Well, I can safely say it's "prepared-idiot-proof", at any rate.
Over the weekend, I drove from Los Angeles to Birmingham. I pulled a U-Haul 5x8 trailer.
I started with the Draw-Tite Class I hitch. I bought a Brophy 5.5" Rise Draw Bar, and a Convert-A-Ball 1 7/8" / 2" ball setup.
The 328 says I can load 1014 pounds of cargo in the car - so that's 260 pounds of me, 200 pounds of tongue weight, and about 550 pounds of stuff. Ok, cool.
The hitch is rated for 2000 pounds. A U-Haul 5x8 weighs about 900 lbs dry, so I loaded it up with about 1150 or so pounds of stuff. I made sure to load the trailer properly such that the weight distribution and tongue weight was correct.
To prepare, I flushed all the fluids in the car except brake fluid. I changed the oil (Molygen 5W40), new trans oil (Ravenol MTF3), new diff oil (Redline) and new 60/40 water/BMW coolant.
Before I left I reprogrammed the Kombi to show Oil Temperature. I also used Torque on my phone and an OBD2 dongle to get some additional telemetry.
Lastly, I swapped my performance rear springs back out for my stock standard suspension springs to get the (unloaded) ball height up. As you can see by the pictures this seemed to work out well - when fully loaded, the trailer tongue seemed perfectly level and the rear of the car was about as low as it sits with the performance springs and 4 people in the car.
So how did the drive go?
It went great. I whipped the car's ass for three days and 2100 miles and it never flinched.
Some fun data:
There was one singular incline that was more difficult than any other hill. Traveling east on I40, when you leave Albuquerque you go from about 5000 ft above sea level to 7200 feet above sea level. This hill was responsible for some of the highest recorded temperatures of the trip. Third gear, 4500 RPM WOT, for about five or seven minutes.
Maximum coolant temp the whole trip was 215 F for a brief period of time in uphill in California. Second highest coolant temp was going up The Hill east of Albuquerque, at about 212 F. The car seems to do an outstanding job of regulating the coolant temperature.
My gauge cluster has an MPG display so I couldn't get perfect values for oil temp, but the highest the gauge read was on the "15" on the MPG display, so I'm guessing that was about 135 C. This was the only time I began to worry. I kept a good eye on the oil temp and I was prepared to pull over, but it seemed to peak and never got above the 15 MPG tick.
Max O2 sensor temperatures were 1660 F, same stretch of road.
The BMW Performance Intake is outstanding. 103 F ambient temps, 108 F intake air temps. Intake temps were as low as 2 F above ambient.
I got about 15 MPG. I was hoping for 20. This was the only part of the journey I fudged on. I burned a shiiitload of gasoline. $500 worth.
This trip (and the extra telemetry) allowed me to make some fun automotive observations. The holy trinity of power: Altitude (air density), Temperature (air density), and Fuel Quality. When you're at 5000 feet and it's 95 degrees and you're running shitty west coast 91 octane fuel...well, let's say some boost would have been nice. The motor really had to work for its money under those conditions.
On the other hand - when I finally found my first 93 pump in Arkansas, the power jump was so immediate that I pulled over after leaving the gas station but before getting back on I40 because I thought my trailer door must have opened and my stuff fallen out. I guess I owe BPC a high five for that.
So can you tow with a 328? Yes.
Can you safely tow with a 328? Yes.
Will you get funny looks from dudes in Dodge Pickups pulling the same size trailer? Yes.
Will you get snooty looks from dudes in F30 3 serieses? Yes.
Was it fun? Yes.
Did I feel like a miniature long-haul trucker? Yes.
Was it cheaper than renting a 10' box truck? A resounding hell yes.
I've been in the car for three days so I'd love to discuss this with everyone.
