Colarado v Navara

[Dion]

The weight of the towed vehicle DOES affect the weight of the vehicle towing it, because you're supposed to add the ball weight of the towed vehicle to the CARRIED weight of the towing vehicle.

It does, yes, but that wasn't the question. The question was, does the payload affect the towing capacity, not does the ball weight affect the payload.

Nissan treat an increase in ball weight as a reduction in GVM, rather than treating it as a part of the payload. From the D40 (4x4 DC) spec sheet, a 150kg ball load does not affect GVM at all. A 300kg ball weight decreases the GVM by 200kg. You can't always assume that the ball weight of the trailer is always equal to 10% of the trailer's mass - there are trailers that only recommend a ball weight 5-7% of trailer mass. 5% of 3000kg doesn't affect the GVM at all - so you can carry the full 776kg (DC ST-X Auto) of people, camping gear etc you're alloted.

As far as Colorado vs Navara is concerned - the Colorado has a much lighter kerb weight (must be all those interior goodies), but a similar GVM - so you can carry more onboard. Holden don't publish specs online regarding max ball weight, so for all the consumer knows the opposite might apply to what the salesman said.

 

[Old.Tony]

I think if you fully load a D40 - and my documentation says a new DC D40 can take 810kg - then there's NO spare capacity for ANY ball weight, so you shouldn't be allowed to tow. That's the point I was trying to make, although not as well as I might have.

I think Nissan's exercise in GVM, ball weights etc is just a mathematically different way of looking at the same thing, perhaps in an attempt to make it more understandable.

5% of 3000kg is still 150kg, and that is (should be) significant enough to add into the GVM. It's my opinion only - and I know I'm not the one that writes the laws relating to this sort of thing - but it's the way I would do it.

The kerb weight of the D40 isn't all that much higher than the Colorado (stock). It's 1995kg, according to my pamphlet (meaning I've got 505Kg of extras carried in mine!) so it's 123Kg lighter. With a GVM of 2900kg, it should be able to carry 1028kg, where the Navara's 2980kg GVM and 1995Kg kerb weight should allow it to carry 985kg. All figures don't include fuel, driver etc. This means there's a 28kg allowance in the Colorado for fuel and driver (1028 - 1000), whereas in the Navara it's 985-810 = 175kg. Nissan's being realistic, I think, and Holden are just pushing figures to make it seem like a better deal.

Put 80 litres of diesel and an 80kg driver in both cars. The D40 can still take its claimed 810Kg (80+80+1995+810 = 2965 < 2980) - so Nissan's claims are valid, but the Colorado would become overloaded (80+80+1872+1000 = 3032), so you'd have to reduce the 1000kg payload to 865kg. Alternatively, you could try using only 5 litres of fuel and a 4 year old boy to be able to actually use its claimed capacity.

I think Nissan's "Maximum ball weight" is based on that 10% rule, too, which as you point out isn't always the case. I think 10% is a reasonable guide, particularly for single-axle trailers, but double-axle or higher should be fine with less, since they're inherently more stable.

In the end, I'm just glad I didn't go the Colorado. I was tempted, as my Holden Commodore was a brilliant vehicle, and I had reasoned that the Colorado couldn't be too bad. I chose differently, and I'm glad I did.

For the extra few kg that I could put in the back of the Colorado, I'll take the nicer things I have in my D40 and sent the rest parcel post.