a crossmember-back (cat-back) system engineered specifically for the 5.0L S85 M5. It uses fast-flowing 2.5-inch mandrel-bent stainless-steel main piping and three Straight-Through mufflers that reduce backpressure versus the restrictive OEM setup, ending in a Quad Split Rear exit with four polished, welded double-wall, angle-cut, rolled-edge tips. MagnaFlow developed the system with extensive 3D scanning for a true direct-fit, and it is CNC robotically manufactured and backed by a limited lifetime construction warranty.

How Does the MagnaFlow #16859 Sound on the S85 V10?

MagnaFlow rates the #16859 at a Moderate exterior and Mild interior sound level. In practice, that means a noticeably deeper, more resonant V10 tone at wide-open throttle and a hardened wail as the S85 climbs toward its 8,250 rpm redline — while cruising manners stay civil enough for a daily driver. The three Straight-Through mufflers are tuned to eliminate the boomy in-cabin drone that plagues cheaper systems, so highway cruising at 75 mph remains conversation-friendly. It is louder and richer than stock, but not obnoxious — a deliberate "Moderate" tune rather than a track-only scream.

Fitment and Installation: What to Expect

The #16859 is a direct-fit, bolt-on cat-back for the 2006–2010 BMW M5 (E60) sedan with the 5.0L S85 V10. Because it is a cat-back (crossmember-back) design, it retains the factory catalytic converters, so it does not alter your emissions hardware — a Prop 65 warning applies, and you should always confirm local regulations. MagnaFlow's 3D-scanned tooling means the piping, hangers, and tips line up with factory mounting points, and most experienced DIYers can complete the swap on a lift or with a jack and stands in an afternoon. No tune is required: the S85's individual-throttle-body management adapts without a flash.

At NLP Performance we recommend replacing the exhaust hangers and slip-fit clamp hardware during install, and torqueing the tips to level them evenly in the rear valance for that factory-plus finish. Fitment covers all US E60 M5 model years (2006, 2007, 2008, 2009, and 2010).

MagnaFlow vs. the E60 M5 Bolt-On Menu

The cat-back is the headline upgrade, but S85 owners often stack it with a few complementary bolt-ons for sound, throttle response, and stance. Here is how the MagnaFlow exhaust compares to the other most popular in-stock E60 M5 upgrades, ordered as most owners tackle them:

Complete the E60 M5 Build

Pair the cat-back with these in-stock E60 M5 upgrades to round out sound, response, and stance:

Is the MagnaFlow #16859 Worth It for Your M5?

For most E60 M5 owners, yes. The MagnaFlow #16859 is the only cat-back exhaust engineered specifically for the S85 V10 M5 in our catalog, so it sidesteps the trial-and-error of adapting a universal system to one of BMW's most complex production engines. At $2,462 it sits at a flagship price point, but so does the car — and the return is a transformed exhaust note, reduced weight over the rear axle, and free-flowing 2.5-inch stainless piping that will outlast the vehicle thanks to its limited lifetime warranty. Compared with fabricated one-off systems, a 3D-scanned direct-fit removes fitment risk and keeps installation to an afternoon.

Where owners should temper expectations is peak power. As a cat-back on a naturally aspirated engine, gains at the wheels are measured in single-digit horsepower; the real payoff is sound, throttle character, and the emotional connection to that 8,250 rpm redline. If your goal is big dyno numbers, budget for headers and a tune on top. If your goal is to finally hear the S85 the way BMW's engineers heard it on the test bench — while keeping your catalytic converters and daily-driver manners — the MagnaFlow #16859 is the straightforward, warranty-backed answer.