Calculate D-Value for Towing Equipment on the Truck | Trailer
D-Value is one of the most understood calculations in the truck and trailer industry. We will try and make it easy with a little technology and science.
First, let’s look at the rating on the coupling or pintle hook. We discovered this rating bears no relationship to your tow vehicle nor your trailer.
However, combination pintle hook rating has a direct relationship to the tow ball. Tow balls are tested to a very specific rating according to AS4177.2
If you click on this link, it will open in another tab for quick reference. https://www.couplemate.com.au/trailer-parts/couplings-and-parts-trailer-parts/pintle-ring-coupling
We are now looking at the CM255, a Pintle Ring Coupling rated at 6t. Soon you will be like me, asking what the 6t rating refers to.
New Automatic Calculation Methods
Customers unsure of how to calculate D-Value methods should go to the form calculation then enter in your truck GVM and the Trailer ATM.
The calculation field equation below has been inserted into a radio button and shows how to auto calculate d-value.
Once you have the calculated based in the form of a D-Value then you can select the towing product?
Products with NO D-Value are illegal to be used on the road.
D-Value = 9.81 x (Tow Vehicle GVM x Trailer ATM) / (Tow Vehicle GVM + Trailer ATM)
If you do the equation, a 12t truck tow an 8t trailer has a D-Value of 47Kn. Click the D-Value Sheet here for confirmation
So now we are all aware of how easy it is to select the correct pintle hook, can you tell me the relevance of the rating stamped on a product?