Axle Weight Calculation Spreadsheet

[NTBenny]

All,

I’ve had a few spare hours recently and thought I’d create a spreadsheet that enables people to calculate their axles weights when additional loads such as tow ball, cargo area and passengers are being added to their car. This spreadsheet was designed to utilise the information previously provided by OJ and Mundy 55 in the below linked threads. I also completed measurements on a certified weighbridge to determine how front and rear passengers affect axle weights. To enable the spreadsheet to work you must populate the data in the orange and yellow cells. All other cells have been locked to prevent inadvertent changes being made that could prevent the spreadsheet from operating correctly. If the data entered results in the maximum OEM weights being exceeded cells F16,17,19 & 20 will turn red advising of this condition.

Note: The figures currently populating the orange cells are LWB Pajero specific. These should only need changing if you are using the spreadsheet for a different type of vehicle. The front and rear weights in cells B17 and B18 are from my vehicle last weekend on the weighbridge.

I hope this comes in handy for others. If anyone can see any issues with the spreadsheet then please let me know and I can correct the errors.

Finally I’d like to thank OJ for checking my work and providing feedback on formatting etc.

https://www2.pajeroclub.com.au/forum/showthread.php?t=53058

https://www2.pajeroclub.com.au/forum/showthread.php?t=53023&highlight=axle+weight

Regards,

Benny

[Onslow]

Nice work Benny. If your formulas are correct I'm just within my limits each time I load up to go away.....gotta be happy with that!

[NTBenny]

Hi Onslow,

The formulas are based on what Mundy 55 posted in the linked threads. I also had OJ cast his eye over the spreadsheet so hopefully all is correct.

Would be great to incorporate the use of a WDH somewhere but I'm not smart enough to figure that one out.

Benny.

[Pajshomoneroguntero]

Awesome. Thanks for putting in the effort

[dhula]

Like your work


If me and my mrs hop in the front of your car with nothing else in it, we make the front axle weight turn red, guess we must be FHCE's

[miniyazz]

Great job NTBenny.

Does anyone know how heavy the rear (3rd) row of seats are in the Pajero? I read somewhere the middle row are each around 40/60kg single/double but I expect the third row of seats is somewhat lighter.

Really I'm trying to calculate how heavy duty my rear suspension needs to be so if anyone has weighbridge figures for the the rear axle in a (near as) stock car (unlikely on this forum!) that would be very helpful!

My best calculations so far for my 2016 GLX5 NX, with assistance from this spreadsheet:
Front:
1) ARB steel bullbar ~80kg
2) Warn Tabor 10k winch + steel cable - 40.4kg
3) Twin spotlights and 22" light bar, harness etc ~15kg
4) BushSkinz intercooler/sump plates 4mm - 17kg

Central (ish):
5) Rhino-Rack Pioneer SX full length alloy roof rack - 25kg
6) 5m 0AWG cable ~2.5kg
7) Transmission/transfer case Boo's bash plates 3mm - 16kg
8) Boo's bash plates fuel tank guard - 18kg

Rear:
9) -Rear seats - ~35kg
10) 60L King's Fridge - 22.5kg
11) Second battery + charger - ~35kg
12) Recovery gear - ~20kg
13) Boo's rear bumper guard - 12kg

Weights checked prior to fitting 7,8,13 - front axle 1255kg no people, rear axle 1220kg no people, and with half a tank of fuel.

1 700mm forward of front axle (80kg => f100kg r-20kg)
2,3 800mm forward of front axle (55.5kg => f71.5kg r-16kg)
4 300mm forward of front axle (17kg => f18.8kg r-1.8kg)
5,6,8 estimated 40/60 f/r (45.5kg => f18.2kg r27.3kg)
7 estimated 70/30 f/r (16kg => f11.2kg r4.8kg)
10 300mm over rear axle (22.5kg => f-2.4kg, r24.9kg)
9,11,12 700mm behind rear axle (20kg => f-5kg r25kg)
13 800mm behind rear axle (12kg => f-3.5kg r15.5kg)

Giving a grand total of approximately 208.8kg extra on the front and 59.7kg extra in the rear (over stock), which at least reassures me that the heavy duty '100-300kg' rear payload springs/shocks are probably the right choice..

With regards to my axle weights, I am ok with a full tank of fuel as long as it's basically only me in the front of the car! However, if I added for example the 70kg Titan rear shelves I could allow myself a tiny 40kg front passenger (I am only around 65kg myself) - I do find the front axle rating a little stingy . I suppose if I load it up with some baggage for a trip this might tip me into managing a more normal-sized front passenger and I have almost 350kg payload remaining after all the above added weight + rear drawers + a full tank of fuel + myself (but no passengers) which is still a decent amount!

I know you are using the latest figures but it might be worth mentioning that the allowable weights are significantly lower for the older Pajeros.

[old Jack]

Great job NTBenny.

Does anyone know how heavy the rear (3rd) row of seats are in the Pajero? I read somewhere the middle row are each around 40/60kg single/double but I expect the third row of seats is somewhat lighter.

Really I'm trying to calculate how heavy duty my rear suspension needs to be so if anyone has weighbridge figures for the the rear axle in a (near as) stock car (unlikely on this forum!) that would be very helpful!


Giving a grand total of approximately 195.4kg extra on the front and 67.9kg extra in the rear (over stock), which at least reassures me that the heavy duty '100-300kg' rear payload springs/shocks are probably the right choice..

With regards to my axle weights, I am ok with a full tank of fuel as long as it's basically only me in the front of the car! However, if I added for example the 70kg Titan rear shelves I could allow myself a tiny 48kg front passenger (I am only around 65kg myself) - I do find the front axle rating a little stingy . I suppose if I load it up with some baggage for a trip this might tip me into managing a more normal-sized front passenger and I have almost 350kg payload remaining after all the above added weight + rear drawers + a full tank of fuel + myself (but no passengers) which is still a decent amount!

I know you are using the latest figures but it might be worth mentioning that the allowable weights are significantly lower for the older Pajeros.

Yes you do have a "nose heavy" Pajero, but so will everyone else that has a steel bar, winch etc. Good news is as you load up the rear cargo area, apply a towball load and load up the rear seat, the weight transfer will relieve some of the load off the front axle.

What amazes me is people are unaware of the weight transfer off the rear axle and onto the front axle when fitting accessories forward of the front axle, the same people also fail to understand why they should be running higher front tyre pressures than rear when unloaded, but are more than happy to increase the rear tyre pressures once rear axle loads are increased.

Major problem with the IRS is that once you apply 300-500kg of extra load onto the rear axle the rear wheel alignment can change substantially and cause rapid tyre wear on the inner edges of the rear tyres.


I checked NT Benny's V7 worksheet last night and found a small problem, I have emailed him so hopefully he will correct it and post V8.

OJ.

[NTBenny]

Thanks OJ. I've updated the spreadsheet which is now Ver 9 in the original post.

Benny.

[Pushbike]

Thanks Benny,
I've appended your email to the spreadsheet as a user guide. Haven't got my head around what this all means yet but by all accounts your work should be very useful in my future.
Again thanks.

[NTBenny]

Thanks. I looked on the web for calculation tools but most seem tailored to trucks etc. I thought I might fill my time with using the information already here and design something that might be useful to forum members. It's very interesting to see how much extra load is taken by the rear axle when attaching a trailer and loading our cars.

Benny.

[Hill]

Useful tool

Thanks for posting

What model spec and accessories are included in reaching kerb weight of 2.5T
An NT Diesel Auto GLX has a kerb weight of 2273kg. Reference http://australiancar.reviews/_pdfs/M...ons_200812.pdf

Hill

[NTBenny]

My signature is probably a good indication of what my Paj is carrying. I'm only running the intercooler and sump bash plates at this stage. Plus about 35kgs of recovery gear in the rear seat well. Also includes a full tank of fuel.

Benny.

[miniyazz]

Useful tool

Thanks for posting

What model spec and accessories are included in reaching kerb weight of 2.5T
An NT Diesel Auto GLX has a kerb weight of 2273kg. Reference http://australiancar.reviews/_pdfs/M...ons_200812.pdf

Hill

Mine is 25kg under (if it had been a full tank of fuel, more like 20kg over) 2.5T (NX GLX, kerb weight 2255kg) with the below accessories, and also light truck tyres on 17" rims:

Front:
1) ARB steel bullbar ~80kg
2) Warn Tabor 10k winch + steel cable - 40.4kg
3) Twin spotlights and 22" light bar, harness etc ~15kg
4) BushSkinz intercooler/sump plates 4mm - 17kg

Central (ish):
5) Rhino-Rack Pioneer SX full length alloy roof rack - 25kg
6) 5m 0AWG cable ~2.5kg

Rear:
9) -Rear seats - ~35kg
10) 60L King's Fridge - 22.5kg
11) Second battery + charger - ~35kg
12) Recovery gear - ~20kg

In fact after running the numbers that suggests I have slightly underestimated some of my accessories' weights - it adds up to 2477.5kg. That's not too far out though, and is probably partly explained by the unsprung added tyre weight which I had ignored due to worrying more about suspension loading.

[Hill]

Miniyazz


Thanks for posting. I've also started adding up additional weight. Kerb eight from MM should include a full tank of fuel.


Must admit I forgot to add cabling for 2x Anderson etc.

Hill

PS Dicky seats are around 35kg

[miniyazz]

Miniyazz


Thanks for posting. I've also started adding up additional weight. Kerb eight from MM should include a full tank of fuel.


Must admit I forgot to add cabling for 2x Anderson etc.

Hill

PS Dicky seats are around 35kg

Nice one thanks