Took the towing (i.e. withidl) plunge...

[Bayerische E53]

Originally Posted by JCL

I don't know of anyone who bought an F150 to tow. That is what F250s, F350s, and F450s are for.

Aero drag isn't safety related on terms of power of the 3.0. Crosswinds will be safety related but all models will be the same on that respect.

Tow limits are listed on the Euro BMW sites. Back in the day, when the E53 was current, there was an option called Increased Tow Capacity in Europe. It was a no charge option as I recall. I suspect it was a safety label calculated differently. I think it had a maximum grade percentage. The current E70 still has a similar option in Europe.

Do you have extensive towing experience? The driver will end up making most of the difference between safe and less safe.

One more issue is the insurance liability relating to exceeding manufacturer's ratings. Some worry about insurance being void. YMMV.

Good luck.

I see; thanks for the info. I would never hold myself out as a tractor trailer driver or even someone with years and hundreds of thousands of tow miles under my belt. That said, I am relatively new at towing, but I do have over 10,000 miles under my belt and I have towed with 5 different trucks and 3 different types of trailers. My maximum towing weight has been just under 6,000lbs - all without weight distribution. I've also driver several thousand miles in box trucks through cross-winds (monsoon conditions in the southeast, actually) for a fair bit of the time. Like I said, I'll never say I'm an expert, but I also wouldn't think that I'm merely an amateur, much less a newbie.

I have also always taken more precautions than the average person towing (In my opinion). I keep logs of wheel torques, tire pressures, miles travelled, fuel economy, trailer weight vs. tongue weight, etc. I think it's fair to assume that most people are not that anal every single time they trailer. But who am I to say...

Perhaps those who have significant towing experience could chime in and express their opinions. I'd be interested to hear their opinions. Of course, I am interested in your opinion as well, JCL, as I've seen that you've towed a fair bit albeit never exceeding about 5,000lbs (is that correct?).

Originally Posted by SlickGT1

I also have to mention that the trips home, with empty trailer and empty truck are way more wierd. It is like the truck need the weight in the back to feel more stable. And yes, I did not get the F150 to tow. I got it to be able to pack it full of crap and people and go on a job, and be able to park it in and around NYC. I am going for a shorter beast next time.

Very good points. I see your need for an F-150 is quite specific.

I'm not surprised that the truck towed a bit weird with an unloaded trailer. Trailers typically tow better the closer you load them to their maximum axle rating - the tongue weight proportioned to that total weight is also important. What happens is that the trailer tends to bounce around more and the tongue doesn't put enough pressure, let alone constant pressure on the hitch ball. Indeed, the pressure on the hitch ball tends to be more volatile because of the unloaded trailer's tendency to want to buck and up and down more than a loaded trailer. Simple physics, really. Great observation.

Originally Posted by TerminatorX5

S233A Increased towing capability

There you have it - it's merely a transmission duct for extra air cooling. That says everything - it's the transmission heat that limits the X5's towing capacity. Otherwise, it's good to 7,700lbs as JCL said. Just like the Porsche Cayenne. That seems to explain how I couldn't see how the X5's unibody could be that much weaker than the Cayenne's.

With the manual transmission, I'm sure I won't have to worry as there won't be a tendency for it to hunt for gears.

The other two things I found were that the increased towing capacity vehicles have different rear differentials - all the parts and ratio are the same, however, so I'm guessing it's maybe got a finned cooling cover on it. I also found that those vehicles also come with a 220A instead of 180A alternator. Thing is, the 220A comes on vehicles with 4-zone climate control, which my car has. So I'm good there too.

As for the diff, a little more heat just means replacing the fluid a bit more often. Big deal.

The E70 also seems to have a small additional engine radiator but I couldn't find this for the E53. Even still, on the highway, I don't see this being an issue.

I'll install the cooling duct for the trans anyways for safe measure. So it looks like I'm actually NOT overweight! That's very promising! Thanks for that!