Tow ratings

FishAr · March 7, 2016

After doing some calcs I'm seriously disappointed in the manufacturer's hype about these tow ratings. Or I'm confused about internet towing experts calculations. Not sure which.

My last truck, 2015 Colorado crew cab z71 4x4, advertised 7000 pound tow rating. I took that at it's word, and pulled a 4400 pound (over 5000 pounds loaded) camper with it. It handled it alright. Then I traded for a larger camper (advertised 29ft, over 25 ft box, 5700 empty) and I actually pulled it for 150 miles with the colorado. I had no trouble there either but I knew I didn't have enough truck.

So I traded for a 2015 silverado double cab 4x4 z71. It pulls my new trailer fine. I'm not yanking it around at breakneck speed but I have plenty of power.

I had wdh and sway bar on both these trucks and campers. Both trucks had ARE camper shells on them.

Wife and I have rented a year round spot in florida after our winter trip down there this year, and we've discussed buying a large trailer to just leave down there. These trailers empty push right up against the advertised 9200 pound towing capacity of my silverado. Although the plan wouldn't be to move it, I wanted to make sure I could. Plus I'd need to haul it from the dealer to my site.

When I got in depth on my towing calculations it seems that my current trailer at 5700 empty and maybe 6700 loaded is at the limits of safety with my silverado, and was way over the limits of safety with my colorado.

That was using this site:

http://rvtowcheck.com/rvtc_calculator.html

and this one:

http://changingears.com/rv-sec-calc-trailer-weight-tt.shtml

I guess when I pulled that 32 foot travel trailer back in the 80's with my 1978 chevy heavy duty half ton (Big10) I was really dangerous, but I don't remember having any trouble with it.

Someone please tell me what the straight scoop is on this?

FishAr · March 7, 2016

I know that both these calc sites have safety margins built in, and I like safety margins.

Does chevrolet not have a safety margin?

newdude · March 7, 2016

At the limits of the Silverado? What gearing do you have? I can see the issue with the Colorado as 6700lbs is right on the door, plus if you add in fuel, you and however many occupants and luggage...

FishAr · March 7, 2016

At the limits of the Silverado? What gearing do you have? I can see the issue with the Colorado as 6700lbs is right on the door, plus if you add in fuel, you and however many occupants and luggage...

3.42

5.3L z71 4x4

With those calculation sites, once I add in wife, me, and dog, and the ARE shell, and the stuff in the back of my truck (golf clubs, dog kennel, cooler blocks for camper jacks, 3 ton floor jack in case I have a flat) they say I'm good but not by a lot.

FishAr · March 7, 2016

One the one site I just noticed if I change my tongue weight on the scale from 12% to 10% I get a reading of 8500 pounds instead of 7083.

newdude · March 7, 2016

Both of those sites are interesting in that they go against each other. I put my truck in both, the first one gave me calculations that equaled the published tow rating, the other gave me almost 5000lbs less than GM's published rating.

GM calculates them as follows:

Maximum trailer ratings are calculated assuming standard equipped vehicle, driver and required trailering equipment. The weight of optional equipment, passengers and cargo will reduce the maximum trailer weight your vehicle can tow. 10 to 15% of the trailer weight is the recommended trailer tongue load.

So, they are using most likely a WT trim truck, with zero options other than towing equipment, engine and gearing. So, it would seem that GM (and really, all truck mfg's) aim to the max of the truck, with nobody in it, and the lowest trim possible, publish the specs, and then CYA with that calculation system they use I quoted above. So, 9200, take away lets say, 500lbs for people, 500lbs for cargo, you are down to 8200lbs. Then lets say, an LT truck adds 50lbs for equipment, you are down to 8150lbs.

Should OEMs calculate their weights more honestly? Yes. Do a lot of people not buy enough truck? Yes.

Best thing I would say is, take your stuff to a truck scale and see where you are at.

FishAr · March 7, 2016

Yes, I really need to go to the scale.

I put the truck in as 5400 and then added 950 pounds for people, dog, shell, golf clubs and other stuff in the back.

I honestly don't even know what the truck weighed when I bought it, I think I got 5400 from some internet site.

FishAr · March 7, 2016

And then I calc it with just me in the truck and adding 180 pounds for the shell and I get 9220 pound I can safely tow, while the advertised rating is 9200.

This is way too confusing for mortal men.

I'm guessing that if wife and I buy a florida trailer around 9,000 pounds and 37 ft or so that I can get it to the campsite without breaking the law or tearing anything up, and get it home one time (1000 miles) if something went wrong like the campground going broke, or my Lab biting another camper or something. Not that my Lab has ever bitten anyone.

My main concern is getting it there once (hope to buy it down there but who knows) and then having the capacity to move it home once or to another campground if something went wrong where I'm at.

As much as I'd like to have a duramax 2500 or 3500 I'm not buying one. Before I went to the 65 grand expense of that to pull a trailer I'd just buy a motorhome I think.

Johnnynovo · March 8, 2016

You should be able to move it to your site just fine if you buy it close enough. You would need a weight distributing hitch, sway bar, and probably E load tires. I went thru the same thing this past weekend. I bought a trailer that is 8500# dry and moved it 45min to my site just fine. Truck has plenty of power, my hitch is rated for 12000# and 1200 tongue weight. It was just me in the truck and nothing in the bed. I went thru running calculations just like you did and was nervous when I picked it up. Trip went well with no complications (I was actually surprised how well it did). Now I'm set for the summer. I would think GM would have a margin for safety built in like everything else has on the truck. If I was going to tow a lot, I would think about a bigger truck.

Nathan79 · March 9, 2016

Tow capacity is not just one number in a brochure. It is a combination of GCWR - actual truck weight, rear axle capacity, tire capacities, receiver rating, and payload (GVWR-ACTUAL truck weight). Considering the trailer may have anywhere from 10-15% tongue weight there are many variables at play.

Johnnynovo · March 9, 2016

Also a lot of dealers are willing to drop it at a local site and setup for free. At least around me.

GsBowtie · March 26, 2016

Tow capacity is not just one number in a brochure. It is a combination of GCWR - actual truck weight, rear axle capacity, tire capacities, receiver rating, and payload (GVWR-ACTUAL truck weight). Considering the trailer may have anywhere from 10-15% tongue weight there are many variables at play.

This is very good advice. It's not just about tow rating. The issue most half ton trucks run into is payload. As you state, you deduct the weight of passengers, and cargo in the bed, plus hitch (tongue) weight from the yellow payload sticker on the door post.

Where are you at when you deduct everything you want to haul plus tongue weight from that figure?

It's up to you and what your comfortable with, but if you wreck and hurt someone the first thing a lawyer will do is calculate your loaded weight and if your over, get ready to start writing checks.

Yes, back in the 80's you were very likely way overweight with your 32 ft rig with your 80s Chevy Big 10, Yes, I remember those trucks and loved that style. Today's half ton trucks are much more capable than that Big 10 was in every way. If I remember correctly, my truck has 1740 lbs of payload according to the yellow sticker, that's over 3/4 ton of pay. Yes, there are safety margins built into today's trucks, but how far are you willing to push those limits?

It's not just about pulling it, but it's about stopping it as well. Traffic in the 80s was nothing like it is today, unfortunately. At 9000lbs and 37 ft long your in 3/4 ton truck territory, without question in my mind. Pulling that with a 1/2 ton truck would likely cause the tail to wag the dog, especially if you encountered strong winds.. In the scenario's you mentioned, I think you'd be better off renting a 3/4 or 1 ton truck (for the 1,000 mi trip). Locally, if I was within all my ratings, I wouldn't have a problem moving it with my truck.

We took a week long camping trip last year, my trailer is 24' long and about 5K loaded weight or so. It was only me in my truck, but I had the front passenger seat and entire rear crew cab loaded with gear and supplies, also had a lot of fire wood in the bed, with other camping chairs, supplies, etc back there also. On this trip my trailer weight loaded was likely higher than 5K since this was a week trip and we had extra clothing, food, etc. There is a possibility I was over my payload rating on this trip. My truck handled it just fine, plenty of power, even up in the mountains and it braked well with the factory IBC. I don't know that I'd want to go much over 7K trailer weight with my truck though, but again everyone has different levels of what they are comfortable with.

The brakes on these new chevy trucks are excellent! Chevy finally got the brakes right. The 88 and 89 silverados I had in the past always felt under braked. Not so with my 15.

Good luck, I hope this helps. Camping is great, I have always enjoyed it.

FishAr · March 27, 2016

We found and bought a 34.5 ft trailer that weighs 7100 empty. It had all the wife wanted except for a washer and dryer, and she really likes the layout.

I'm comfortable with pulling this down to Florida and leaving it. They're putting dual sway bars on it for me.

I also saved over 10 grand in the process against the 9,000 pound trailer we originally had our sights set on.

GsBowtie · March 27, 2016

Good deal, glad to hear that. A 34.5 foot rig is still a huge trailer though and the "dry" weights typically don't include things like propane tanks or anything in the unit. I'd figure around 500 lbs more if you don't load much in the camper, so figure 7600lb. Take your time, run around 60mph or so, (most trailer tires are speed rated to 60mph and if you exceed that for a prolonged period you can overheat them and cause a failure ) and make sure your trailer tires are aired up to the maximum pressure cold. Check the wheel lug nut torque and make sure that is to spec. If your running the stock P rated tires on the truck, I'd air those to the maximum pressure, cold as well to make the sidewalls as stiff as possible. (At least the rear tires) Bring a good stocked tool box and a floor jack just in case.

If you figure 12% tongue weight, that's 912lbs, so depending on your payload rating (if this was my truck for example)

You'd have 828 lbs left for you, other occupants and gear without going over the payload.

Good luck and safe travels. If you could, after you make this run, post an update with photos of the rig and your thoughts about how the trip went.

Johnnynovo · March 27, 2016

Just to add to the discussion, I have the same problem. In Oct of 15 I bought a new 1500. Last month went to the RV dealer and bought a new toy hauler travel trailer. I took the dealers word that my truck could legally pull it. It is a 30' (35' overall). I have a WD hitch and E rated tires and bought helper springs. I towed it home and back out one time to check the weight after seeing a lot of discussion on the internet about weight being a problem. The trailer actually weighed 9500#. I was told it was 8600. My overall weight GCW is 15,400. It pulls and stops great. I'm not using it to go far, 30 min away max (just to the local go kart track for my son). I took my truck up to the dealer to trade in for a 3/4 ton. They said I missed the good rebates and they predict the next round of good rebates to come out this summer. I have a good relationship with the dealer (bought 2 cars and 1 truck in the last year). The salesman went and got one of their truck mechanics to come out and talk to me. He said with the type of towing I'm doing that I would be fine till summer (a couple of trips). He said that they don't see many break due to towing. They have contractors think they can hook their 1500 up to a trailer with a mini ex and haul it from job site to job site to keep things moving and they don't have any problems. He told me that the only things he would be concerned with is the tires and suspension and I had already upgraded those (since put air lift bags in). So from what I understand is these trucks are built very well and if the situation is temporary, going over a little shouldn't hurt. Just keep it to short trips. I'm actually impressed the way they tow. I would have never even got it weighed if I hadn't started reading on the Internet.