[Expert@ApexWheels]

APEX Skunk Works: Pushing The Limits On The F31

Our BMW Product specialist, Max, recently acquired a 2015 F31 328d wagon to fill the role of his new daily driver. Since taking delivery of the car, the first thing on Max’s agenda was to install a fresh set of APEX wheels. Undecided as to what fitment he wanted to ultimately end up with, we figured it would be a perfect opportunity to test a few setups we had around the shop to see how aggressive you can really go on a completely stock X-drive F3X.

While we have plenty of confirmed direct-fit setups available for this chassis, such as the 18x8.5” ET35 square, we thought it would be worth sharing our findings for those who desire an even more aggressive square fitment for their F3X.

To read about some of our other fitments available for the F3X, feel free to check out our comprehensive chassis specific fitment guide located here.

TL;DR:

Test Fitment #1:
Front & Rear: 17x9" ET42 with 255/40-17 Toyo Proxes RR Tires
• 3mm front spacers required for stock suspension clearance. A larger spacer may be required for use with coilovers that are known to reduce inner suspension clearance.
• You may be able to get away with no spacers, but you'd need a very conservative tire. Stepping down to a 245 would make fitment easier, but still very close.

Test Fitment #2:
Front & Rear: 18x9.5" ET35 with 275/35-18 Toyo R888R Tires
• Not a recommended fitment
• 3mm front spacers required for stock suspension clearance. A larger spacer may be required for use with coilovers that are known to reduce inner suspension clearance.
• Although this combination bolted up and spun freely without spacers, there was less than 1mm of clearance to the front struts, and we do not recommend driving with clearance this small.
• At least -2º of front negative camber required.
• 255 street tires may work without camber adjustment, but not tested.

Test Fitment #3:
Front & Rear: 19x9" ET30 with 245/35-19 Michelin Pilot Sport 4S Tires
• Direct fit, no modifications required.

Test Fitment #4:
Front & Rear: 18x9" ET31 with 245/40ZR-18 Hankook Ventus S1 Tires
• Direct fit, no modifications required.

The Vehicle:

Make:
BMW

Model:
F31 328d X-Drive Wagon

Production Date:
2/15 (2015 Model Year)

Additional Notes:
Stock M-Sport suspension, OEM non-M performance brakes

The Test Equipment:

Wheels:
OEM: BMW Style 400M 18x8" ET34
Test fitment #1: APEX Forged ARC-8R Brushed Clear 17x9" ET42
Test fitment #2: APEX Forged EC-7R Brushed Clear 18x9.5" ET35
Test fitment #3: APEX Flow Formed SM-10 Anthracite 19x9" ET30
Test Fitment #4: APEX Flow Formed EC-7 Anthracite 18x9" ET31

Hardware:
Spacers: (For fine-tuning and clearance)
APEX 3mm spacer
APEX 5mm spacer
Extended lugs (for use with spacers)

Tires:
OEM: 225/45-18 Pirelli Cinturato P7 RFT
Overall diameter: 660mm

Test fitment #1: 255/40-17 Toyo Proxes RR
Overall diameter: 636mm

Test fitment #2: 275/35-18 Toyo R888R
Overall diameter: 650mm

Test fitment #3: 245/35-19 Michelin Pilot Sport 4S
Overall diameter: 654mm

Test fitment #4: 245/40ZR-18 Hankook Ventus S1
Overall diameter: 653mm

The Weigh-In:

For the sake of providing some additional data, we decided to pull out the scale to weigh-in each of our wheel and tire setups before mounting them on the car.



⬆︎OEM wheel and tire weight: 50.80 lbs⬆︎
BMW Style 400M 18x8" ET34
225/45-18 Pirelli Cinturato P7 RFT



⬆︎Test fitment #1 wheel and tire weight: 41.50 lbs⬆︎
Forged ARC-8R Brushed Clear 17x9" ET42
255/40-17 Toyo Proxes RR



⬆︎Test fitment #2 wheel and tire weight: 48.55 lbs⬆︎
Forged EC-7R Brushed Clear 18x9.5" ET35
275/35-18 Toyo R888R



⬆︎Test fitment #3 wheel and tire weight: 45.70 lbs⬆︎
Flow Formed SM-10 Anthracite 19x9" ET30
245/35-19 Michelin Pilot Sport 4S

Test fitment #4 wheel and tire weight: No weigh-in data collected
Flow Formed EC-7 Anthracite 18x9" ET31
245/40-18 Hankook Ventus S1

Test Fitment #1:

Wheels:
APEX Forged ARC-8R Brushed Clear 17x9" ET42

Tires:
255/40-17 Toyo Proxes RR

Hardware:
Front 3mm APEX spacers (suspension clearance)
Extended lugs (for use with spacers)



Fitment Notes:
With the aggressive 255/40-17 Toyo Proxes RR tires that were mounted on these wheels, this setup was not able to initially clear the front struts. In order to clear the front suspension components with these tires, a 3mm front spacer was required. However, even with a 3mm front spacer, the proximity between the strut and the tire was still very tight. If running an aggressive 255/40-17 tire on these wheels, a 5mm front spacer might be a better option for the sake of additional clearance.

The picture below shows the strut clearance with a 3mm spacer.



Stepping down to a more conservative tire size, such as a 245/45-17 could potentially allow for a spacer-less fitment, but the clearances will still be very tight.

The rear fitment with this setup sits a touch in-board of the rear fenders and is able to clear the inner suspension components just fine without the use of spacers.

Test Fitment #2:

Wheels:
APEX Forged EC-7R Brushed Clear 18x9.5" ET35

Tires:
275/35-18 Toyo R888R

Hardware:
Front 3mm APEX spacers (suspension clearance)
Extended lugs (for use with spacers)



Fitment Notes:
While this wheel and tire combination would typically be too aggressive for an F3X, we thought it would be worth testing to help show how a stock car would sit on an extra-wide track-focused setup.

We often receive requests from various F3X owners wanting to run the "widest and most aggressive fitment possible", but do not intend to modify any suspension components, alignment settings, or the fenders of their vehicle. Often times these requests will reference heavily modified vehicles equipped with fully adjustable coilovers, camber plates, rolled fenders, etc in order to run said aggressive track-focused fitment.

The goal of testing this particular fitment is to help show how it would not work on a stock car and to give those considering an aggressive setup a better idea as to what modifications they will need to install to support a similar fitment.



With the aggressive fitting 275/35-18 Toyo R888R tires, the fronts were able to bolt on and spin freely without spacers. However, we would not recommend driving a car like this, as the tire sat just 1mm away from the front strut. With the addition of 3mm front spacers, suspension clearance was still quite close, but driveable nonetheless. When using 275/35-18 tires and 3mm front spacers with this setup, a minimum -2 degrees of camber would be required to alleviate rubbing on the front fender. For the rear, a minimum of -1.7 degrees and a slight fender roll would be required to alleviate rubbing on the rear fender.

If someone was interested in running a setup like this, it could possibly work with aggressive negative camber specifications both front and rear. However, a 265/35-18 or even a 255/35-18 tire would be better suited for a 9.5” wheel, and would provide a more ideal overall fitment with less aggressive tire “shoulders” compared to the 275/35-18 R888R.

The picture on the left shows the clearance without a spacer, while the picture on the right shows the clearance with a 3mm spacer.

Test Fitment #3:

Wheels:
APEX Flow Formed SM-10 Anthracite 19x9" ET30

Tires:
245/35-19 Michelin Pilot Sport 4S

Hardware:
N/A



Fitment Notes:
As one of the more street-oriented setups we tested, the 19x9" ET30 with 245/35-19 Michelin PS4S tires offered a direct fit without any additional modifications or hardware required.

The SM-10 wheels provided a flush fitment while still maintaining plenty of clearance for both the inner suspension components and the fenders. During our testing, no rubbing was observed on the OEM M-Sport suspension-equipped wagon.

The 245/35-19 Michelin PS4S' tires were an ideal fit, as the 9" wide wheels offered plenty of sidewall support for that particular tire size. A 255/30-19 tire could also be used, but we would recommend dialing in a touch of front and rear negative camber to help alleviate any rubbing that might occur under compression.

Test Fitment #4:

Wheels:
APEX Flow Formed EC-7 Anthracite 18x9" ET31

Tires:
245/40ZR-18 Hankook Ventus S1

Hardware:
H&R Sport lowering springs



Fitment Notes:
Much like test fitment #3, this setup offers a direct fit without any additional modifications or hardware required. The 18x9" ET31 square setup can be quite versatile, as it provides an ideal balance of performance without being too aggressive for a street driven car.

With the 245/40-18 Hankook Ventus S1 all-season tires, this particular setup is more dialed-in for daily street driving. However, with a 255/35-18 in a more performance-focused tire compound and a touch of front negative camber, the 18x9" ET31 square setup can be a solid option for track use.

The 18x9" ET31 EC-7 wheels can work on an F3X with stock suspension but benefit significantly from a slight drop in ride height. Compared to test fitment #3 on OEM M-Sport suspension, the addition of a set of H&R lowering springs helps dial-in a flush fitment front and rear.

[ECTO1]

I know nobody has said it but awesome write up.

[Stlblues]

Agreed! Much appreciated!

[FaRKle!]

Great info. I wish I had gone with 18x9 instead of 18x8.5 SM-10s I got for my F31 for the track. Got a trade-up program? Haha