Towing capacity of a vehicle

[Brad]

Hi all,
How do car manufacturers determine the towing capacity of a vehicle?
What attributes of a vehicle determine the difference in the towing capacities?

 

[Roh]

Hey Brad,
Good question, apart from the obvious things like weight, suspension, tyre size, chassis strength, I'd be interested about how they actually arrive at a specific weight.
Can't wait until someone more knowledgeable pipes up and shares some info
Roh.

 

[Burnsy]

I've been interested to know also, another factor could be brake rotor size and tow bar design or how it's mounted to chassis. I have no doubt that a vehicle with a 2.5T rating would be comfortable towing 3T as long as it has the grunt, but if it's stated I guess legally your governed!

Cheers.

 

[achjimmy]

Yeah be good to know, look at the current crop of duel cabs. The chassis on them is bugger all different to the chassis on the older duel cabs but the tow rating has been doubled. So they must be basing it on power and brakes.

 

[Matty4]

And cooling capacity

 

[coled1970]

a lot has to do with brakes, bigger brakes pull up more weight better. Same as hi performance cars, the more powerful they get, the more they weigh the bigger the brakes get.

 

[straydingo]

simple - they look at what the consumer wants and say "that will be our new capacity", and then fit brakes bigger.

Cynical, I know.....
But consider
- one ute got 100mm longer wheelbase and went up half a tonne (can't be engine)
- the Pathy gets a 2.5l with 3tonne, or 3.0l with 3.5tonne. (can't be the chassis)
- they are commonly just half tonne upgrades (why not +400 +450 +550 kg)

 

[Bank of Dad]

Or in the case of the Prado, Toyota seemed to have knocked half a tonne off the overseas Prado to protect the Landcruiser!

 

[crackacoldie]

Mostly set by marketing people, there only seems to be a couple of manufacturers that seriously look at the safety of the vehicles to set a limit, Toyota being one of them.


Oops there is my cynical side again

 

[mbr37746]

Nah @crackacoldie you're not cynical, just provocative!
That's the explanation I give at work to get away with it anyways.
I would like to know how my ml triton 2007 has a 200kg lesser towing capacity than my old mans does, his is an '09 model? 2300kg vs 2500kg?
Next question, how many van salespeople will tell you the van comes in below your towing capacity of "x" but fail to tell you that you won't be able to carry anything as it'll put your weight over. A trap for many I guess.

 

[relgate]

Nah @crackacoldie you're not cynical, just provocative!
That's the explanation I give at work to get away with it anyways.
I would like to know how my ml triton 2007 has a 200kg lesser towing capacity than my old mans does, his is an '09 model? 2300kg vs 2500kg?
Next question, how many van salespeople will tell you the van comes in below your towing capacity of "x" but fail to tell you that you won't be able to carry anything as it'll put your weight over. A trap for many I guess.

I have always found Jayco very good with asking about your towing vehicle and checking that it will manage the ATM. I guess it depends on the dealer

 

[icetechaus]

It also depends on the gearbox and diff. My old Falcon was 1600 kilos for the manual and 2100 for the auto on the same model.

 

[davemc]

We where asked this almost very place we looked what are you towing with. Which would be good for those getting close to their limit. I reply the cars not the problem we only have space for a 18-19" tops.

 

[mbr37746]

I have always found Jayco very good with asking about your towing vehicle and checking that it will manage the ATM. I guess it depends on the dealer

Hehe see, that's me again being provocative.
I do agree, jayco was good with the questions on weight, although I did have a few (other makes) at the shows last year I was not too sure on the detail in the pitch.
Sorry back to topic.....
Can a vehicle be engineered to allow more than plated capacity?

 

[crackacoldie]

I got advise from a major crash investigator when we were attending an accident with CFS, his advise was that if the trailer is in such a condition that it cannot be weighed as part if a traffic accident investigation, the name plate ATM would be assumed. To me this means if I tow a van with a 2400kg tare and 2900kg ATM witha Prado, as an example, with no load in the van, had an accident that severely damaged the van, it would be assumed that I was overloaded.

 

[Antman]

From my knowledge and everything that i have read, (and only Qld info) i don't believe that you can upgrade the plated towing capacity of a vehicle. You can however upgrade the GVM of some vehicles with certified suspension products.

Jayco was good to me when we purchased our van, asked lots of questions and made sure that we would be able to tow the ATM of the van. Wifes parents have been looking at possibly upgrading their van from a pop top to a full height van. They drive a prado - rated at 2.5tonne towing capacity. The amount of dealers that say yeah the van is in the tow limits of the car. You investigate further and yes while the van is within the limits of the tare, the ATM's are an entirely different story so you wouldn't be able to carry anything. I feel sorry for first time van purchases who are non the wiser. I believe that the industry should be better regulated.

 

[achjimmy]

From my knowledge and everything that i have read, (and only Qld info) i don't believe that you can upgrade the plated towing capacity of a vehicle. You can however upgrade the GVM of some vehicles with certified suspension products.

There was a modifier in NSW that was increasing both GVM and tow cap on landcruisers to 3800kg each. Not sure they are still doing it but they were 2-3 yrs ago.

 

[bigcol]

yes there are places in all States where you can upgrade the GMV and also the Towing Capacity

however

you can only do it to a New Vehicle, that has NOT already been Registered.
ie: go buy brand new Disco 4 (dont license it)- to get it re-engineered you need to change things (suspension, brakes and tyres) then get it authorised by nominated Engineer (see your State DoT for who can do it)
it must pass certain tests - Lane Change is 1 that I know of
once signed off, the State DoT then can License it.... in QLD and I think NSW it gets a new "mod plate" (Blue Plate) on bulkhead and chassis

in theory - I can change the GMV and Towing Capacity on my 1999 4.2 diesel Patrol by changing the brakes to ones off a 4.8L Petrol Patrol
(they are bigger) - it would give me an extra 200Kgs - however - it is not New, so I can do the Mod - but not get it re-licensed with the new figures.....

so far I only know of people doing the 200series and the Disco 4

simple -
But consider- they are commonly just half tonne upgrades (why not +400 +450 +550 kg)

they only do it in 1/2 tonne upgrades to make it simple for them........... easier to "round up" the figures

 

[achjimmy]

Yes I got a new (additional) compliance plate for the 200. Actually I recall now someone saying they will increase GVM or towing in NSW now but not both any longer, It may have been on lcool.

 

[Drewser]

Very well explained @bigcol, that is what I have read in the past. I also read that as well as brakes, tow bar, chassis strength etc the LENGTH of the chassis/ vehicle is a big consideration, which would explain in some respect the new dual cabs having a higher rating, as most are longer than their predecessors.