Know your Weight Impact on Vehicle and CT GVM - an awareness issue

[Beachman]

I understand weights when you talk about the car or trailer as separate things, but I’m a bit confused by the Kerb or Tare Weight and GVM when you combine car & trailer. For example when we go away for the week camping I know my 105 Cruiser is on it’s limits (before tailer is attached) and the trailer would weight about 700kgs fully loaded (it’s braked and registered for just over 1000kgs)

So by themselves they are legal, but are you saying once I hook the trailer up, I’m now too heavy?

[Mace]

You're only too heavy if the towball weight, which must be added to the vehicle laden mass, takes you over the vehicle GVM.

The trailer weight must be added to the laden vehicle weight to come up with a GVCM Gross Vehicle combination mass. Your cruiser will have an all up GVCM capacity far in excess of your current vehicle pus camper trailer mass, ie a cruiser GVM is say 3300 kg, plus a 3000 kg van, the GVCM weight for that combo is 6300kg, yours might weigh 3300 kg plus 1200 kg. Total  allowable Maximum GVCM for a cruiser and caravan would be in the order of 6500kg.

clear as mud?

http://www.racq.com.au/motoring/driving/towing/trailer__and__tow_vehicle_specifications_explained

 

[Barry G]

What I think most find frustrating is that it is becoming increasingly difficult to find a vehicle to purchase to do what we all consider reasonable in a legal manner.
While there are an ever increasing number of us heading out there with our homes in tow, we are, apparently, still regarded as such an insignificant proportion of the market that the vehicles we need are not built and marketed, at least by the 'usual suspects'.
A classic case of 'market failure'.  And an opportunity for some of the newcomers - Mahindra, for example?

[doc evil]

Maybe your 4wd club should revise their convoy procedures.  When someone in my club gets on the radio and says they are stopping, everyone stops.

You don't really want to be around whilst I'm having a dump.........

[ATC]

I am yet to hear of anyone who has been pulled over by the scalies and done for being over gcm. Yep, plenty of stories of ...'mates of a a mates, uncles cousins, gay lovers, sister apparently got done and was sentenced to the electric chair' type of stories.

Most people are over by not much. If there is a bad accident and they decide to weight your combination, then you and your mrs is not going to  sitting in the truck. That's about 150kgs in our situation.

Really, FFS there is more to worry about than that.

If the insurance company was really that inclined to 'not pay' then I'm sure they could find something not roadworthy with almost any car on the road.

Thankfully it wasn't an insurance company or the scalies.

A mate and I were out on a tour of outback NSW, and his truck started to overheat and do all the usual stuff that misbehaving vehicles do.

As it had roadside assist he call that and they arranged for a flatbead to come and retreive him and take it to a regional repair centre.

At the regional repair centre they promptly weighed the truck and then made a fuss over warranty, they also took a lot of pictures as their evidence.
Keep in mind that he wasn't claiming about suspension, rather the gearbox & transfer case.
Things that should be rated to cope with the GCM, not just the GVM.

In his case the vehicle has a GVM of about 3300KG, and a GVM of 6500KG (somewhere around these numbers).
They are still arguing.

In my case I claimed that the suspension in the new BT-50 is crap and has collapsed with only 50% of the payload being carried, and by the time you get to 100% of the payload you're running on bumpstops.

The dealer weighed the truck under order from Mazda.
I knew this was happening, and I'd already checked the weight / axle loading myself by taking it to a weighbridge.

ATC

[ATC]

I require all people on our 4wd club trips to carry 2 forms of lifting a vehicle..........

One of the few thing I got from the theory section of the 4wd Club course that I went to was the "Carry a Bottle Jack".

I have 4 different jacks (factory jack, 6000kg bottle jack, Hi-Lift, exhaust jack) haven't had to use them, and don't carry them all, jsut what suite the terrain here I'm going.

Was in an ARB shop one day and saw a Hi-Lift jack with a massive bow in it. They are generally only rated to 1000kg.
That's why I carry the 6000kg bottle jack.

Ironically the reason that I ignore most of what the old bloke at the 4WD club was talking about in the theory section was when he started talking about is GU Patrol is approx +3200KG just for driving around tow.
And that he doesn't see a problem with it, as it was designed based on a light truck chassie / running gear & engine.

Me I now what my truck weights, as when I add something to it I get it weighed, only costs $25 - cheap insurance.

ATC

[Symon]

Ironically the reason that I ignore most of what the old bloke at the 4WD club was talking about in the theory section was when he started talking about is GU Patrol is approx +3200KG just for driving around tow.
And that he doesn't see a problem with it, as it was designed based on a light truck chassie / running gear & engine.

My landcruiser has a steel tray, steel toolboxes on the back, a PTO winch on the front, and a steel bull bar.  With full fuel tanks and my fat arse sitting in it, it tips the scales at 3200kg.  It isn't hard to get up to those kind of weights.  Hence the reason why I got a vehicle with the GVM upgrade, so I can go up to 3780kg instead of the stock 3300kg.

[chookduck]

I understand weights when you talk about the car or trailer as separate things, but I’m a bit confused by the Kerb or Tare Weight and GVM when you combine car & trailer. For example when we go away for the week camping I know my 105 Cruiser is on it’s limits (before tailer is attached) and the trailer would weight about 700kgs fully loaded (it’s braked and registered for just over 1000kgs)

So by themselves they are legal, but are you saying once I hook the trailer up, I’m now too heavy?

Thanks to all who have contributed to this thread. 

As I stated in my opening entry I thought, along with one of the Forum Moderators,  it was a good idea to 'get this in the open' as an awareness thread. I do not really care that much what people load into their vehicles; however, they should be aware of the impact on GVM and any consequences resulting from possible overloading.

Hopefully Beachman has gained some info he can use.  Hopefully some of those 850 or so 'viewers' who have not posted any comments have also gained some insights.

The bigger challenge will be if accessory outlets and vehicle sales persons actually start thinking/doing/saying "if you want all of those accessories added, you will most likely require a GVM upgrade to remain legal."  I live in hope and probably dreamworld!!!

So, with today's modern vehicles, I see the options of dual cab utes and some of the 'plainer' variety - Land Rover Defenders for example (also note here that Land Rover Defender Kerb weights are defined as "Minimum kerb weight = Unladen weight + full tank and 75kg driver") - as providing at least some buyers the option of larger usable payloads around, or greater than, 900kg or so without a GVM upgrade.

Any Swaggers out there want to comment on legal GVM upgrade processes they have undergone?

[Mace]

 I believe austastar purchased his defender for carrying capacity reasons as well as it being a vehicle that he liked. It could carry his slip on camper well within limits.

He may be close to 75 kg too! 

Smart thinking.

[achjimmy]

Manufacturers will do SFA about this until it becomes policed by legislation. As I said before most fourbies have a pathetic GVM.

When I got my cruiser upgraded, the guy said he used to do 3-5 upgrades a year. Since 2012 he has been doing 3-5 a month including a heap for the NSW government. I strongly believe the governments will click on to this one day and start checking, but they will also have to come up with something to allow older vehicles to be complianced. Currently in NSW you can not upgrade a GVM after initial registration and they do not acknowledge "state" based GVMs from other states.

Aftermarket suppliers like ARB will have to wake up.  Currently the highest GVM upgrade ARB will do to a 200 cruiser is 3580kg (extra 280kg) My cruiser with bull bar, winch (dyneema) rear seats removed (-40kg) ply floor, fridge slide, full tanks (140l)and cargo barrier is 3000kg ! How many catalog special (steps, drawers, fridge, rack, rear bar, LR tank as well) 200s running around do you reckon comply with a family of 4 onboard? Little alone towing.

Fortunately Lovells do a 3800kg upgrade (+500kg) but you do get raped for it. Even with this you need to be cautious.

As above driving sensibly to the conditions is the key, and not just offroad.

[Metters]

So, with today's modern vehicles, I see the options of dual cab utes and some of the 'plainer' variety - Land Rover Defenders for example  as providing at least some buyers the option of larger usable payloads around, or greater than, 900kg or so without a GVM upgrade.

Unfortunately there is one trap that many fall into with the carrying capacity of dual cabs and that is the manufacturer expects you to load the 5 seats to the maximum if you intend taking the car up to GVM.  I have seen plenty with heavier springs or air bags because the rear end is overloaded but the cabin contains two light weight adults and one or two featherweight kids in the back seat.  To get them up to GVM and still look level, you need close to half a ton of people in the front.

[doc evil]

I had the GVM upgrade done on my Patrol after I had owned it for 3 years (from new).

As I had just shifted from Vic to WA, and the GVM upgrade was done whilst unreg'd (being transfered to WA reg). No issues there.

Cost was incorporated into the ute conversion (I think it was around $1700).

Issues that arose........

I had a 3 inch lift, max suspension lift on a GVM was 2 inch, so new suspension was bought (expense).
Tyres, the tyres I had at the time (Procomp extreme all terrains, 285x75x16) were deemed excessively above the load rating the vehicle was being examined for (3700kg). So I had to borrow some standard bridgestone duelers that were OE. (Non expense).
Chassis plating and top spring hat strut. This was also engineered, but was part of the tray inspection. (built in cost of the conversion).

The down side is it's only WA recognised as well however, I have been told (in writing) by my insurance co. that they realise this and my insurance is still covered outside of WA.
The biggest pain will be if I decide to move interstate or sell the vehicle interstate........

[Mace]

Tyres, the tyres I had at the time (Procomp extreme all terrains, 285x75x16) were deemed excessively above the load rating the vehicle was being examined for (3700kg). So I had to borrow some standard bridgestone duelers that were OE. (Non expense).

Interested as to why over rated tyres were an issue?

[chookduck]

Some interesting FAQs here from one company regarding GVM and GVM upgrades.

http://www.statewide4x4.com.au/faq.aspx

[ATC]

My landcruiser has a steel tray, steel toolboxes on the back, a PTO winch on the front, and a steel bull bar.  With full fuel tanks and my fat arse sitting in it, it tips the scales at 3200kg.  It isn't hard to get up to those kind of weights.  Hence the reason why I got a vehicle with the GVM upgrade, so I can go up to 3780kg instead of the stock 3300kg.

Symon,
My issue with the training course I did was the "Dickhead" trainer telling a bunch of new 4wd'ers that massively, overloading was routine and OK.

This is from an organization that is registered o provide 4wd driver training.

Got to put my truck on a diet, getting a few ideas from this thread.

Perhaps a companion thread on weight saving ideas.
Eg currently I carry a draw full of tools, got too park 1/2 to 2/3 of these in the garage and bring a smaller functional set..

ATC

[doc evil]

Interested as to why over rated tyres were an issue?

If I recall, the procomps were load rated at 1500kg, therefore the tyres are rated at 6000kg combined. Vehicle upgrade was 3700kg so almost half what the tryes are rated at.
The original equipment tyres rating (if I remember) was around 1100kg, so a total of 4400kg which is closer to the 3700kg.

[Spada]

So, anyony know wro in Brisbane cane do GVM upgrade certification.

I've already done all the suspension upgrades, just need to get it certified ?

[weeds]

So, anyony know wro in Brisbane cane do GVM upgrade certification.

I've already done all the suspension upgrades, just need to get it certified ?

a mate of mine is a certifier (I assume he can do GVM upgrades) and can fit blue plates.......although he follows all the rules to a tee and is very particular. I can pass on his details but you might want to also have a chat to other certifiers as well

[chookduck]

I understand weights when you talk about the car or trailer as separate things, but I’m a bit confused by the Kerb or Tare Weight and GVM when you combine car & trailer. For example when we go away for the week camping I know my 105 Cruiser is on it’s limits (before tailer is attached) and the trailer would weight about 700kgs fully loaded (it’s braked and registered for just over 1000kgs)

So by themselves they are legal, but are you saying once I hook the trailer up, I’m now too heavy?

So, continuing the 'awareness' theme of this thread and doing some research, I will attempt to answer Beachman's query, that Mace provided an answer and a link, with some definitions and examples and the impact of GVM upgrades.  Post edited to not make reference to a particular vehicle

The issue here is what is known as Gross Combined Mass or GCM.

GCM is the most weight that your vehicle is allowed to tow and carry on your vehicle combined. That is, the combination of your vehicles GVM and the gross weight of whatever is towed.  For example a vehicle has a GVM of 3350kg and Gross Trailer Weight (braked) of 3500kg and a GCM of 6850kg.  In this case the GCM is simply the addition of the GVM and Gross Trailer Weight.  Not all vehicles are like this so you should look up your respective vehicle specifications.

I don't think, aside from major and probably cost prohibitive modification, you cannot increase the overall GCM or the maximum towing capacity over the manufacturers specifications; however, this could be State dependent. By increasing the GVM of your vehicle you subsequently decrease the Gross Trailer Weight by the same amount.

Using the same vehicle figures again, if you were towing a 2500kg caravan with a ball weight of approx 250kg and the vehicle was loaded up to its maximum GVM of 3350kg (inc the 250 kg ball weight) then your combined mass would be:

GVM 3350kg + Caravan 2500kg = 5850kg

As you can see, you still have another 1000kg you could tow (assuming same 250 kg ball weight as any increase to this would put you over GVM) before you reach the vehicle's maximum GCM of 6850kg.

So what is the  impact of a GVM Upgrade?

Now remember, the GCM for the vehicle above was calculated as 6850kg and cannot be changed.  By having a GVM Upgrade fitted and increasing the GVM of the vehicle from say 3350kg to 3800kg, your Gross Trailer Weight (braked) is now decreased by the same amount your GVM is increased.  So, looking at the original formula of:  GVM + Gross Trailer Weight (braked) = GCM, we can now turn this around to calculate the new Gross Trailer Weight (braked) as:   GCM - GVM = Gross Trailer Weight (braked), or 6850 kg - 3800kg (GVM Upgrade) = 3050kg in this case.  So our new Gross Trailer Weight (braked) has reduced 450 kg from 3500 kg to 3050 kg, the same amount that the GVM Upgrade was increased (3800 kg - 3350 kg).

However, ensure you look up your vehicle's specifications as determining GVM and GCM vary between manufacturers.

As Mace said above:  "clear as mud".

[achjimmy]

So, continuing the 'awareness' theme of this thread and doing some research, I will attempt to answer Beachman's query, that Mace provided an answer and a link, with some definitions and real examples (weights taken from Toyota website) and the impact of GVM upgrades. 

The issue here is what is known as Gross Combined Mass or GCM.

GCM is the most weight that your vehicle is allowed to tow and carry on your vehicle combined. That is, the combination of your vehicles GVM and the gross weight of whatever is towed.  For example the Toyota GXL Turbo Diesel 200 Series has a GVM of 3350kg and Gross Trailer Weight (braked) of 3500kg.  We add these together to determine the vehicle's GCM of 6850kg.

I don't thick, aside from major and probably cost prohibitive modification, you cannot increase the overall GCM or the maximum towing capacity over the manufacturers specifications. By increasing the GVM of your vehicle you subsesquently decrease the Gross Trailer Weight by the same amount.

Using the same 200 Series figures again, if you were towing a 2500kg caravan with a ball weight of approx 250kg and the 200 Series Landcruiser was loaded up to its maximum GVM of 3350kg (inc the 250 kg ball weight) then your combined mass would be:

GVM 3350kg + Caravan 2500kg = 5850kg

As you can see, you still have another 1000kg you could tow (assuming same 250 kg ball weight as any increase to this would put you over GVM) before you reach the manufacturers maximum GCM of 6850kg.

So what is the  impact of a GVM Upgrade?

Now remember, the GCM for the 200 Series was calculated as 6850kg and cannot be changed.  By having a GVM Upgrade fitted and increasing the GVM of the 200 Series Landcruiser from say 3350kg to 3800kg, your Gross Trailer Weight (braked) is now decreased by the same amount your GVM is increased.  So, looking at the original formula of:  GVM + Gross Trailer Weight (braked) = GCM, we can now turn this around to calculate the new Gross Trailer Weight (braked) as:   GCM - GVM = Gross Trailer Weight (braked), or 6850 kg - 3800kg (GVM Upgrade) = 3050kg in this case.  So our new Gross Trailer Weight (braked) has reduced 450 kg from 3500 kg to 3050 kg, the same amount that the GVM Upgrade was increased (3800 kg - 3350 kg).

As Mace said above:  "clear as mud".

Chookduck Iam not going to go into all here as I couldn't be arsed. But on lcool the GVM/GCM debate has raged and not been concluded. There is not a clearly defined GCM listed for the 200 (or was) but is worked out as above and iirc their was a member who had information to the contrary from Toyota. So the GCM  of GVM  upgraded 200's is a grey area, bit like the clearance light issue as well.

FYI both the GVM and towing capacity is able to be upgraded, and again on lcool someone posted a compliance plate that listed both increased 3800kg each iirc.

Edit Seems in NSW the towing capacity can't be increased anymore.

[achjimmy]

Below is the compressive list of vehicle specs out out by the caravan mob, it's complied for manufacturers and transport I think. This is the Toyota page from 2012.
So on my door I have a compliance plate that states GVM 3800kg and next to it I have the Toyota towing plate stating 3500 towing mass 350kg ball. No GCM pretty straight forward in my eyes  in saying that I don't tow anything over 2t but wanted the GVM to make the vehicle legal.

[chookduck]

Chookduck Iam not going to go into all here as I couldn't be arsed. But on lcool the GVM/GCM debate has raged and not been concluded. There is not a clearly defined GCM listed for the 200 (or was) but is worked out as above and iirc their was a member who had information to the contrary from Toyota. So the GCM  of GVM  upgraded 200's is a grey area, bit like the clearance light issue as well.

FYI both the GVM and towing capacity is able to be upgraded, and again on lcool someone posted a compliance plate that listed both increased 3800kg each iirc.

Edit Seems in NSW the towing capacity can't be increased anymore.

Thanks achjimmy.  I only used the 200 Series as an example. I could have just said Vehicle XYZ.  It was more the math process i was interested in.

I'll change the post.

[achjimmy]

Thanks achjimmy.  I only used the 200 Series as an example. I could have just said Vehicle XYZ.  It was more the math process i was interested in.

I'll change the post.

No worries Chook. It's a bit unusual the 200 not having a GCM.

[chookduck]

No worries Chook. It's a bit unusual the 200 not having a GCM.

And no where near as complicated as some dual cab 4WD utes - take the Navara for instance and have a look at the specs page at http://www.nissan.com.au/~/media/Files/Brochures/Specifications/D40-Navara-Specification.ashx

[jr]

Pretty sure light vehicles DONT  have a GCM and thats part of the GVM upgrade problem

Only state GVM and max towing capacity
To be certified properly (braking ability being key concern) max towing needs to be reduced as well as GVM increased
GVM can only be upgraded to next major component constraint level, ie max axle weights, many manufacturers dont even quote this.