The smaller number is the one that ruins the trip. On a loaded flatbed, the axles carry most of the gross vehicle weight and the tow vehicle hitch carries the remainder, yet that remainder is the share that decides whether the trailer tracks straight down the interstate or starts hunting across the lane while your hands tighten on the wheel.

That split changes the loading question. Getting a car and a pile of equipment onto a deck so it looks centered is easy; distributing the weight so the axles and the hitch each carry what they were rated for is the actual job. Everything here is scoped to the Big Tex single-tire trailer manual, 2020 edition, and it assumes you have that model's own tongue-weight figure and weight ratings in front of you.

Tongue Weight Decides Sway Once GVWR Is Met

Start with the lever, because that is all a trailer is. A deck pivots on the axle group. Weight ahead of the axles pushes the coupler down onto the ball; weight behind the axles lifts it. Big Tex's loading instructions describe exactly this geometry when they split gross vehicle weight into the share the axles carry and the remainder the hitch picks up, and that second share is what makes tongue weight the deciding number.

The reason that remainder has outsized influence is that it is the only part of the load the tow vehicle can feel. A coupler is a force connection, and vertical load there is what keeps the trailer's yaw motion damped at speed. Get it wrong on the light side and the trailer can develop an undesirable sway at towing speeds; get it wrong on the heavy side and the rear of the towing vehicle can be overloaded.

Which means a load can pass a GVWR check and still be wrong. Total weight is a single scale reading; tongue load is a relationship between where the mass sits and where the axles are. Same car, same gear, same total, shifted forward or back on the deck, produces different trailer behavior, and only one of those placements matches your model's figure.

Weigh the Car and Gear Before Placement

You cannot distribute what you have not weighed. Before the car goes up the ramps, three numbers need to exist: the empty weight of the trailer, the weight of the car, and the weight of everything else headed for the deck, including ramps, fuel cans, spares, the toolbox and tiedown gear. A public scale produces all three, and the empty trailer weight is the one owners skip.

GVWR is the ceiling and it does not move. The total weight of the trailer and its contents must never exceed the trailer's gross vehicle weight rating, so the usable payload is GVWR minus the empty trailer. That envelope covers the car and the equipment as well as the trailer itself, and the tongue load is a share of the total rather than something added on top of it, which is where optimistic math usually fails: the car gets counted, the support gear gets estimated, and the margin quietly disappears.

Do the arithmetic before you pick a layout. Suppose the car and gear together come close to consuming the whole envelope. Placement still matters, and it matters more, because you now have almost no room to fix a tongue-weight error by adding ballast or by shifting one heavy item, so every correction has to come from weight you already loaded. That is the case where the order of loading has to be right the first time.

Put the Car and Heavy Gear Over the Axles

Stability depends on keeping the center of gravity as low as possible, and the placement rule that follows is to load heavy items on the floor and over the axles. Both halves come out of the same physics. A high center of gravity adds a roll moment the suspension and tires have to fight in every corner and every crosswind; mass sitting between the axles splits across the axle group instead of turning into a lever force at the coupler.

In practice the car goes over the axle group, not hanging off the tail of the deck. Rear deck space is for light, bulky items. A toolbox, a generator, a stack of spare wheels belong on the floor near the axles, inside the tongue budget, rather than perched on a rail where the mass is high and behind the axles at the same time.

This is where deck-space thinking breaks. A car plus equipment rarely fills a deck evenly; there is usually a gap at one end, and the reflex is to close it with whatever fits, which puts gear at the extreme rear. The reason that is the wrong instinct is leverage: every pound behind the axles subtracts from coupler load instead of adding to it, so closing the gap made the trailer lighter on the ball and less stable at speed.

Check Left and Right Balance Before Strapping Down

Lateral balance gets skipped because the deck looks flat from the ramp. Uneven left and right load distribution can cause tire, wheel, axle or structural failure, so this is not about how the load looks in the mirror.

What makes a side-to-side error sneaky is that nothing announces it while you load. A car set on the centerline still leaves the trailer uneven if the equipment is packed down one side, and the rig will tow straight while one tire and one spring carry a disproportionate share for the entire trip. Nothing breaks at the ramp; the consequence lands later, in a tire, a wheel, an axle or the structure.

Run a quick side-to-side sanity check before you tension anything. Look at how the deck sits over the tires on each side, where the car's centerline falls relative to the deck centerline, and where the asymmetric items ended up, the spare, the jack, the cooler that went wherever there was space.

Straps do not fix this. Tension holds a load where it already is; it does not move mass across the deck. A load that is off-center when you start pulling is off-center when you finish, just harder to correct.

Use Your Trailer's Tongue Spec, Not a Generic Percentage

Big Tex publishes tongue-weight percentages as examples and then states that those numbers are for example purposes only and should be tailored to the specific trailer, with a note to check with the manufacturer for the actual figure. That is not hedging. Tongue percentage falls out of where the axles sit relative to the coupler and how the usable deck sits relative to both, and those dimensions vary between models.

Borrowing a percentage from a forum thread or from another trailer's manual calibrates you to a lever you do not own. It cannot be generalized, because identical weight placed on two different decks produces two different coupler loads.

So the target is a number you look up for your trailer, not a range you infer for trailers in general. Once you have it, the check is concrete: the tongue and hitch have to carry the proper amount with the load in place, which means somebody measures that share instead of assuming it from the total.

A Load Order for a Car Plus Equipment

The order that avoids rework runs like this. Confirm GVWR and the three weights first, because that is the only step that can shut the job down early: if the car plus gear will not fit inside the payload envelope, no amount of shuffling fixes it. Next comes the car. Heavy equipment goes on the floor over the axles. Then left and right, then tongue load against your model's figure, then total weight against GVWR again.

Two of those steps are coupled, which is why they cannot be treated as independent checks. Moving the car forward increases coupler load and takes weight off the rear axle group; moving it back does the reverse. Change the car's position after the lateral check and the lateral check has to run again, because the car is the heaviest single item on the deck and its position sets the side-to-side split for everything around it.

Final confirmation is three numbers, not one: total weight at or under GVWR, coupler load at your model's figure, and a deck sitting level side to side with everything strapped. If one is off, you know what to change, total, fore-and-aft position or lateral position, instead of standing behind a load that looks fine and reads wrong.

When This Loading Method Is the Wrong Fit

This method is scoped to one manual and one family of trailers. It holds for a Big Tex single-tire trailer where you have that model's tongue figure and can weigh the load. Loading a different model, a different axle configuration, or a trailer whose tongue spec you cannot find still follows the same physics, but the number you would set belongs to a different lever, and example percentages are not transferable.

If the model's actual figure is missing, that is the thing to chase before the car goes on, through the manufacturer or the spec sheet for the exact model and year, rather than a percentage copied from something that looks similar.

For a fleet operator or an owner with a Big Tex single-tire trailer and the right tongue figure in hand, the payoff is a load that sits inside GVWR, carries its intended share on the coupler, and tracks without sway, settled in the yard, in that order, before the truck moves.