35d Towing Impressions

[Mathme]

I picked up my Mineral White Metallic 35d in mid-July. I currently have about 3800 miles on it and have towed my boat & trailer approximately 800 of those miles. Since there’s a lot of discussion on here about towing, I’ve decided I’ll just write down some things I’ve found over my short time with the x5.

First though, here’s my build:
35d
M Sport with 19” wheels
Cold Weather
Driver Assistance
Lighting
Mocha Interior design
Premium Pkg
Comfort rear seats
Adaptive M suspension
HK Sound

The boat is a 23’ Yamaha jet boat with a tandem axle trailer. Fully loaded with 10 gallons of water and 50 gallons of dino juice and they weigh about 5300 pounds. Here’s what the rig looks like when it’s ready to roll…



Hitch
I use the Invisihitch with the active harness. In my opinion, this is the only way to go. Don’t bother paying your local dealer to install it as you can work with Darryl over at Invisihitch and get better prices. My install cost was $350 in the bay area.

Here are some pics of how the set up looks:
Connection points (left is lights, Right is hitch)


Close-up, equal with the bottom of the rear bumper


From a higher perspective…you can’t even see it


With the receiver attached


Wheels, 19 vs 20s
When I ordered the car, I had considerable internal debate between 19” or 20” wheels. After towing I’ve decided the 19” wheels are the way to go because you never quite know where you’ll be and what the surface you’ll be towing on will look like.

For example, while on a trip to Shasta, we ended up driving across about 2 miles of dry lakebed as the water level is down about 150’ from full flow. This ended up being a 1-lane road composed of shale and sand and looked like the following:

This is where the marina was last year. Note that all of Jones Valley is dry and the marina is out in the main Pitt River Channel now…



The 19” wheels and all season tires provided ample traction and no worries about rock punctures or scratches on the rims.

The “boat launch” was a one-lane ramp that required backing down about 200’ to the water. The boat is easy to back with the BMW. Picture the road above with more rocks on it basically heading into the lake…that’s your boat ramp. The iDrive display incidated the ramp was at about 16-18 degrees. When retrieving the boat, the rear wheels of the X5 were in the water and it was muddy down there. The X5 didn’t spin a wheel and the diesel just pulled the rig out without any sweat at about 1700-2000 rpm. I’m definitely glad I had all season tires on the car as I’m sure that mud down there would have been more of a challenge with summer tread.

Towing impressions
The diesel is a pulling machine - if you're going to tow, bypass the other two engine options and you won't be sorry. Overall fuel mileage from the Bay Area up to Redding was about 18 going up, and 15-16 coming back (into a strong headwind), this was with four people and a dog in the car. On the way back, outside temp was hovering a bit above 100F and the temp did climb on the gauge – but only about two needle widths – and nothing to be concerned about.

In California we are limited to a 55mph limit when towing, and when setting the cruise at about 61-62, she turns right at 1500rpm. Compared to my cayenne, there is no fuss or drama, it just goes about it’s business. Even in the headwind, the X5 was in 8th gear just pulling along. There was a little movement of the rig by the wind, but nothing that was a cause for concern as the X5 and trailer always felt planted and in control.

During the summer I keep the boat in a wet slip in Lake Tahoe and after Labor Day brought it down to the Bay Area. One thing to note with surge brakes is to put the transmission in Manual mode going down hill. There are so many gears in that transmission you don’t realize when it’s shifted down and it’s easy to drag the trailer brakes while coming down a hill on compression. This isn’t a deal-breaker, but it is something to note and be aware of. I’ve found that putting it in M and using the paddle shifters on the steering wheel helps control gearing much better. Once at the bottom of a hill, drop it back into drive and let the transmission take over.

Air Suspension
Definitely get the air suspension. The Adaptive M is worth every penny. There is a noticeable difference between Comfort and Sport when towing and depending on the road surface I toggle between the two quite often. With 500 pounds on the rear, there also isn’t any sag.

I have set my sport mode to only adjust suspension settings and not engine settings, and this is very helpful to stop the bounce on California’s notoriously not to smooth freeways. I find I toggle between the two settings fairly regularly.

Comfort Seats
There’s been considerable debate on the forum about the durability of the Napa Leather. In the time I’ve had it, it’s holding up quite well. We also have a 9-pound Terrier Mix who is always in the car and when getting out, she often jumps from the front to rear seat. There hasn’t been any scratches yet on that leather.

The Comfort seats took me about 1500 miles to dial in but now they are probably the most comfortable I’ve ever had in a car. My partner laughs about the seats and affectionately calls them “Business Class” with the build in head forming head rests.

I also have brushed aluminum trim with the Mocha. I also haven’t noticed any scratches in the aluminum as other users have mentioned. Here’s a few pics as some people like to ask what the combo looks like…

[ducatirdr]

Great write up. I am in the process of upgrading my E70 to the F15. My choice to go with the diesel is due to my towing a motorcycle toy hauler. The Livin' Lite 7x20 is ony 3700 empty and under 5000 fully loaded. Researching the hitch options brought me here. I think I will be using the Invisihitch. My gasser got 11mpg on the 2000+ mile trip to Daytona this past Bike Week. I'm looking forward to trading it in for the F15 M diesel which is coming next week.

[Jenya B]

Guys tell me please , do you install controller brake for trailer ??? if yes , how it looks ?

[00seven]

Great write up!
Thanks!
reminding me get my boat too

[ducatirdr]

Originally Posted by Jenya B

Guys tell me please , do you install controller brake for trailer ??? if yes , how it looks ?

I made the mistake of using the BMW controller. It's SUPER expensive and older technology. It's basically a Tekonsha Prodigy P2. Plus you lose a front cup holder where its install permanently. It works but its 10 year old technology.

The best system for a luxury vehicle is the Tenkonsha Prodigy RF wireless controller. It's use of wireless input to the trailer brake makes for simple installation as well as ease in swapping to any other vehicle later on.

Tekonsha Prodigy RF

[Jenya B]

i know about tekonsha , i'm interesting in bmw's solution for trailers with 2 axels and electric brakes.

[ducatirdr]

Originally Posted by Jenya B

i know about tekonsha , i'm interesting in bmw's solution for trailers with 2 axels and electric brakes.

The trailer I pull has 2 axles and electric brakes. I am using the BMW brake controller now in my E70 X5 as shown above in the photo above with the Harley. BMW's E70 brake controller is a repackaged Tekonsha Prodigy P2. I have it on my E70 now. There is no BMW brake controller for the F15 that I know of.

That said I will never use a hard wired brake controller again. I will use the Tekonsha Podigy RF on my F15 MSport 35d due to arrive next week. No fuss as there is no permanent installation to your vehicle. The brake controller transmitter simply pugs into your cig lighter when in use and feeds info to the electric brake controller on the trailers hitch frame through its RF. I will also be using the hitch and wiring from the Invisihitch shown in this post.

If you talk to Daryl at invisihitch he will recommend the same controller.
daryl@invisihitch.com

[NPickles]

Great write up. I've got an 1,600 mile towing trip from the UK to eastern Germany with a 12m dragon boat trailer which comes in at about 2 tonnes fully loaded which makes my rig longer than most trucks on the roads over here when towing.

I'm going to take it through the tunnel on the train which is an experience getting on and off, you get a few looks too mainly from the staff though you do get a whole full height carriage to yourself.

I have done it a couple of times before in my previous Lexus RX450h which did it okay but you had to stop for petrol what seemed like every few minutes as it killed the MPG so much. Hopefully my F15 40D will do an equally effortless job and require feeding and watering considerably less frequently than the RX did.

I'm going to see what the overall MPG is like and will report back in early April when I'm back. Only going to take a couple of days, 800 miles in a little over one day, no problem, but so glad I went with the comfort seats.

[ducatirdr]

Seems that the BMW's software to check tail light outage interferes with the Tekonsha Prodigy RF pairing process. The unit comes from the factory with a box that is the brake controller that mounts to the trailer hitch frame. The unit you put in the car tells the controller over RF what the setting for boost/intensity is. It also report if the controller is connected and report braking output.

This all works great once the in car unit is bound/paired to the controller black box on the trailer. The problem is that you can't pair the unit on an F15. The steps are you put the car unit in pairing mode and then press on the brake pedal till the unit shows 0.0. The BMW sends test signals to brake lights and that causes the controller to never pair.

What you need to do is to never mount the controller without pairing it first using a non-software lightbulb testing vehicle that most European luxury SUV's have. Yes that is Tekonsha's recommendation. I finally got around to setting mine up and found out today it won't pair. I went around the neighborhood looking for a neighbor with a truck wired with a 7-way trailer output and 12v power on pin one (This is a requirement for this trailer brake controller. Pin 1 is a 12v power to your camper for lights when plugged in) I was lucky to find a contractor with the right setup after testing a few other neighbors 7-way only to find they didn't serve the 12v... Once that contractors Chevy plugged into the controller we hit pair and pressed the brake and bingo it was working.

I plugged it then into my F15 and sure enough once paired it works fine.

Tekonsha should sell the unit already paired to the controller. Then it wouldn't be a problem.

[eefx]

Where did you purchase and install hitch in Bay Area? I picked up 16 X5M and have Centurion Enzo 24 boat to tow . Sold my 15 Tundra TRD pro and 13 G63 benz that i towed with .

Thanks !

Gene.

[BayAreaF16]

Very helpful post Mathme!! I am in the process of convincing my wife that we need a new SeaDoo, we will also need to install the Invisihitch! Looks like the way to go for sure!

[BayAreaF16]

Originally Posted by eefx

Where did you purchase and install hitch in Bay Area? I picked up 16 X5M and have Centurion Enzo 24 boat to tow . Sold my 15 Tundra TRD pro and 13 G63 benz that i towed with .

Thanks !

Gene.

Nice ride! Did you end up getting the Invisihitch installed on your X5M?

[UnhappySwede]

Nice boat! I was into the Yamahas back in the days when they made the dangerous, hard spinning, submoving 2-strokers. The newer ones look nice but I dont know how much of that agility is left. I did have a Seadoo Speedster aswell but it just wasnt as good...