How to read weight figures and examples
- Ratings are maximum limits, not measurements of your loaded setup. Confirm the exact variant and approved ratings.
- Measure loaded coupling weight. A percentage or the difference between ATM and GTM ratings does not establish today's coupling weight.
- An added load changes both axle reactions according to its position. A change is not a total axle load; use measured starting axle weights and add each load once.
- Combination mass is unhitched loaded vehicle plus total loaded trailer, or the sum of all coupled axle readings. Count coupling mass once.
- Examples and AI suggestions are planning aids, not verified measurements or compliance clearance. Unknown figures require measurement; active weight-distribution hitches and gooseneck arrangements need their own assessment.
ClearPath is an independent educational and advisory platform. We do not recommend or endorse any tyre brand, product or service provider. This article provides general information only; references to specifications are for checking your own vehicle and trailer requirements.
Start with the exact manufacturer specification
Use the vehicle tyre placard and owner’s manual as the authoritative baseline for the exact vehicle variant, approved tyre fitment and operating condition. The caravan or trailer has its own placard/VIN plate and manual. ClearPath does not currently hold verified model-specific pressure specifications, and its weight calculations do not calculate or approve a tyre pressure.
Normal load versus loaded or towing
Some manufacturers publish separate normal-load and fully loaded or towing settings. Use the applicable condition and any stated speed restrictions. Read front and rear figures separately: they may differ. A loaded setting is not automatically a towing setting unless the manufacturer says it applies.
If only one setting is listed, or a towing instruction is unclear, obtain confirmation from the manufacturer or a qualified tyre specialist. Do not invent a PSI increase, copy another vehicle, or use a generic hot-pressure-rise rule to replace the specification.
Trailer and caravan tyres
Check the trailer’s own pressure instructions for the fitted tyre size and construction, including low/high-load settings where available. Tow-vehicle pressures do not apply automatically to the caravan. If its plate is unreadable, tyres have changed, or no suitable laden specification is available, ask the trailer manufacturer and tyre specialist to confirm the appropriate cold settings.
Use measured travel-ready axle loads and, where possible, individual wheel-position loads. Tanks, luggage and equipment can create unequal loads across axles and from side to side; dividing a total weight equally between tyres can hide an overloaded tyre. Have the manufacturer or specialist interpret the correct load/inflation table for the exact tyres and single/dual fitment.
Measure cold, then monitor
Check pressures before driving, after the tyres have cooled to ambient temperature, with a reliable gauge. Follow the manual’s cold-check procedure. Driving warms tyres and raises pressure: do not release air from hot tyres simply to reach the cold figure. Recheck cold when appropriate.
Check every road tyre and spare before a trip and regularly during use, and after a significant load or temperature change. Follow the manufacturer’s TPMS reset and warning instructions. Investigate a warning, repeated pressure loss or damage; a monitoring system does not replace physical checks.
Tyre load ratings and axle loads
The load index describes tyre load capacity under specified conditions; it is not a recommended inflation pressure. The maximum pressure marked on a tyre sidewall is not automatically the correct operating pressure. Check the tyre, wheel and valve limits and the manufacturer’s requirements together.
Weigh the vehicle and trailer as actually used, with passengers, fuel, water, accessories, luggage and the trailer attached. Towball leverage can add more than the ball download to the rear axle while unloading the front. Check front/rear axles, each trailer axle and tyre capacity as well as overall mass. Model axle loads and GVM/GCM, then verify the result by weighing.
Suspension, tyres and GVM modifications
A suspension change can alter ride height without changing permitted masses. A certified GVM upgrade changes only the ratings explicitly covered by its approval. Tyre size or construction changes may also require different approved pressure guidance. Confirm the pressure schedule and tyre load capacity for the exact modified setup with the manufacturer, approved modifier or tyre specialist; retain the supporting documentation. Read the suspension modification guide.
Do not exceed tyre, wheel, valve, axle, vehicle, trailer ATM/GTM, GVM/GCM, towball, towing or manufacturer limits. Increasing pressure does not raise any of these ratings or remedy overloading. Resolve overloads before travel.
Bring these details to your advisory review
Keep missing specifications marked as unknown until confirmed. An advisory weight result alone does not establish that tyre pressures or tyre capacity are suitable. Review your vehicle load or check your vehicle and caravan combination.
Checking the information for your setup
Reviewed 27 September 2026. Use your vehicle and trailer tyre placards, owner’s manuals and applicable approved modification documents to establish the correct pressure settings and limits. This article does not provide a pressure schedule or recommend a product, brand or service.