Help calculating towing weight

[green]

I have access to a 2019 Kia Sorento SX AWD V6 to pull my new to me 2005 if I install the hitch. Before I do this I’d like to verify the numbers.

The max tow capacity is 5000lbs. My understanding is that the with the factory trailer, 50hp Honda outboard, and misc standard equipment is 3500-4000 lbs. I don’t have a way to weigh it before I have the ability to tow it.

The GVWR (and GAWR?) of the trailer is 4200lbs.

I think this leaves me with up to 1000lbs of cargo in the tow vehicle.

Does this tow vehicle allowance need to account for people in addition to cargo? I was confused by the service person I spoke to on the phone. He said 2 people are generally accounted for already, but I need to count everything else and multiply by 10. So if two kids with a combined weight of 100lbs join 2 adults this would be 100x10=1000 lbs, leaving no wiggle room for cargo.

So my question is what do I need to account for in the weight inside the tow vehicle?

[Be Free]

GVWR for your vehicle refers to what the vehicle is carrying. It is not specific to towing. It is the actual weight of the vehicle and everything in or on the vehicle that the vehicle is supporting on it's tires and suspension. It includes all of your cargo, all of your passengers, and (if you are towing) the tongue weight of the trailer.

GVWR for the trailer would be the weight of the trailer, the boat, engine, fuel, and everything else in the boat. Again, it is a maximum that the suspension and tires can safely tow.

GAWR is the maximum weight that can be placed on each axle. It is often different between the front and the rear axle. The numbers will often be different between the front and rear axle and will certainly be different between the vehicle and the trailer axle.

tldr: GVWR is maximum weight allowed on the suspension of the vehicle or the trailer. GAWR is how the weight is distributed between the axles.

The towing capacity listed by the manufacturer has some assumptions and tends to be influenced by marketing. It's best not to get too close to it unless you are dealing with a vehicle that was designed with towing in mind. The average passenger car or light SUV does not meet that definition. The towing capacity usually accounts for the curb weight of the vehicle and the driver. Nothing else.

I have no idea where the service person you spoke with came up with the "count everything else and multiply by 10" rule. Maybe I'm extra dense tonight (this morning) but I can't make any sense out of it.

In general in your particular case here's how I would figure it.

Assuming worst case and you are going to load the trailer to the max you will be pulling 4200 pounds. The 4200 pounds the maximum weight that the trailer can carry on its suspension. For the purposes of this example I'm just assuming that you have maxed out the trailer without knowing how it is distributed. Note that North Carolina requires brakes on boat trailers over 4000 pounds.

I have an X, an aluminum trailer, and a Honda 40 (same weight). With trailer, boat, batteries, fuel, and engine I'm at 3655 pounds. It does not take much gear in the boat to get well north of 4000 pounds being pulled.

Assuming your tongue weight will be approximately 10% of your trailer weight. That's the equivalent of 420 pounds of cargo.
GVWR of your vehicle is 5622 pounds.

Curb weight is 4101 pounds. Curb weight includes all fluids and standard equipment is present but no passengers or cargo.

5622 - 4101 = 1521 pounds for passengers and cargo.

1521 - 420 = 1101 pounds left after trailer is attached.

Best case you have 1101 pounds available in the vehicle for people and gear. It is possible that the number is lower due to GAWR constraints but I have no way of knowing how you will be loading the vehicle.

I don't want to scare you or try to get you to buy a new tow beast. I knew someone in southern Georgia who pulled his "M" with a Dodge Caravan. I don't know how he ever got it back up a ramp. The numbers for your Kia are not much different that they were for the first vehicle I used to pull my "X". Who am I kidding, yours are a bit better. It was a borderline call and I probably abused the suspension but it survived. If you are not pulling it very far and you are not pulling it in the mountains you probably won't have issues.

[kurz]

Go for it, I see no problem.
Watch for that you empty the boat that much you can. The factory trailer with just 1 axle is the limit, not the car!

[Russ]

How far/fast are you planning on towing?

I had U-Haul install a hitch once and I got home and found they left 1 bolt out where it attaches to the frame.

Next car I did some research and learned it's fairly simple to install a hitch so I went on etrailer.com and bought one with a wiring kit. Then I bought a torque wrench and installed the thing myself. Super easy and $ hundreds less.

[green]

Thanks Russ, Kurz, and Be Free. Most often we'll travel about 2 miles from dry storage to the lake (flat). Once every few months we'll take it about 2.5 hours to the coast on I-40 (flat). Hopefully we'll make it to other lakes in the area on occasion. I could always rent a larger vehicle if we had a really big trip planned.

I anticipate being the slowest car in the right lane.

Be Free, thanks for the excellent summary. It really helped! I have the surge brakes on the 2004 factory trailer.

[Be Free]

+1 on Kurtz. The factory trailer will definitely be the limiting factor. If you don't overload the trailer your Kia should not have any problems towing.

The factory trailer was just barely adequate for the boat. You are going to want to watch out for rust, particularly in the tongue.

Make sure you keep your bearings and tires in order. Service the bearings and brakes every year. You probably won't need to replace anything in the brake system annually but you don't want to try to stop without them. Your Kia will feel the difference so make sure they are working.

Check the date code on your tires. Replace them if they are more than 10 years old regardless of tread wear. Keep the tires inflated to the maximum on the sidewall. Verify the load carrying capacity of the tires. The PO may not have the correct tires on the trailer. (Trust but verify) They should be at least one half the capacity of the trailer. A bit more would be even better.

I prefer bias ply tires on a trailer. They are a bit more forgiving of abuse but they are getting harder to find. If you use radials watch your pressure very closely. Don't mix bias and radial tires on the same axle. Don't mix them at all if you can avoid it.

[green]

Thanks for the handy checklist. Working through it.

[Herschel]

I know this is an old thread, but I was just perusing topics and stumbled over this one. I tow a travel trailer more than my Mac26X, and in the RV world we use the CAT scales at truck stops and similar commercial areas. You can download the app on your phone, pull up on the scale with your rig and get three weights: (1) the weight on the tow vehicle front axle, (2) the weight on the rear axle that includes the tongue weight of the trailer and a major portion of the cargo in the rear of the vehicle, (3) the weight on the trailer axle(s). Unless I am mistaken, you then have the total weight of the rig or gross combined weight of the vehicle (GCWR), too. This allows you to check all the pertinent weight ratings.
https://catscale.com/cat-scale-locator/

[wakataka]

I weighed my rig last summer before heading out for a month on the BC coast. The boat was loaded with food for a 3 week cruise, 4 anchors, 150 feet of 1/4" chain, about 400 feet of anchor rode, stern line, pots, pans, lots of spares, everything needed for a month of self sufficient cruising. I also had a 4hp kicker motor and an 18 foot inflatable kayak on the boat.
The truck is a full-size half-ton Chevy short bed long cab from 1990 with a fiberglass topper. It was about 2/3 full of fuel and had two adults onboard. Here's the weights from Cat Scales-

Front Axel - 2520 lbs
Rear Axel - 3740 lbs
Trailer Axel - 4180 lbs
TOTAL - 10440 lbs

The trailer is a standard MacGregor with a second axel added behind the original one and some reinforcement on the tongue. Tongue weight was about 565 lbs. So the total weight of the loaded boat and trailer was about 4745 lbs. You definitely know it's back there when pulling with a half-ton truck.

[Herschel]

wakataka remarked:

You definitely know it's back there when pulling with a half-ton truck.

I have towed my heavily loaded Mac 26X on its OEM trailer (upgraded to two axles) with a 2007 Ram 5.7 with four-speed transmission on relatively level roads (Orlando to Atlanta and back) with considerable ease. I tow my 7,900 lb. travel trailer with my new-to-me 2020 F-150 3.5 EcoBoost with max tow package and 10-speed transmission without much problem. Twice from Orlando to San Diego, once on I-20/40 (and a side trip to Provo, UT) (more steep grades) and once on I-10 (flatter). You might find that newer "half tons" with the right tow package/transmission are good upgrades and make life easier on the road with a 4,800 lb. tow.

[Herschel]

Here is a great tutorial for using the CAT scale app.
https://www.forestriverforums.com/forum ... 90615.html

[dlandersson]

Unless you have a lot of gear, you should be ok. OTOH, this is not the time to take chances with your tires.

If it were me, I'd carry as much as possible in the Kia and load your Mac when you get to the ramp area.

[ris]

In a Kia this might not help but we have a silverado 1500, 2 wheel drive and we put all the real heavy stuff in the back of the truck. The batteries, 10 gallons of water plus clothes, and kitchen stuff ride in the boat. The dinghy, dinghy motor, anchors with chain and all the other heavy stuff rides in the back of the truck. This is the way we pulled it from Florida to NY last summer. We used the boat as our camper on the trip up and back. If you travel long distances like this put two axles under that boat trailer. Putting two axels under the boat trailer was our first mod. I bought the boat drove 60 miles home and a week later put the boat in the lake and put 2 new axles under the boat. We use the Mac as a trawler so no sailing stuff on board, like mast and rudders.
Richard