Payload Question (yes another one!)

I just got a 2021 Tacoma and took it to the CAT scale to see if my understanding of the weight numbers is correct before beginning to tow a camper. I couldn’t get the numbers squared.

The payload in my manual is 990 (model GRN305L-PRTSHA short-deck double-cab 4x4). There’s a sticker on the door frame indicating an additional 116 pounds of factory installed options and I’ve added a bed mat and roof railings/cross bars (guessing 30 pounds for these two items). I had a full tank of gas and I weigh 180 so I calculated available payload capacity of 664 (990 - 116 - 30 - 180) and an expected actual weight of 5,136 (5,800 GVWR less 664) but got a reading of 4,780 a difference of 356.

I read somewhere that the CAT scales were calibrated to 20 pounds per 10,000.

Is the CAT scale right or maybe they aren’t as accurate for a smaller vehicle? Or maybe something else I haven’t considered?

Thanks.

 

Go to a dump where they weigh you coming in and going out. Throw something away you know the weight of and see how it adds up?

 

Approx curb weight of your truck. Is it not 4,445?
4,445+116+30+180 = 4,771

Unless my math is bad, it seems like you're right where you should be, sitting @ 4,780.

 

There are two stickers to look at on your door frame, the tire sticker which has your payload and the yellow one for additions to subtract from the payload sticker rating. Them you deduct your add ons as you are doing above.

 

Thanks.

I kinda did that in reverse. I pulled in with 25 miles left in the tank and weighed before and after filling the tank. I put 17.9 gallons. With gas somewhere between 5.9 and 6.5 pounds per gallon (the range I found on the web depending on additives) I expected 106 to 116 - the actual difference before and after was 100 so maybe the scale was weighing light. The drive from the gas station to the scale was maybe 0.2 miles.

 

With GVWR of 5,800 and payload of 990 isn’t curb weight 4,810?

 

The tire sticker shows 990 of payload consistent with the manual.

 

Toyota's specs show the 2021 4X4, 5' box double cab SR and OR curb weight @ 4,445, with the Sport and Limited weighing in @ 4,465 and 4,505, respectively.

 

I found some additional info on CAT scales.

https://fifthwheelst.com/commercial-truck-scales-vs-portable-scales-for-weighing-rvs.html

 

More info on my question from CAT Scale


Thank you for contacting CAT Scale.


The variance of our scales is established in the National Institute of Standards and Technology Handbook (NIST) 44 Table 6. Class IIIL scales are allowed one division, or a 20 pound variance off zero for each 10,000 pounds of weight applied. Most calibration tests performed by either the State Weights and Measures or a licensed scale service company will use a minimum of 20,000 of certified test weights. In the case of a 20,000 pound test, anything beyond a 40 pound error in reading would be a failed test. In the case of CAT Scale, all of our scales are calibrated at least four times per year by a licensed service company and we require the calibration to be adjusted to zero error.


CAT Scales display and print in 20 LB increments to comply with the specifications set in NIST Handbook 44. Each of the axle weights would round up or down to the nearest 20 LB.

As an example, if your steer axle (front axle) weight is 2,612 LB the CAT Scale would register that weight as 2,620 LB. If the drive axle (rear axle) weight is 2,068 LB the CAT Scale would register that weight as 2,060 LB.


Adding 17.9 gallons of gas would weigh approximately 112 pounds. Your total difference in gross weight between the two scale tickets was 100 pounds. The approximate 12 pounds could be the result of rounding to the nearest 20 pounds on each axle.

 

When I bought my truck I drove through a country weigh station and got 4700 pounds total, I'm about 200 so the truck is about 4500 pounds. I also weighed it not only with all four wheels on the scale but front/rear separately and it added up. Didn't take weight of gas into consideration, was about half a tank as I recall. "About" is good enough for me lol.

EDIT: also was factory bumpers and no tonneau and no other cargo. If you gett aftermarket stuff add that weight in also.

 

Thanks. I'm about convinced that the numbers I got from the CAT Scale are about right. I just can't square them with what Toyota says the payload is. I'm seeing about 350 pounds more payload than Toyota if payload is GVWR less actual GVW.

 

I may be all wet, but I think an accuracy of +/-0.2% on 10,000 lbs is pretty darn good.

I s'pose you can dink about with different scales, although, the CAT reading is very good.

Don't think I' trust a landfill scale. They have motivation to weigh heavy on inbound and weigh light on outbound.

 

I agree that 0.2% is more than good enough. I haven’t been able to find a source that tells me that the scales are this accurate at 5,000 pounds. CAT does their testing at 20,000 pounds. When I see that Toyota’s payload number is not consistent with the weight I get on the CAT scale it makes me question (if payload is GVWR less GVW). Seems like either one or the other is wrong or there is something more to know about why Toyota shows the lower payload number.

 

In truth.......It doesn't matter what is wrong.

You have the weight of the empty truck (UVW), you know the GVWR of the truck. Just do a little math to subtract the UVW from the GVWR, now you have the Cargo Capacity (CC) of the truck. Done.

Find something else to fret about.

 

FYI all scales in WA state are monitored and certified by the Dept of Agriculture: https://agr.wa.gov/services/inspections-and-investigations/inspections/weights-and-measures including fuel pumps.

 

if you are worried about 356 lbs you have the wrong truck

 

Forget about any numbers you see on Toyota's website or on a spec sheet. Those numbers are for one specific truck. Every truck is different and will have different weights. GVWR stays constant within models, but since every truck is a different weight, heavier trucks with more options have less usable payload

You can approach this 2 ways. There is a sticker on the door jamb with payload from the factory. Mine is 1200 lbs



You have an additional 116 lbs of other options. Find your payload rating and subtract 116 from it.

Or you could work from GVWR.

My truck's GVWR is 5450. That means that my truck actually weighed 4250 when it was built. 5450-1200= 4250. But I have a cap on my truck that weighs 180 lbs meaning my trucks actual payload is closer to 1000 lbs.

BTW, I've actually weighed my truck and the numbers match up pretty darn close to the numbers printed on the door jamb.



Find your trucks GVWR and subtract your trucks actual weight( 4780) from it to determine your available payload. Remember, the 4780 includes YOUR weight too. Working off GVWR is usually more accurate since the payload sticker doesn't include the driver or any tools, recovery gear, accessories, modifications, or other items kept in the truck.

You didn't list the printed payload anywhere, that is important info. It appears to me that your trucks actual weight, 4780, subtracted from payload is going to give you 1020 lbs payload. And since you weigh 180 if you add 180 lbs back to 1020 you come up with the same 1200 lbs payload as my truck. Which seems about right. I'm betting your printed payload is around 1300 lbs. Then the additional 116 would get you back near 1200.

 

This is odd to me too

GVWR: 5600 lbs
GAWR: front 2940 lbs, rear 3280 lbs
So that’s saying I can have more weight on one of the axles than the other, ok

but my door states 990 lbs of cargo capacity
Then when I bought the truck I have the title that said 4326 lbs
21 gallons of gas is 133 lbs
5600 - 4326 - 133 = 1141 lbs
1141 - 990 = 151 lbs difference
So could oil, wiper fluid, etc possibly weigh that much? I’m guess the gas has to be more than half the fluid weight. It seems the door has ~100 lbs of margin built into it

anyone have any guesses?
Of course I could go weigh my truck but then there’s a debate if unsprung weight really affects payload like heavier tires or lighter wheels

was hoping maybe someone else has an estimate of what the truck with fluids weighs over the number on their title

 

Toyota specs says your curb weight should be 4495lbs. Based off your payload of 990lbs your actual curb weight (because of added options) should be about 4610lbs. Your truck does not weigh 4326lbs like listed on the title.