Payload limits RAM 1500 tow capacity

If you’re buying a new V8-powered RAM 1500 with plans to tow a trailer up to its maximum 4500kg, be prepared to go on a diet because there’s a good chance that your rig will be overweight once you hop aboard.

To not exceed the maximum Gross Combined Mass (which is the maximum legal weight for vehicle and trailer combined, as specified by the manufacturer) while taking full advantage of the RAM 1500 Laramie’s maximum 4500kg tow capacity, you will have just 87kg of payload remaining.

Payload includes any occupants, including the driver, according to RAM Trucks Australia.

So if for example you weigh 100kg, your rig will be 13kg overloaded as soon as you climb onto the RAM’s side steps.

That’s for the RAM 1500 Laramie with the shorter 3.92:1 differential ratios.

With the optional taller 3.21:1 diffs, if you use all of its 3500kg maximum towing capacity you will still have only 111kg payload left before reaching the 6261kg GCM maximum.

That would be enough payload to include most drivers and their travelling knick-knacks but for recreational caravanners, who tend to travel in pairs, it's likely to fall short.

That issue might be resolved with the base model, the RAM 1500 Express, which has the best payload of the range when towing up to its maximum 4500kg.

Under the same scenario the 1500 Express can take a 132kg payload, which just might be sufficient for a compact, lean couple who eat like birds and pack light.

If you tow a lighter trailer you might even be able to release a notch on the belt and not fall foul of GCM — but you might strike other weighty problems.

You might exceed the RAM’s a relatively low payload maximum (800kg for Laramie, 845kg for Express).

That’s because, in many cases around 10 per cent of the trailer’s weight becomes vehicle payload once the trailer is hitched up (that is, the weight of the trailer on the towball).

A 3500kg trailer would for example typically impose 350kg of that on the towball, when fully loaded. That means you could have a 450kg payload capacity remaining in the Laramie (800kg-350kg).

While RAM kerb weights includes a full tank of fuel (98 litres for Laramie and an impressive 121 litres for Express), unlike some other manufacturers it doesn't include a nominal weight for the driver.

That means you have to account for the full driver’s weight in payload calculations before considering any other fixed items such as a bullbar, driving lights, UHF or incidental items such as a car fridge, generator or 4WD recovery equipment.

Or, in the RAM Laramie’s case, when towing 4500kg, payload items such as clothes, a toll tag, mobile phone, house keys or loose change.

While the RAM 1500’s payload capacity is more adversely affected than competitors when towing, it's not the only ute to encounter weight problems when towing, as we outlined here.

The Ford Ranger Wildtrak, for example, will exceed its 6000kg GCM if it has more than a 250kg payload when towing its 3500kg permitted maximum.

Shorter, lower and lighter than the existing RAM 2500 utility, the RAM 1500 tips the scales at 2420kg, and is powered by a 5.7-litre HEMI V8 petrol engine.

It's on sale in Australia now, priced from $79,950.