Axle totals hide dangerous imbalances. Here's why wheel-position weighing is the only way to know what your tires are actually carrying.
Most RV owners who weigh their rig do it at a CAT Scale or a truck stop. They get a ticket showing steer, drive, and trailer axle weights, compare them to their GVWR and GAWR ratings, and head down the road confident their rig is within limits.
That confidence can be misplaced. An axle total is the combined weight on both sides of an axle — left plus right. It tells you what the axle is carrying as a whole. It does not tell you what each tire is carrying individually. And those two numbers can be very different.
An axle with a 6,000 lb GAWR can show a 5,800 lb axle total — 200 lbs under the limit. But if 3,400 lbs is on the right side and 2,400 lbs is on the left, the right-side tires are carrying 400 lbs more than half the GAWR. That single side is overloaded even though the axle total looks fine.
Side-to-side imbalance isn't a flaw — it's physics. RVs are asymmetric by design. The slide-out is on one side. The refrigerator, water heater, and holding tanks are on one side. The entry door is on one side. You load one side of the basement first. Over the course of packing a trip, most RVs end up carrying meaningfully more weight on one side than the other.
The result is that most RVs in the real world have measurable side-to-side imbalance. A 5–10% difference between left and right is common. Differences above 10% are a load distribution problem worth correcting before you roll.
Tires are the most consequential component in this chain. An overloaded tire runs hotter, wears faster, and is significantly more likely to fail. The leading cause of tire-related RV accidents is not a nail in the road — it's a tire that was carrying more than it was designed to handle, quietly degrading until it lets go at highway speed.
Tire manufacturers build their load ratings with a specific inflation pressure in mind. When you overload one side of an axle without knowing it, you're also running that tire at the wrong pressure for the actual load — even if your inflation matches the placard. The placard pressure is based on an assumed even distribution. Real-world weighing reveals when reality doesn't match that assumption.
Weighing each axle end separately and using the heaviest end weight is the only reliable method for setting correct tire inflation pressure on an RV.
— Michelin Tire Corporation, RV Tire Safety guidelinesEven when the total axle weight is within the gross axle weight rating, one side could still be overloaded. Weighing each wheel position is the only way to know.
— Goodyear Tire & Rubber CompanyTrue corner weights — individual left and right readings per axle — require portable axle scales placed under each wheel independently. Intercomp, Longacre, and similar manufacturers make scales specifically for this purpose. You weigh each wheel pad individually and record the four numbers.
CAT Scales and commercial truck scales give you axle totals only. Their fixed arch platform cannot isolate individual wheel positions, and the elevated platform angle makes side-isolation impossible for multi-axle trailers. If a CAT ticket is all you have, enter half the axle total in each corner — you'll still catch axle-level GAWR violations, but you won't see side-to-side imbalance.
A CAT Scale ticket gives you steer, drive, and trailer axle totals. Enter half of each axle total in the left and right fields in RigIQ. Your GVWR and GAWR checks will be accurate. Your side-to-side balance percentage will show 0% — that's expected, since the data isn't available from axle totals alone.
There are two types of scale experiences most RV owners encounter:
If wheel-position weighing isn't available to you right now, a platform scale or CAT Scale is a valid starting point. Knowing your overall weight and whether you're within your GVWR is genuinely useful information — even without per-corner data. Get the basic reading when you can, and add per-wheel weighing when you have the opportunity.
The hierarchy: something is better than nothing → axle totals are better than overall totals → corner weights are best.
The limitation of platform and axle-split scales is that they hide side-to-side imbalance. An RV can be within GVWR and within every axle's GAWR on paper while one side of an axle is significantly overloaded — and neither a platform scale nor a CAT ticket will show it. That's the gap that wheel-position weighing closes.
When you do have access to portable axle scales — through an RVSEF weighing event, an RV rally, or your own set of scales at home — that's the time to get the full picture. In the meantime, every weigh is worthwhile.
Whatever method you use, the weighing results are only as useful as the conditions under which you weighed. A few rules that apply every time:
RigIQ's Weights tab has fields for left and right corners on every axle of both your RV and your tow vehicle. Enter your readings and RigIQ instantly calculates axle totals, compares each side to half-GAWR, and shows your side-to-side balance percentage — all color-coded so problems are impossible to miss.
Pro users can import weigh ticket photos directly. RigIQ reads the axle values and fills in the fields automatically.
Enter your readings from any scale. RigIQ compares every side against GAWR, flags imbalances, and generates a PDF safety report for your records.