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Last weekend I bought a hi-lo towlite popup camper. It weighs 3150 empty and is 24ft long. It's a little bigger and heavier than I wanted, but it was all I could find without spending >$14k on a new camper. I've had some negative reactions from armchair people online about this bieng crazy and unsafe, despite having a wonderful experience towing it back home. Therefore, in order to have hard evidence for myself, the internet, and any possible insurance claims, I will be putting the niro and this trailer through the SAE J2807 tow rating tests.

After seeing the videos from ECOBRAP, and his results, and feeling the handling myself while driving it home from the dealer, I feel very confident that this car can tow this trailer safely without major mechanical failures.

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I'm an engineer in the automotive field and in my opinion the niro wasn't given a tow rating in america primarily for liability and market reasons. There's not enough overlap between people who like towing and people who would buy a niro, and Americans love to tow their big trailers at 75mph down the freeway and then sue when something bad happens. :rolleyes:

The trailer brakes are very strong and work well with my brake controller (Kurt Echo bluetooth) so that the brake pedal "effort" for a given rate of deceleration is the same or nearly the same with the trailer as it is without the trailer. So the brakes aren't under excessive wear or strain.

Since the niro has a DCT and no slushbox, I'm not worried about the transmission overheating. At 55mph on level ground, which is the speed I plan on towing at, I was at maybe 40-50% pedal in 5th gear. I will be confirming that when I get my bluetooth OBD and can set up gauges for this and other good info. The niro tells you almost nothing about what your car is doing, which is super annoying. One thing that was annoying is that at speed, the battery drains until I have one bar left, and then the engine is left doing all the work. However, that battery fills up quick as soon as I slow down, and the motor gives me tons of extra oomph to get me back up to speed no problem.

While the niro is in the shop today getting airbags installed, Using a regular hitch I got 1-2 inches of rear suspension drop with the trailer. While driving the bumpy uneven Michigan roads, I had no suspension travel issues however. Even still, this will definitely wear out my rear suspension components faster, which is an acceptable expense. I ordered a weight distributing hitch, and will see if I use it or not. I still have to do all the weighing of things like tongue weight and axle load.

I don't plan on going farther than a couple hours distance with the niro. If I want to go farther, I'll rent or borrow a truck.


The SAE J2807 tow rating standard is a series of real world tests used by automotive manufacturers to certify a vehicle's tow rating with a given trailer weight and shape. These tests are quite easy to perform with the exception of one. The thermal test is an 11 mile stretch in Arizona with an average 5% grade that must be performed with an ambient air temp of at least 100 degrees. You must maintain a minimum 40mph while running maximum AC up this road. Since I have no plans of ever going to Arizona and this is far more extreme than anything I'll see in Michigan, I'll be skipping this test. The biggest hill I have in my area is a 0.3 mile 9.5% grade hill and the niro pulled it up that hill on my way home no problem at 40mph.

The rest of the tests can be performed and verified using nothing more than a smartphone with an accelerometer data logging app and a video camera. The hardest part is finding a low traffic 12% grade hill to do the launch tests with.

The SAE J2807 standard is easy to find with a google search. The tests are actually pretty mild:
Acceleration
0-60mph in 30s
0-30mph in 12s
40-60mph in 18s

Hill
on 12% grade hill: 5 launches from 0-16 feet in 5 minutes going uphill
same as above only downhill
The parking brake must hold on 12% grade hill uphill and downhill

Handling
vehicle must understeer between 0.1 and 0.4 lateral g force (find a big parking lot, accelerate while driving in a circle and make sure you have to turn the wheel in towards the turn as you accelerate to 0.4g side force.)
trailer sway >0.10 trailer sway damping ratio at 60mph without sway control (put smartphone accelerometer data logger in trailer, give the steering wheel a quick tug at 60mph, look at the logged data to calculate this)

Braking
stop 20mph-0 in 80ft without axle brakes, remain within your lane (there are other braking tests for trailer weight <3000lb)

The rest of the standard deals with setting up your vehicle and the test trailer parameters, but since I'm only looking at my specific setup, that doesn't matter.

All in all, these tests look both easy to perform, and easy to pass. I would not attempt this with a non popup camper. I plan on publishing the results I get here and maybe on youtube. If I don't like what I get, I plan on looking for a cheap used truck to replace our spare car. The wife wants me to have a truck anyways "because it would suit me". I'm a little stubborn, but not dangerously stubborn.
 

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@zimirken, welcome to the forum.

Good luck with your summer project, let us know if everything work out good! (do not forget that ECOBRAP did their test with an EV model that has a higher HP and torque that the HEV)


** but personnaly, i still do not recommended towing with a Niro.
 

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I'm an engineer in the automotive field and in my opinion the niro wasn't given a tow rating in america primarily for liability and market reasons.
Also SKU issues. In some European countries, a tow package is available. I would assume it has upgraded brakes and cooling.

Mine does that in heavy inclement weather on 3-5% grades without load or exceeding 65 mph. Not a good sign for towing. Possibly if the algorithm was changed, but even so.
 

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Recently I did a little research to find what the differences were between the EV and the HEV to get a better idea of how the HEV would tow.

ECOBRAP did some very good testing and made that info public which I thank him for doing that.

The EV model comes with stiffer and/or taller rear springs than the HEV to handle the extra weight of the battery pack. There is about 1,000 pounds of maximum weight difference between the 2 vehicles. The front and rear brake rotors are also about 1” larger on the EV than what is on the HEV. This also means that the brake calipers should be different too.

In my personal testing, I have loaded down my HEV with enough tools in the cargo area to compress the rear of the car just over 1” compared to no weight. It took a LOT of tools to do this(2 portable tool boxes packed full, a Dewalt tool bag fully loaded, a small cordless air compressor, my luggage for a week, along with multiple cordless power tools. All of this had a total weight somewhere around 200-250 pounds(I’m guesstimating here).

I have been considering adding a trailer hitch on my Niro to haul a small 5’X8’ trailer for runs to my local home improvement store so I will be anxiously watching this thread for updates.
 

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Discussion Starter #5
I have been considering adding a trailer hitch on my Niro to haul a small 5’X8’ trailer for runs to my local home improvement store so I will be anxiously watching this thread for updates.
Getting a hitch installed from the place the dealer recommended was the first thing I did with the car. I have a same size trailer I use for hauling furniture, lawnmower, plywood, etc. It pulls it just fine, no trailer brakes. Once I even loaded about 2000lbs of concrete bags to lay a pad and pulled it. I only went like 45 on back roads, but it did it just fine. Braking was slower, and you could really hear the whine of the motor under regen.

I just received my bluetooth OBD module, and now I have torque pro set up on my phone so I have gauges of all the things I want including engine load %, rpms, coolant temp, pedal %, etc. Kia really didn't give you any info about the cars status at all. I'll also use this to make a chart showing engine load, speed, and battery% while taking a test drive which I will of course post.

My next task is to find a scale and get a weight on each axle with and without trailer, trailer overall weight, trailer tongue weight, changes when using a WDH, etc so I know I'm not overloading the axle ratings. I'll be doing this with a full water and propane load, and maybe some cinderblocks in the trailer.
 

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Be careful with a weight distribution hitch. They were intended to be used on a vehicle that has a true frame, not for a unibody car.

One thing I have noticed on the stock coolant temp gauge is it is truly just an idiot gauge. From 175 degrees till 210 degrees the coolant temp gauge does not move at all.
 

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Discussion Starter #7
Be careful with a weight distribution hitch. They were intended to be used on a vehicle that has a true frame, not for a unibody car.

One thing I have noticed on the stock coolant temp gauge is it is truly just an idiot gauge. From 175 degrees till 210 degrees the coolant temp gauge does not move at all.
I only bought it just in case I go over the rear axle weight limit. If not, i'll return it.

Using torque pro the coolant temp is in increments of 0.1 degrees F and I can watch it go up when the engine turns on while sitting and then go down once it turns off.
 

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Discussion Starter #8 (Edited)
I didn't get a chance to do anything with the trailer this weekend. But I did get an OBD module and torque pro. Got some interesting data.



70mph steady state
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Braking
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heavy accelerating
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A couple observations:
The engine likes to stay at 50% load, and during normal driving will usually stay 50-60%, with the electric motor making up the power difference. Engine output seems to be regulated more by shifting gears. If the battery is low at speed, it will downshift to 5th and stay at 50% load, but charge the battery. Under moderate acceleration, the engine load still stays at 50% and power output is regulated by electric motor and downshifting. Only under heavy pedal does the engine load go up. Coolant temp tends to stay between 180 and 200. Regenerative braking power goes way down in the area of 15mph - 0mph. Just pushing a little on the brake pedal at a reasonable speed applies 20-30kW of regen brake.

When the car is on and parked, it draws about 0.6kW without AC. (the gauge may be inaccurate at this power level though) The coolant temp drops to ~160 by the time the engine kicks on, and heats back up to 190 quickly. The AC draws about 2kW. (when I tested it, I don't live in arizona though)

I can't for the life of me find a PID for current gear. I would also like to find a gas pedal percent PID, as relative throttle isn't related to the pedal. Since the electric motor rpm is always active, I think I might make an equation in torque pro to calculate the current gear based on speed and rpm.
 

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Torque Pro
What would be needed to recreate what you did... OBD reader, Phone APP....ect. ect.
Can this info be displayed on the car 8" screen.?
I got a generic ELM bluetooth obd reader off amazon. Torque pro app. Some extra data for the niro here

I know there's a couple ways you can display the data on the car screen, but I haven't messed with them.
 

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You would have to hack Android Auto to have the car mirror your phone screen. There are some how to dos online, but they as always, seem to require prior hacking skills to use. Torque Pro is an Android app only.

The same screen projection can be done from a jail broken iPhone.
 

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Discussion Starter #13
I've got some results for your guys.

I went for a short drive with the camper with a full water tank(250lb) and full propane(60lb). The airbags recovered all of my suspension travel at 50psi to the point where I had to deflate them to get the hitch out from under the camper. They also made the ride waaaay better. While the damping ratio seems good on feeling, there was still a bit more sway than I want, so I will be getting a sway control of some sort. Unfortunately I didn't take any readings for the test.

I passed my first SAE tests though! I went 0-60mph in 24 seconds, and hit 20mph in 10 seconds. This slams through all three acceleration tests. I certainly had traction issues starting out though, which is to be expected.

I got to do a couple weights on the car too, and I am under both the vehicle limit and the axle limits. 1750 front, 1700 rear, 500 tongue. I don't completely trust the scale accuracy though, since I was doing the weighs on the edges of the scale and not the center. I could drop probably 175 pounds of tongue weight if I had an empty water tank, as it's in the front of the camper. This was with just me (200lbs), half a tank of fuel, and the standard car junk. It was not emptied or anything special.

Alright, the part we've all been waiting for, pictures!

All of these were at 53-55mph, on relatively level ground, in sport mode.

6th gear
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5th gear
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4th gear, note the battery is bieng recharged. However I have to manually select 4th to recharge the battery at speed.
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Enjoy.
 

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I didn't get a chance to do anything with the trailer this weekend. But I did get an OBD module and torque pro. Got some interesting data.

60mph steady state (pic shows 1308 rpm)

70mph steady state (pic shows 2307 rpm)
Very interesting information. I'm a bit confused about the rpm at 60 and 70 mph steady states, though. At 60 mph, engine is turning 1308 rpm. IF IN THE SAME GEAR, at 70 mph rpm would be 1308 x 70 / 60 = 1526 rpm. But yours is going 2307 rpm, rotating 1.51 times as fast. Given steady state conditions (and no up/down grades), I've never heard of a car shifting DOWN at higher speeds, yet this would seem to indicate yours does. Transmission specs I've seen indicate that a gear ratio 1.51 times the higher gear ratio only occurs up to maybe 4th gear, so it just seems weird to me. Other numbers seem reasonable. Any thoughts (as you're obviously a technical guy too)?

Oh, and what is R THR?
 

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Looks like the only advantage to 5th gear vs. 6th is a slight drop in coolant temp. The load, battery draw and other measurements all look to be what one would consider "better". So I would assume better fuel economy in 6th. Interested to see if that holds true.
 

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Very interesting information. I'm a bit confused about the rpm at 60 and 70 mph steady states, though. At 60 mph, engine is turning 1308 rpm. IF IN THE SAME GEAR, at 70 mph rpm would be 1308 x 70 / 60 = 1526 rpm. But yours is going 2307 rpm, rotating 1.51 times as fast. Given steady state conditions (and no up/down grades), I've never heard of a car shifting DOWN at higher speeds, yet this would seem to indicate yours does. Transmission specs I've seen indicate that a gear ratio 1.51 times the higher gear ratio only occurs up to maybe 4th gear, so it just seems weird to me. Other numbers seem reasonable. Any thoughts (as you're obviously a technical guy too)?

Oh, and what is R THR?
Ignore that first picture. I posted the wrong one.

Thats relative throttle. I'm guessing its some sort of percent throttle opening?
 

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Discussion Starter #17
Quick post, got a screenshot while my wife was driving on the freeway at 75mph. Engine load and temps and stuff was about the same as when pulling the camper at 55mph, so that settles the driveline capability. Also, I calculated that I'd be towing the camper <1% of the time. At 5x wear rate thats only like 5000 miles.

Here's the screenshot at 75mph.
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I also noticed that at 60mph in eco mode, the car will charge the battery at 3-6kw until reaching 65% charge, at which point the engine will turn off and the electric motor will draw ~9kw. However going up a hill will kick the engine
on and reset this cycle until the battery reaches 65% again.
 

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Wow! That is some good facts, and not opinions! The Niro tows considerably better than I expected. This could explain the video that KIA put out prior to the release of the Niro showing it flat towing a car.

The 5th gear vs 6th gear towing was VERY interesting. Thanks for the information!!!!
 
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