In 2001, the E46 M3 set the performance bar high, being only one of an elite few cars with over 300 bhp to boast a normally aspirated engine output north of 100 bhp/liter. Usually, this entails an engine capable of at least 8000 rpm—no easy feat in a street car, let alone one with such a long crankshaft.

At ec, we found two nearly identical E46 M3s we wanted to improve. Initially, the owners doubted getting any significant gains on such a high-strung engine, but we found some smile-inducing tricks.

Why two cars, you ask? We also wanted to answer for ourselves this question: Are two seemingly identical M3s really the same? See our sidebar for that answer.

Vehicle Data

Engine: S54 3.2-liter inline-six
Transmission: 6-speed SMG
Mileage: 84,500
Current Modifications: VMR V718 wheels, Continental ExtremeContact DW tires

Dyno Data

Dyno Type: Dynojet 424x
Transmission Test Gear: Third

Performance

Peak Power: 289.7 whp @ 7900 rpm
Peak Torque: 234 lb-ft @ 4800 rpm
35-95 MPH Dyno Acceleration: 4.95 sec.
7500-8000 RPM Air/Fuel Ratio: 12.7:1-11.9:1
Temperature: 71° F
Humidity: 12%

Test Notes

Our test facility was European Auto Source, which took out an entire Monday to assist us. As always, we made sure to maintain the same values for coolant, intake air and oil temperatures for consistency. All were monitored using EAS’ Autologic scanner, the equivalent to BMW’s own GT1 scanner.

EAS’ extra-high-powered fans made controlling fluid temps easy. Still, we took our time and, about 45 minutes and 15 dyno pulls later we had a baseline. For a rated “333 bhp” we were off to a very strong start.

General Maintenance

(Fluids, Spark Plugs)

Continental Tires and VMR Wheels

With the addition of only wheels and tires, the M3s were not only transformed visibly, but a significant performance gain was noticed as well.

VMR design its wheels to stay very true to the overall BMW look. The owner of Car 1 chose the split seven-spoke V710 wheel in matte black while Car 2’s owner went with VMR’s V718 split eight-spoke in gunmetal. EAS added the finishing touches with black-out kidney grilles.

Both wheels weigh an identical 25.5 pounds, the same as the factory 19-inch forged wheels they replace. While we stayed with the same as stock sized rear wheels at 9.5x19, we upped the fronts by a half-inch over stock to 8.5x19. For around $250-280 per wheel, VMR provides style and quality at a price that will save you thousands over other brands.

Continental ExtremeContact DW (Dry/Wet) max performance tires wrap the wheels with 235/35 up front and 275/30 in the rear, upping the front and rear by one and two sizes, respectively.

The ExtremeContact DWs feature an asymmetric design. It also features a “DW” indicator on the tread. Over time, as the tire wears, when only the “D” is visible, this tells the driver the remaining tread is safe on dry pavement only.

The German tire giant is no stranger to high-end performance. In fact, when tested independently by Tire Rack against other big-name brands—on a BMW 3 Series, no less— the Conti EC DW topped the list, being named the best in combined wet and dry performance, while also ranking the most comfortable and fuel efficient of the bunch.

Out of curiosity, we tried just two simple rips to 60 mph in a 15 minute window, comparing one of the M3’s original 255/35-19 tire setups against the Contis, and instantly found a tenth of a second gain at speeds starting as low as 10 mph. Additionally, while we didn’t get a chance to test it numerically, the overall braking and handling performance has significantly improved thanks to the larger sizes. Visually, the wider stance is thick icing on the cake.

At the end of the day, we ended up with two cars that are faster, handle better, brake better, have improved fuel efficiency and even look more menacing. Despite our setbacks with Car 1, this was a good day, and the owners are smiling.

Test 1

Performance

Peak Power: 294.2 whp @ 7900 rpm
Peak Torque: 234.9 lb-ft @ 4800 rpm
Max Power Gain: 6.8 whp @ 7600 rpm
Max Torque Gain: 4.7 lb-ft @ 7600 rpm
35-95 MPH Dyno Acceleration: 4.88 sec.
7500-8000 RPM Air/Fuel Ratio: 12.9:1-12.2:1
Parts: Redline manual transmission fluid, Redline gear oil, Liqui Moly synthetic 10w-60 motor oil and Mahle filter, Liqui Moly Engine Flush, Liqui Moly Motor Protect, magnetic drain plug; NGK Iridium DCPR8EIX spark plugs
Installation Time: 2 hours
MSRP: $225 total

Pros

Compromise-free upgrades available for most cars, prolonged engine life, easy install

Cons

None

Test Notes

I like to start with fresh fluids and plugs. Call this the new baseline if you will. Bavarian Autosport sells Liqui Moly and Redline products at the best prices. Ditto with Sparkplugs.com for almost all spark plugs.

Every time I’ve purchased a used car I’ve flushed out the entire system with these products and netted positive—and usually even greater—results on the dyno. But both cars already had this maintenance from the dealer within the last year.

Still, our choices proved better, and are some of the best bangs for your horsepower buck today. Additionally, with less drag to the wheels one could argue there’s improved fuel economy as well.

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