2015 Yukon SLT Towing

[cfendya]

Hey guys, I'm new here and recently picked up a 2015 Yukon SLT. I've read all the great reviews on the new engine/transmission and I'm currently trying to figure out a safe and acceptable towing capacity as we're looking to pickup a travel trailer for camping!

I've seen conflicting info out there hence my questions. Does anyone know what the non-HD trailer package Yukon can tow? The manual states 6300 w/ 3.08 gears but I've seen higher numbers than this. I do know our Yukon came with the oil and transmission cooler so the only thing we're missing from the HD towing package is the 3.48 and brake controller. The hitch says max of 10k with a max tongue weight of 1k.

We're looking at a trailer that weighs 5200 minus water and I'm figuring another 500 or so pounds loaded with our stuff. That would put us pretty close to the max so curious what the thoughts are in maxing out tow capacity.

One final note...We're at high altitude residing in Denver, CO. Folks have told us the high altitude will come into play when towing anything.

Thanks in advance for any thoughts and guidance. Anyone that has a '15 and tows that can weigh in would be a huge help!!

 

[malones99]

I would go with what the manual states, however a 4x4 is slightly lower.

 

[BirchyBoy]

Hey there. The altitude will reduce your horsepower. I ran some numbers a while back and my drop (in Aurora) was 16% if I recall correctly. I agree with malones - go with what the manual says. Alternatively, you can calculate it using the numbers in the door jamb. It will list the max axle weights, etc. There are online calculators to help you with that.

 

[Gavenger]

The more weight the more strain on the drivetrain. Although we can assume GMC under reports the max tow capacity for liability reasons, I agree with the above statement of staying within the limits for safety and warranty purposes. The biggest issue with towing weight is not the acceleration but the braking. As your vehicle didn't come with the brake controller you'll most likely have one installed. And just make sure you plan ahead while driving. There are aftermarket brake posada that ares better rated for towing, so you could go there if the stock pads are not reassuring enough to you after a few tows are completed. I don't see you having to much difficulty with your set up though.

 

[BirchyBoy]

Amen on the braking. Get a good trailer brake and get it calibrated correctly. It makes all the difference in the world, as does changing your driving style.

 

[malones99]

Towing laws differ from state to state, such as if you need a sway bar. Braking is #1 concern. I assume with your trailer weight, all states say you need a brake controller and a sway bar, weight distribution hitch. I will be towing my 5700lb (dry) trailer tomorrow up 3 grades from SoCal to High Sierra's. CA law is very clear, over 3000lb pounds must have a brake controller, sway bar, weight distribution hitch is optional (I have the Max trailer package, 3.42, integrated brake controller, air shocks). I will let you all know tomorrow evening how it went, I will probably add 500lbs to the trailer with water and supplies.

---------- Post added at 08:43 PM ---------- Previous post was at 08:38 PM ----------

BTW, in the Cajon pass there is a "run away vehicle" gravel ramp, I have seen semi's and light duty w/trailers in their. Most major grades have a vehicle brake check area. Don't be that person! On my old 99 Suburban I took it to Camping World and had them install a brake controller, IIR it was around $200 including installation.

 

[Gavenger]

Do yourself a favor and get the controller. You will never regret it. I'd recommend the weight distributing hitch as well.

 

[cfendya]

Thanks all for the replies! I'm definitely going to get a good brake controller. Looking at the P2 right now as the P3 seems to add "profiles" so if you pull multiple trailers you can easily change things around.

That said, it looks like there is a factory harness option with Tekonsha but I'm unable to locate the hook up under the dash. Anyone have any idea where the harness/plug in for it is?

Thanks again all!!

 

[malones99]

Here is my report, first, my Tahoe has the max towing package (3.42 gears, integrated trailer brake, rear air suspension, it is also a 4x4, rated at 8200lbs for towing. I have a 28 foot travel trailer that is 5700lbs dry. Since I am dry camping for 5 days, I need the water and propane topped off. I figured with wife and three kids worth of "stuff" we add about 1200lbs including water, propane and gear. That brings my trailer to 6900lbs, well within limits.

Setting up the hitch (tahoe has 20" wheels): I had to adjust the hitch to a lower setting (previous setting was for a 99 Suburban). The tahoe is 3 inches "taller" at the hitch than the OBS suburban. I was contemplating the weight distribution bars, do I need them or not, I figured with the air suspension I probably didn't, but in the back of my mind, why put the extra strain on my tahoe, so I did add the bars, I also installed the sway bar (remember you MUST have a sway bar in CA if the trailer weighs more than 3000lb pounds), and finally hooked up the electrical.

I then went to the local school parking lot to setup the brake controller, very easy to use.

Then off we went (forgot to mention Tahoe was topped off with premium gas, I always use premium for towing, 26 gallons). Acceleration was great merging onto the freeway (tow/haul mode is on). First grade was the Cajon Pass, not a very difficult grade 3-4% if that, 7MPG, I was in the lane next to the truckers lane, average 52-57MPH, not bad. Got onto the 395 north, 17 miles of 50MPH max for road construction (what a pain). After that 55-65MPH, 13-15MPG. Arrived in Bishop, topped of gas, had lunch, back on the road.

Second grade (IDK the name) is a few miles north of Bishop, much shorter than Cajon, but much steeper, 4-5%, averaged 4MPG, but only took 15 minutes.

Now in the high country, with the third and final grade, again steep and short, I would guess same percent as second grade, 4MPG also.

We arrived at our campsite at 4pm in the afternoon, leaving at 7am in the morning. Not 1 issue with the Tahoe, trans temp did not get hotter than 205, engine oil temp did not seem to rise much. I set the cruise to 60 MPH, 80% of the time, with tow/haul on the duration of the drive. Granted we did drive through the desert in the morning, I would guess 3-5 degrees hotter for the fluids if driving during peak temps.

Disclaimer, we drove from elevation of 1200 feet, to June Lake at 6700, not a whole lot of braking, but when I needed to brake you really couldn't tell the trailer way their. It took my wife and I about 15 minutes to setup the brake controller, read the manual!

Interesting items I noticed, only 1 time did the electric fans got to "max" speed, pulling out of Bishop (98 degrees) to start the 2nd grade, they stayed on the whole grade, as soon as we "leveled" off, they decreased speed. Going from a 4 speed with 3.73 (OBS Suburban) to a 6 speed with 3.42, I felt the Tahoe "pulled" better, the horsepower is probably a significant factor, 100 more HP than the vortec 350.

Just my $.02 on towing with the 15's.

 

[Gavenger]

Good to know! My expertise with that route is with my dad's 2500HD with a duramax and similar sized trailer. I'm curious how my tahoe will handle that route. My tahoe had the max trailer package but with the 18" wheels