Towing from Portland to Lake Shasta

[PNWcubbies]

Hey TMC members, I just completed a round trip from Portland to Lake Shasta (a little over 800 miles). Tow vehicle is a 2019 GMC Sierra AT4 with a 6.2L gas engine, and the boat is a 2022 25 LSV on a triple axle. Tow capacity of the truck is 9100 lbs, with a payload of 1474 lbs. I towed the boat with about 15% fuel, and estimate that the total towed weight was close to 9500 - 10,000 pounds. We are a family of 5, and I estimate our payload to be around 1700-1800 pounds. Needless to say, I was pretty stressed out about this trip, as I've never towed this much weight, exceeding the tow and payload capacity of the truck, through the Grant's Pass and Siskiyou mountain passes in Southern Oregon and Northern California which are no joke. I like to do things "by the book," and tried hard to rent a 3/4 ton or 1-ton for this trip, but no luck. My 3/4 ton truck reservation was actually canceled on me by the rental company a few days before the trip. I also considered asking a friend to borrow his 1-ton truck for the week, but thought better of it since I hate borrowing stuff. So alas, I decided to brave the trip using my 1/2 ton Sierra. 

The truck towed the weight beautifully with no issues whatsoever. I'm sure I was straining the transmission on some of the steep climbs, especially since I was doing about 60-65 on some of the steepest climbs, to pass up the big rigs. The engine temp never exceeded 200, and probably topped out at 195 max. I did some light braking on the downhills, primarily down-shifting to 5th gear (10-speed transmission), which worked beautifully. I was primarily hovering around 2600-2800 RPMS, but would climb close to 5000 RPMS when accelerating on the inclines. I think I also got lucky, as the outside temperature remained in the high 70's the whole trip. I've done the trip in the past with outside temps exceeding 110 degrees, but I was towing a significantly lighter boat (Axis T23).

Anyways, I just wanted to provide this information in case somebody else had similar reservations. Yes, I know that this exceeds the recommended tow capacity and payload, and yes, I would ideally have wanted a 3/4 or 1-ton truck to do the trip, but my 1/2 ton GMC Sierra accomplished the task effortlessly. BTW, I did install rear airbags on the truck to help with the minimal amount of squat that the tongue weight was causing, but only needed about 16PSi in the airbags to get completely level with the truck and trailer. Just take it nice and slow (although I was averaging about 70-75mph on the straightaways), downshift to spare your brakes, and reduce weight as much as possible (I actually was able to get down to 1% fuel on the trip back home to Portland). I'll have my transmission inspected in the coming days to make sure that everything is still running smoothly, and will certainly let you guys know if I find any damage. Hope this helps!

[hunter77ah]

Just curious, what was the mpg?

[PNWcubbies]

It was 8.9mpg. I probably could’ve done better if I wasn’t in such a hurry to get home. I filled up in Shasta, once more in South Umpqua, and arrived into Portland empty, so 2 full tanks of gas. My gas tank is pretty small at 24 gallons. 

[Pnwrider]

2 hours ago, PNWcubbies said:

 My gas tank is pretty small at 24 gallons. 

This is my biggest issue with the gm half tons. When I read my build sheet I could have sworn it said 34 gal tank, but I learned the hard way on the first fill up. I called around to several companies that make extended replacement fuel tanks, but they only offer them on the diesel version (due to the evap canister on the gasser). 

[oldjeep]

I think that is pretty standard size for a gas pickup.  My 09 ram had a 26.  My 2018 has the optional 32.

[Pnwrider]

6 hours ago, oldjeep said:

I think that is pretty standard size for a gas pickup.  My 09 ram had a 26.  My 2018 has the optional 32.

My F150 had a 36 gallon tank. The range was awesome. 

[oldjeep]

1 hour ago, Pnwrider said:

My F150 had a 36 gallon tank. The range was awesome. 

So about a 720 mile range?  Nice.

[jjackkrash]

The new GM half tons are 24 or 28 gallons depending on trim level (nicer trim = lower capacity).  My new Tundra 1794 edition has 32 gallons and some change IIRC.  Which seems fine for a half ton.    My big diesel has 36 gallons which is nice until I hook the fiver to it; then 36 gallons does not last that long at 6-7 MPG.  

[UWSkier]

26 gallons on my 2016, which isn't enough when towing the TT.  I always keep a full 5 gallon jerry under the tonneau when towing that pig around.

[dwc032]

My buddy has the same truck, but with the Duramax.  His main complaint is the small tank.  No way i'd have a combined weight of 18-19k in a half ton truck especially on a long drive, I don't care what the manufacture says it can tow.  Glad it all went well though.  

[Stevo]

F350 diesel long bed comes with 50gal , the big tank is definitely a nice benefit 

[malibu2004]

Sounds like you need a 3/4 or better with that size of boat and family.

 

[Kenw]

Does your trailer have surge or EOH brakes?

If surge, Did you have any issues with the brakes heating up on the descents?

Thanks

 

[dwc032]

19 hours ago, Kenw said:

Does your trailer have surge or EOH brakes?

If surge, Did you have any issues with the brakes heating up on the descents?

Thanks

 

Mine will literally look like there on fire down a steep grade there smoking so much.  Mine didn't do it going down into Shasta, but they have in the past.  It is going in to get looked at in the spring.  I posted this last fall and had the dealer fix it.  Well obviously it didn't get fixed.....lol