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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

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Tongue Weight Scale
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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. Lowest 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 800-298-1624 for expert service.
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CURT Tongue Weight Scale

  • 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
  • Smart device OS requirements:
    • Apple (iOS): 10.3 or higher
    • Android: 6.0 Marshmallow and higher, Bluetooth enabled
  • Limited lifetime warranty

Note: Will not work on diesel trucks manufactured before 2004 due to OBD-II regulations.

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

Item # C51701

Installation Details C51701 Installation instructions

Customer Reviews

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

Average Customer Rating:  3.8 out of 5 stars   (83 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.

- C51701

This is a good tool to have if your pulling a trailer and don't know the load but I question its accuracy. It's fairly cheap and convenient to use and better than having nothing to estimate what load your pulling.

The Mobile tongue weight scale reads the vehicle information and lets you know the parameters outlined by the manufacturer for safe towing of your specific vehicle. It then calculates weights based on force divided by acceleration. Which will create a fairly accurate tongue weight rating.
-- Etrailer Expert Jenny N - 03/17/2022

- C51701

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

- C51701

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.

- C51701

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.

- C51701

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

- C51701

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.

- C51701

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

- C51701

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

- C51701

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.

- C51701

Calibration is not as simple or exact as it looks. You really need to go to a scale and then enter your weight. From there it's tough to be confident of the absolute numbers. Instead, look at them relative to prior readings as more of a guideline.

I researched with Curt about calibration issues with the tongue weight monitor. I found that if you have any aftermarket parts such as suspension enhancements you will need to a manual calibration. The app will walk you through the manual calibration and you will not need to remove the suspension enhancements. If a vehicle is pre-2008 then chances are higher that it will need to be manually calibrated. It can also happen if the unit is unable to find a calibration within its database.
-- Etrailer Expert Jenny N - 02/08/2022

- C51701

Works very well does the job, A nice bit of kit.

It has been a year and it is still working just fine. No problems and like i said i good bit of kit.
Brian - 04/16/2022

- C51701

Don’t like having to race down my 100’ driveway and not sure it’s really accurate at all. Would not purchase again

- C51701

Seems to work. It would be better if the weight readouts were digital not dial indicated. Haven't had a chance to use actually use out on the road towing my fifth wheel.

- C51701

Not a good fit for my equipment setup. With a GVWR 30000lb the device never gave an accurate weight. Had to resort to using the weighing scale.

- C51701

It works but not sure of the accuracy. When compared to an actual trailer tongue weight scale there is a pretty large disparity. Additionally, the set up takes some time and a lot of stopping and starting to complete. The only reason a gave it 3 stars instead of one is because it may be useful for bed load weight. I would not buy it again.

- C51701

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

- C51701

It was not consistent/reliable. One time the truck weighed 6100lbs (approx correct), the next time the truck weighed 7000lbs (not even close). Trailer tongue weight similarly unreliable. Removed it, put in on a shelf and purchased a physical scale to weigh the trailer tongue

- C51701

Never been able to get it to work corre ctly.

You mentioned that it has not worked for you and I wanted to ask if you could give more details on what it is doing?
-- Etrailer Expert Jenny N - 03/07/2022

I was never able to get it calibrated for my truck. I bought it to try and get my tongue weight correct on a boat I was going to transport. I gave up on it and have not used it since. Pretty much seems like a failure. It never once came close to the same weight reading when I was following the prompts.
-- comment by: Karson - 03/07/2022

I reached out to Curt and they had a few additional questions. Do you know what function that you were using with the scale? Can you send the VIN of your vehicle?
-- Etrailer Expert Jenny N - 03/07/2022

- C51701

I threw it away i could not get the initial setup done correctly. There were some other issue's that I did not like.

- C51701

I calibrated the tool as instructed on my smartphone and proceeded to attempt to record a baseline weight for my 2015 Toyota Sequoia. After about 1-1/2 hours and over two dozen tries, the weight being displayed was well over 3,000 pounds underweight. I didn't even bother to go forward with calculating trailer weight. I have come to the realization that this device is not quite ready for primetime. No reason why the consumer should jump through so many hoops to record an accurate weight of tow vehicle and trailer. Just as easy to hook up my rig and drive to a truck stop to weigh my vehicle and trailer. I was very excited about employing the BetterWeigh to calculate my trailer weight, but I was extremely disappointed at the complexity of the process and inconsistency of the data output from the BetterWeigh. I believe that the engineers behind the BetterWeigh need to go back to the drawing board and further develop the design before introducing it on the market. I would request a refund, but I figured that I was taking a risk on the technology from the get-go and would simply chalk up the purchase to a lesson learned. I would not recommend this product.

- C51701

works as advertised.

- C51701

Wish that I had returned this within the return period. Calibrated the scale 3 different times and could never get the same weights twice. Very difficult to calibrate, had to start and stop the truck while towing my trailer over 8 times before it would calibrate. I ended up buying a hydraulic scale that fits between the king pin and truck bed to get a consistent king pin weight. I do not recommend this product.

- C51701

Sorry but I am not impressed. It tells me my tongue weight is 940#’s. I have weighed and had it checked. It is 640#’s. I set my weight distribution up according to the instructions you provided. I found better results setting it up the old way, measuring everything by hand. The app says something along the lines of new updates coming. Nothing new since I bought it a year ago.

- C51701

Instructions on setting up for a5th not clear at all 5th hitch was great

- C51701

Overall I was impressed with the capabilities of this device. However, I was not able to use it on my tow vehicle. I have a 2015 Chevrolet Tahoe LTZ. The problem is that it has Magna-ride and automatic load leveling shocks. I have passed the device on to a friend. Hopefully he will be able to use it.

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