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  1. Tongue Weight Scale
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BetterWeigh Mobile Tongue Weight and Payload Scale for OBD II - Bluetooth

BetterWeigh Mobile Tongue Weight and Payload Scale for OBD II - Bluetooth

Item # C51701
Our Price: $84.08
Tongue Weight Scale
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Shipping Weight: 0.08 lbs
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Monitor your towing weight using your smartphone. Bluetooth receiver pairs with companion app to display tongue weight, pin weight, payload, and gross combined weight of your load. Receiver plugs into the OBD-II port on your vehicle. Great Prices for the best tongue weight scale from CURT. BetterWeigh Mobile Tongue Weight and Payload Scale for OBD II - Bluetooth part number C51701 can be ordered online at or call 1-800-940-8924 for expert service.
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CURT Tongue Weight Scale - C51701

  • Bluetooth Scale
  • No Capacity
  • CURT

Monitor your towing weight using your smartphone. Bluetooth receiver pairs with companion app to display tongue weight, pin weight, payload, and gross combined weight of your load. Receiver plugs into the OBD-II port on your vehicle.


  • Scale monitors your towing setup's important load measurements
    • Calculates tongue weight, pin weight, payload, and gross combined weight
    • Lets you know if you need to adjust your load before you tow or haul
    • Eliminates the need for separate or commercial scales
  • Weight distribution feature lets you verify weight distribution system is set up properly
    • See how weight is distributed across axles so you can make adjustments when needed
  • Receiver unit wirelessly transmits towing information to your smart device
    • Connects via Bluetooth for operation
    • Displays weight information through mobile app on your smartphone
  • Fast, plug-and-play installation makes setup a breeze - no tools required
    • Plug unit into the OBD-II port on your vehicle
    • Download free app to your phone and then calibrate
  • Preset calibrations let BetterWeigh automatically pull vehicle specifications using VIN
    • 5-10 Minute guided manual calibration process available for vehicles made before 2008 or vehicles with modified suspension


  • Application: vehicles 1996 and newer
    • Weigh GCW feature requires an automatic transmission
    • Does not work on hybrid engines
  • Smart device OS requirements:
    • Apple (iOS): 10.3 or higher
    • Android: 6.0 Marshmallow and higher, Bluetooth enabled
  • Limited lifetime warranty


  • Will not work on diesel trucks manufactured before 2004 due to OBD-II regulations.
  • Will have limited functionality on vehicles with auto-leveling suspension.

The days of weighing your trailer with a bathroom scale and construction site materials are long gone. Measuring pin weight and payload no longer requires a visit to a crowded weigh station. Avoid the hassle and get all of the needed weight measurements sent directly to your smartphone. This little device does the work for you to provide peace of mind and promote safe hauling.

BetterWeigh is a compact device that easily plugs into your vehicle's OBD-II port and uses vehicle-specific data to measure and monitor your tongue weight, pin weight, payload, and gross combined weight in real time. Whether you're pulling a trailer behind your truck or you've loaded down your SUV's cargo carrier, it's important that you don't exceed the weight ratings of your vehicle or hitch. And BetterWeigh makes it easy to avoid doing so.

Simple, Guided Setup

Setting up BetterWeigh is easy. First, plug the unit directly into your vehicle's OBD-II port, which is typically found beneath the steering column. Open the free BetterWeigh app on your compatible smart device and follow the step-by-step instructions for pairing BetterWeigh to your smartphone via Bluetooth.

Next, the app will prompt you to scan your vehicle's VIN to search BetterWeigh's vast preset calibration database. Many vehicles made in 2008 or later will have preset calibrations. If no preset calibrations are available, the app will guide you through a brief manual calibration process to ensure accurate weight readings.

Manual Calibration for Older or Modified Vehicles

Vehicles older than 2008 or those with modified suspensions may have to be manually calibrated. Follow the guided, in-app instructions to manually calibrate BetterWeigh to your vehicle.

First, enter in your vehicle's curb weight. This can be found on the sticker on the inside of your door or in your owner's manual.

Next, you'll want to find an empty parking lot where you can perform 15 to 20 test runs. For each run, accelerate to 15 mph at varying throttle - this will ensure accuracy under different conditions. Manual calibration only takes about 5 to 10 minutes to complete.

How BetterWeigh Works

OBD-II ports became standard in most vehicles in 1996. This port makes it easy to access your vehicle's computer for diagnostics and emissions testing. The amount of vehicle data available via the OBD-II port has increased over the years, allowing BetterWeigh to tap into the specific data needed to determine weight. Sophisticated algorithms, along with an on-board accelerometer, are then used to calculate real-time weight with superior accuracy within 5%.

How it Works

Let's travel back to high school physics class for a moment. As you may recall, Newton's Second Law of Motion states that the force of an object in motion is equal to the mass of the object multiplied by its acceleration. So, to determine the mass of an object - in this instance, your rig - we just have to take the force and divide by acceleration.

Acceleration is easy enough to determine thanks to the triaxial accelerometer built into the BetterWeigh. Determining the force is a bit more complicated. Basically, BetterWeigh pulls data about your transmission from your vehicle's computer and then uses a customized torque converter model to determine the powertrain effort.

Once the overall mass of your setup is determined, the BetterWeigh will convert this to a weight. Then, to determine your trailer's fully loaded weight, the unit subtracts your vehicle's weight from the weight of the overall setup.

Weights Measured by BetterWeigh

Tongue Weight

It's important to monitor tongue weight and adjust your load when necessary to ensure that you stay within the rated capacity for your setup. Simply put, too little tongue weight can cause trailer sway and too much tongue weight can cause your tow vehicle to perform poorly. You may have difficulty steering, gaining traction, or braking when driving a setup that has too much weight pushing down on the rear of the vehicle. Ultimately, towing with an improper tongue weight can cause you to lose control of your vehicle or cause your trailer to separate from the vehicle. Tongue weight should be approximately 10% to 15% of your gross trailer weight (GTW).

Pin Weight or Vertical Load

If you're towing a fifth-wheel or gooseneck trailer, BetterWeigh will calculate the pin weight or vertical load. This is the downward force exerted by the trailer onto your truck bed. Like with tongue weight, knowing this measurement helps you to ensure that your trailer is properly loaded. An improperly loaded trailer is the number 1 cause of sway. Maintaining a proper pin weight will limit trailer sway and improve handling. This weight should be about 20% to 25% of your GTW.


Payload is important to monitor as well. This is the weight of both the cargo and passengers in your vehicle. Do not exceed your truck's gross vehicle weight rating (GVWR).

The BetterWeigh measures payload in real time, so you can see how every piece of cargo affects your load. This is great for estimating load charges or determining if your truck bed camper is overloaded.

Gross Combined Weight

BetterWeigh measures your rig's gross combined weight to ensure that you're not hauling more than your vehicle and hitch are rated for. To do this, the unit subtracts your vehicle's curb weight from the overall weight of your setup to provide the weight of your trailer.

Knowing your gross combined weight is also helpful to determine whether you can drive over bridges with weight limits.

Weight Distribution

The weight distribution feature measures weight across your vehicle's axles to verify whether your weight distribution system is set up properly. An unbalanced load or improperly installed system can cause dangerous sway conditions.

BetterWeigh does the work for you so you don't have to use a tape measure and do manual calculations when setting up your weight distribution hitch.

51701 Better Weigh Wireless Trailer Tongue Weight Scale, Payload and Pin Weight Scale

Replaces HG103 Haul Gauge Tongue Weight Scale

Installation Details C51701 Installation instructions

Customer Satisfaction Score:

Customer Reviews

BetterWeigh Mobile Tongue Weight and Payload Scale for OBD II - Bluetooth - C51701

Average Customer Rating:  3.8 out of 5 stars   (115 Customer Reviews)

Monitor your towing weight using your smartphone. Bluetooth receiver pairs with companion app to display tongue weight, pin weight, payload, and gross combined weight of your load. Receiver plugs into the OBD-II port on your vehicle.


Surprisingly and thankfully pretty accurate. Being our first travel trailer, I have been maybe overkill on set up for a safe tow. Between the added air springs I installed, the anti-sway WDH, and this Curt BetterWeigh device helping us tune in the weight distribution made for a great pull. No more just making due when I was a kid with headlights blinding aircraft heading to the race track. System knew the specs on truck right away with no additional calibration needed. Will be a five stars when we are able to spend some more time with all the functions.


I think the product is probably pretty good. I only give it 3 stars because the calibration is not easy to do if you don’t have long enough straight level roads with no possibility of hitting a kid running into the street while accelerating quickly. Unfortunately I haven’t found a location here to calibrate it.

Not at all
Russell - 03/14/2023


I am going to keep it. I think it is doing a pretty good job so far, but I do need to get some more experience with it. I have a 2022 Toyota Tundra with the auto leveling air suspension. You can put the air suspension in manual mode as long as you stay below 20mph. This device does all of its measurements at 15mph and below. So far, it seems to consistently yield results that are about 50-100lbs heavier than actual measured weights. I think I need to recalibrate it again and maybe that will improve but if it doesn't, it is still a keeper in my book. I was disappointed that you cannot access the instructions in the app until you plug it in to the truck and then fill out some data for each device. It was not able to get my VIN and then it had no calibration data for it after I manually typed in my VIN. So, plan on wasting your day playing with calibration input when you first get it.


Product does not work on Hybrids and nobody at etrailer new this information a big waste of time on the phone until i called Curt products and they told me after an exhausting 20 minutes that this does not work on Hybrids. etrailer would not give me a refund because they said I had to send it back unopened in the original package. How do I know it doesn’t fit Hybrids when they didn’t even know after a alot of emails I gave up Rotten company to do business with.

I wanted to let you know that our return label covers a variety of returns and that we understand that the part has been tested in your vehicle. It does not have to be in the original packaging. Please go ahead and use our label to return the part.
-- Etrailer Expert Jenny N - 09/22/2022


NOT compatible with KIA Telluride 2022 factory installed hitch system.
This system has an “auto-level” system which cannot be disabled in order to calibrate the BetterWeigh device.


Difficult to setup. Requires setting up and calibration every time you rehook your trailer to tow vehicle. Could be device doesn’t remember last calibration of tongue weight or I’m not understanding instructions. I stopped using it..

You mentioned that it was requiring you to recalibrate each time that you used it. I wanted to ask a few follow up questions. Is your vehicle a 2017 Toyota Tundra? Is the app pulling the present calibration for the Tundra based off the VIN number?
-- Etrailer Expert Jenny N - 06/16/2022


Conceptually, great idea. I was hoping to use it to make smarter decisions on weight distribution of items in the camper to lessen bounce. The process involved in setting up outweighs the potential benefit, in my opinion. I don’t bother with it due to the hassle factor. I will just buy a tongue scale (which I intended to do in the first place). Until I received the 1-year solicitation for review - I forgot I had it! I am sure if I had bothered to reach out to etrailer, they would have helped like they always do, but I didn’t - that’s on me.


Awesome device ! No questions about trailer connection


I have a 2014 f150 4x4 and a 2017 31' Rockwood camper. When I would pull it I would have a bad sway problem. My hitch is an EZ-Hitch and I went through all of the directions and thought my measurements and settings were the best.
Boy was I wrong. I purchased better weigh and went through all the steps which was very easy. My settings were way off. After setting to the camper for a test drive and it had taken care of the sway problem.
Attached are snap shots of my settings before and after.


I like the confidence a gauge provides in confirming whether something is in tolerance or not. This is an excellent gauge. It does require disconnecting and connecting to get a before after reading. If you load the same equipment then mark the locations to avoid a reading each time.


Worked well measuring the weight in the bed of our pickup truck but not very accurate measuring the weight of our trailer.


As much as I wanted to like this, I ended up returning it. My unit was reading a very high tongue weight, and I confirmed it was off by putting my own body weight on the tongue from which it showed the wrong change in weight. Curt (great CS!) sent me a second device and again it was off be several hundred lbs on the tongue. My weight (per a scale method) was around 800 lbs but the Betterweigh came in well over 1000 lbs. Great idea but they didn't work in my case and were returned. I just use a homemade scale for the tongue and a CAT scale for the rest now which gives very consistent results.


Have difficulty setting up still haven't been able to used it since upgrading to my Samsung s21 phone not been happy

Maybe deleting and redownloading the app in google play will reset the settings with your new phone. Plug in the better weigh into the diagnostic port typically below the steering wheel and the app should guide you through to set up your VIN. See if any other Bluetooth connections are present in the vehicle as it will not work if other things are synced. If you have any other specific questions, please let me know and I will try and help.
-- Etrailer Expert Sierra K - 11/23/2021
Still not been 2 years right after I got my s21 phone ,will not calibrat no help from anyone to resolve it. Would not suggest it to anyone, yes it worked great on my s7 .
Michael - 11/22/2022


Overall, I think this is a good product that does what it claims. My problem is that each measurement begins with the instruction "on a level surface". I live in a very hilly area and level ground is hard to find. It is also tough to find free time to set up for use. I am usually rushed to set up and get on the road. All of my impediments to using the Better Weigh" are personal and shouldn't be seen as performance issues with the product.


Did what I needed. #1 Tonge weight was key (I was glad I upgraded to a Class 1V hitch) #2 Weight of Vehicle and Vehicle and trailer Still working with as I change payloads in the Trailer. #3 Also Brake Gain is helpful, still learning. Absolutely GREAT so far.


The devise worked within parameters and am very happy with the results. After installing it and I collected the numbers: I went to the local scales and compared the numbers. They were within the Better Weight parameters. Now I use the Better Weight to check my weight for my trips. If I think I'm close to my Max weight, I'll take the RV to the scales


This should do what I want to check out towing capabilities.


Works as advertised. I used it to position my car on the trailer, the trailer pulled just fine.


i haven't tried it yet


We hooked the (weigh scale) app up to our F-250 diesel truck and entered the vehicle VIN to connect the BETTER WEIGHT device. The VIN can be scanned with a smart phone camera.


I had a chance to install the Better Weigh in the OBD port on my old Escalade EXT (Avalanche, LOL). It's definitely a bit time consuming and I think best done in a quiet, flat shopping mall parking lot early on a Sunday morning. The disconcerting thing was I got two different weights when I calibrated two different times with my travel trailer hooked up. I switched road surfaces from bumpy gravel to smooth pavement and I will chalk it up to that.

I like knowing that I am within tow ratings. I found the brake controller and weight distribution functions a little confusing so I just kept my settings the same on the current trip until I have more time to dig in and learn how to use that.

Overall, I think the Better Weigh is a pretty good value as long as it's relatively accurate. Going to scales or buying a scale capable of weighing trailers both get pricey.

After a year I can’t say I am convinced the Better Weigh was a good purchase. I’m glad I have a better idea of the weight, but in the area where I live it’s difficult to find an empty parking lot to use it accurately. Definitely cannot do it on busy city streets.
Gary - 05/19/2021


For me, the BetterWeigh was not worth the money. The instructions were a little difficult to follow. My tongue weight was better adjusted visually. It might be more useful to people who trailer a different variety of payloads. I trailer the same load each time.

You mentioned that your tongue weight was better adjusted visually and I wanted to see if you could explain in more detail what you meant.
-- Etrailer Expert Jenny N - 06/14/2022


Works as advertised right out of the box. Great to know your payload and / or trailer tongue weight for safe towing/hauling. No more scales!

Working well. As stated, great for tongue weight and especially for setting the trailer brake gain. My tow is a 38’ formula Fastech 382 with trailer and load coming in about 14,500lbs so trailer gain is critical and easy with this equipment!
Steve - 07/22/2021


This could be a great product, unfortunately the accuracy is poor and inconsistent. I was most interested in the tongue weight feature. Our travel trailer has a dry tongue weight of 680 and the vehicle has a max tongue capacity of 720. We have a weight distribution hitch but wanted better precision so I can know where to load my weight, impact of a full water tank, etc. Unfortunately I get variations of over 100Lbs when following a consistent process for weighing. I also get over 1000Lbs variation when doing the trailer weight calculation on a 6000Lbs trailer/5000Lbs vehicle combo. We did find this to be very useful when loading a Bobcat on flatbed trailer to make sure we located it properly for the right tongue weight balance. Precision was not as critical for that job. So if you are looking for ballpark numbers +/- 10% it works nicely. If you are expecting greater accuracy, this probably isn't the right solution for you.


It has to be recalibrated every time I turn off the ignition it doesn't store information. Recalibrating it is time consuming, and not very efficient although it is accurate. For my application I wouldn't purchase it again

The BetterWeigh app stores the vehicle VIN and any calibrations. If you move the BetterWeigh to another vehicle, you will have to go into Settings then to Change Vehicle and it will erase any custom calibrations. Since you have a 2004, vehicles older than 2008 or those with modified suspensions, may have to be manually calibrated instead of using the apps pre-calibrations.
-- Etrailer Expert Sierra K - 11/22/2021

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