What do I Need for My 2021 BMW X3 M40i so I Can Tow a 6x12 Trailer to Move to a Different State?

Updated 07/31/2025 | Published 07/26/2025

Products Featured in This Question

Stealth Hitches Hidden Rack Receiver - Custom Fit - 2"

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$638.00

No-Drill Mount Bracket, Long

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$19.75

Draw-Tite Max-Frame Trailer Hitch Receiver - Custom Fit - Class III - 2"

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$222.14

Curt Mounting Bracket for 4-Pole Flat Trailer Connector

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$5.94

etrailer Ball Mount w/ Pre-Torqued 2" Ball - 2" Hitch - 2" Drop - 7,500 lbs

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$43.91

Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires

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$121.25

Redarc Tow-Pro Liberty Brake Controller w/ Universal Wiring Harness - Dash Knob - Proportional

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T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

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$98.92

Question:

Hello, I am looking for a trailer hitch that can tow a 6x12 trailer for relocating to a different state. Heavy duty enough to fit a small studio apartment. 2021 bmw x3 m40i

asked by: Michael R

Expert Reply:

Hello Michael,

Happy to get the right tow package together for your move to a different state. I would like to mention that just because the hitch is rated for a specific weight does not mean your car can tow that much, you will need to check your owners manual to see what BMW says you can tow, you are only as strong as your weakest link.

The highest rated hitch we for your 2021 BMW X3 M40i is the Draw-Tite Max-Frame Trailer Hitch Receiver - Custom Fit - Class III - 2" # 76226.

For a ball mount I would go with our etrailer Ball Mount w/ Pre-Torqued 2" Ball - 2" Hitch - 2" Drop - 7,500 lbs # e67DR

For wiring you will want the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # TK77FR, this wiring is going to get a 4 flat on the rear to control the lights. For a clean, finished look, be sure to add a # 18136 mounting bracket and the # C42CR no-drill bracket.

If the trailer you will be towing has brakes you will need to build on top of the # TK77FR by installing the Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires # ETBC7. The # ETBC7 is a little more difficult of an install as you will need to run a power line from the battery to the rear of the vehicle with a couple of amps along the way, as well as a brake wire from the front to the 7 way on the rear.

If you are pulling a trailer with brakes, you will also need a brake controller, the Redarc Tow-Pro Liberty Brake Controller w/ Universal Wiring Harness - Dash Knob - Proportional # RED52VR.

If you are getting it from Uhaul you will just need the 4 flat wiring as they use a surge brake actuator to control the brakes. Where are you getting the trailer from? Are you moving for work, or just ready for a new adventure?

expert reply by: Kate F

Michael R.

7/30/2025

Hello, Thank you for the information. I will be getting the trailer from U-Haul. Either it will be a 6x12. Or something smaller. I may sell some stuff, so I might be able to get something smaller than a 6x12.

Kate F.

7/30/2025

@MichaelR Perfect Michael, you don't need to worry about the 7 way and the brake controller. Hope you have a stress free move =)

Michael R.

7/30/2025

@KateF Katie, So I just need the hitch and the ball? No wiring? Do they supply that?

Kate F.

7/31/2025

@MichaelR You will need the 4 flat wiring to control the lights on the trailer. Here is what you will want to get: # 76226, # # TK77FR (For a clean, finished look, be sure to add a # 18136 mounting bracket and the # C42CR no-drill bracket), and for the ball mount I am going to change it. The U-Haul couplers sit a little tall at around 18", and your hitch when installed sits around 11", so you will need a rise. I would go with the # C45090, and for a ball # 63845. These items will have you ready to hook up to a U-Haul =)