RV OWNER’S FIELD GUIDE · TOWING, CHASSIS & ROAD
Weighing Your Rig — CAT Scale Guide
Your door sticker tells you the max. A CAT scale tells you the truth — what your rig weighs right now, per axle, loaded the way you actually travel. It costs about the price of a tank of gas and takes ten minutes.
The three-weigh method
A single pass over a CAT scale gives you steer, drive, and trailer axle totals — useful, but not enough to separate tow vehicle weight from trailer weight. The three-weigh method does. Weigh 1: the full combination, hitched, with the weight-distribution bars engaged, as you tow. Weigh 2: same spot, still hitched, bars released, which shows the true hitch (tongue or pin) load on the truck and how much front-axle weight the bars restore. Weigh 3: unhitch and weigh the tow vehicle alone. The math: hitch weight = weigh-2 truck total minus weigh-3 truck total, and loaded trailer weight = weigh-1 gross minus weigh-3 total. Fifth wheels and goosenecks have no bars, so weigh 2 is skipped and the method becomes hitched, then truck alone.
Travel loaded exactly as you would for a real trip — full water and propane, gear stowed, passengers aboard if practical. A rig weighed empty tells you nothing about the number that matters on the highway.
Reading the ticket
The ticket shows steer axle, drive axle, and trailer axle weights plus a gross total. Compare each axle figure against its individual GAWR (axle rating, also on the data plate) — an overall total under GVWR can still hide one axle running over its own limit, especially with unevenly loaded cargo bays.
If any number comes back over rating, the fix is redistributing or removing weight, not re-rating the vehicle. See GVWR, GCWR & Payload Explained for what each figure means.
OUR TOOL KIT
Gear for weighing and loading
AstroAI digital tire pressure gauge — Check pressure cold, before you drive.
TST 507 TPMS (4 cap sensors, color display) — Pressure and temperature per tire, so a slow leak shows up before a blowout.
VIAIR 300P portable air compressor — 150 PSI, enough to air up a low tire at the roadside. Same pick as our recommended gear page.
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