mcnam1

I just bought a 2015 Q5 TDI and a 20.5' long ski boat with a dry weight of 2,880 lbs. Looking around online, it looks like the trailer is about 1,000 lbs (+/- 200 lbs).

As the Q5 is rated to tow 4,400 lbs, I'm likely close to the limit when you add gas, kids, cooler, etc. Trailer is a tandem axle and has surge brakes. So, is this OK /safe? Thoughts?

Also, any tips on driving with this tow weight? (besides slowing down and giving a lot of extra distance between cars, etc.) Like driving in manual to downshift, etc. Thanks!

Mrclopec

I don't have a comment regarding the safety of towing your specific setup, however I will say if you look on Audi UK's web site, the Q5 3.0 TDI has a tow rating of 2,400kg (5,291 lbs) on a 12% grade compared to the 4,400 lb rating for us in the states. Our limits are calculated differently than theirs but I am just pointing you toward that information to show that it CAN. Wether it SHOULD is another matter. Also, the Q5 is factory wired for a trailer brake controller in case you were curious.

mcnam1

Thanks. Should I switch from surge brakes to electronic?

MP4.2+6.0

I don't think there are "electronic" brakes. Electric, yes. Just a different way to apply them, and some adjustability. But, you can adjust the surge/slave cylinder too typically. Whatever you settle on, get to boat store for right wiring harness adapter if you don't have it. Audi factory starts from 7 round. Most boats are either basic 4 flat, or maybe 5. West Marine and other places have standard adapters.

See the prior reply for towing capacity in Europe. As in, higher. Keep in mind in Europe towing is often with "caravans"--trailers as we know them. As in way worse usually aero wise than a boat hull, and a boat is yet better aero wise if you use covers while towing. You have trailer brakes, which is the most obvious thing. Check their condition, has fluid been changed in recent years (if not new), etc. Likewise confirm wheel bearings/grease in good shape. No to one of your questions, don't downshift unless critical. In theory you are forcing surge brakes to work full time on the related descent since the slave cylinder is activated as it pushes into the hitch. I tow with disc rotor set ups on my trailer so less concern, but many boat trailers have old drum brake set ups more vulnerable to overheating.

You might want to get it weighed too. Trailer weight sounds a little high to me, If dual (tandem) axle as you say and lots of steel frame structure, maybe. I tow at 32-3500 pounds depending on fuel and gear load. In practice I'm towing with either the Q5 Hybrid or my W12. Either handles it easily, including pulls over the Sierras from near sea level up to 7200 feet at freeway (towing) speed. Have also towed extended distances at 100-105F in hilly environs. Q5 brakes combined w/ decent trailer brakes are up for it. Remember in Europe the brakes have to pull down from Autobahn speeds, so Euro vehicle brakes are typically relatively beefy for given vehicle class. You also have the incremental torque w/ a TDI, which I only have up to about 10 seconds in a Hybrid.

As a tip, make sure your trailer tongue is correctly balanced. Typical is 8-11% of overall weight IIRC, but not beyond hitch rating. As you get to heavier overall trailer weights, you often want/need to go to the lower end of the range to avoid overloading hitch/rear of vehicle. Yet more so if your tow vehicle has a conventional (non air) suspension, isn't HD for towing like a bigger pickup or domestic SUV, and/or you have vehicle more weighed down with people and luggage. Faulty tongue balance is the common cause of trailer sway, about the most dangerous common towing condition. I see it on the open road with other vehicles not infrequently. Owners often seem to ignore it or just think it's "normal"--not smart. I experience zero sway on my set up, and keep an eye out for it too. If you have a factory matched trailer and boat, hopefully it's right. Otherwise, or if you have added something heavy to one end of boat or other, you might want to check it. If you know how to do it, fine though not beginner stuff--move axle(s) as needed and can actually use a bath scale if you split load 50/50 using a 4x4 or something across two points (one to ground, one to scale). A lot easier to do with boat off the trailer if you know you want to tweak it some and bring along the tools--wrenches, sledge, wood block. Otherwise, have a boat shop check it (and overall weight) for you, along w/ any brake maintenance. Also, be sure to take your tire pressure up to max load capacity; basically what is on the door jamb sticker if you are running it lower otherwise.

Last, tow with boat gas tank low on fuel and fill only near destination before splashing if practical and you aren't using a full size type tow vehicle. I do that and then just burn fuel as needed and pull it back out with ¼ tank or less. At 45 gallons, that can affect my tow weight by 300 pounds; not insignificant. Also, know where your tank is relative to tongue balancing, and balance it for typical as towed weight distribution. On mine, tank is in floor pretty much right above axle area and has little affect on weight distribution front to back. If further forward like an I/O might be, it could affect it more.

brutus23079

I asked the dealer about this on my 2014 and they said it wasn't. They had to confirm with AoA. Dealer had no solution for me. Is this new for the 2015 Q5? If so, that's great. Means they heard my (and plenty others) bitching about not having an electric brake controller plug-in harness from the factory. I went with the wireless Tekonsha Prodigy P3 to avoid having to mess with (a.k.a. screw up) the Audi wiring.

mcnam1, +1 on get it weighed. I did on my travel trailer and had to remove the LP gas bottles and move the RV's battery to the back to get the tongue weight comfortably within spec. Still had 12% tongue weight after the adjustment, i.e. no sway. When you're towing up near the top, you gots to know where you stand (both in trailer weight and tongue weight). On surge vs electric brakes, I'll take either one as long as they're serviced, adjusted, and working properly.

Edit: I'll add a link (I'm sure there are many if you look) on using a regular bathroom scale to get tongue weight.
https://www.etrailer.com/faq-how-to-...ue-weight.aspx

Mrclopec

If you drop the lower instrument panel cover on the drivers side, In the area beneath the fuse panel there is a plug covered in foam. It has the Red/blue/white/black wire. It runs to the back of the trunk behind the right panel. There is then a plug there with the red and blue controller wires that tie into the factory trailer harness. Pretty slick. Here's a pic of my cargo area on the right side from when I was retrofitting rear seat heating. Look at the new control module I installed with the unwrapped harness. The foam plug with the red and blue wire is at its 1 o'clock. That red and blue along with a common and source run all of the way up to the drivers side.

Parsec

1) Please tell me you were joking about towing your kids
2) Tow ratings are extremely conservative in the US due to strict regulation. You can easily tow a 2900 lb boat. 100 gallons of fuel = 650 lbs which brings you to 3550 lbs. Try to find a trailer around 900 lbs and you should be good to go.

mcnam1

Ha! Whoops. I meant kids and stuff in the car - not in the boat.
Thanks again for all the info everyone.

brutus23079

Great info! Thanks for the info and pic. I'll take a look on my 2014. Figures the dealer (and their AoA contact) wouldn't know this existed...

Coolieman1220

As long as your tongue weight is right and the load is balanced, you should be fine. The audi tows well and the engine would be happier towing a load twice the weight of what the Q5 is rated for.