If you’ve ever stood beside your caravan wondering, “What PSI should I be running for this road?” — you’re not alone. Tyre pressure is one of the most misunderstood parts of caravanning, and it’s also one of the most important for safety, comfort, and tyre life.
The tricky part?
There’s no single “correct” pressure for every situation. Bitumen, gravel, corrugations and sand all behave differently — and your tyre size, load rating, axle weight and speed all play a role.
What You’ll Learn in This Guide
- 🧮 A simple caravan tyre pressure calculator to work out safe PSI for your setup
- 📊 A load index → kilogram table so you can find your tyre’s real carrying capacity
- 🛞 A tyre sidewall reading guide to help you understand all those confusing numbers
- 🚐 Real‑world advice from full‑time travellers on when and why people go lower
- 🌏 Safe pressure ranges for bitumen, gravel, corrugations and sand
- 🔧 A practical, no‑nonsense explanation of how to adjust your PSI for different conditions
Our goal is to make tyre pressures simple, safe, and confidence‑building — whether you’re towing on the highway or crawling through soft sand.
Let’s get into it.
Understanding Caravan Tyre Pressure
Before we jump into calculators, tables and terrain‑specific PSI, it’s important to understand one simple truth:
There is no single “correct” tyre pressure for every caravan, every tyre, or every road.
Your ideal PSI depends on four things:
- Your tyre’s load rating
- Your actual caravan weight on each axle
- Your tyre size and construction
- The terrain you’re travelling on
Most caravanners only ever look at the number printed on the sidewall — but that number is not the recommended running pressure. It’s the maximum pressure at the tyre’s maximum load.
To work out a safe, real‑world PSI for your setup, you need to understand what your tyre is actually designed to carry — and that information is hidden in the tyre’s load index and sidewall markings.
This is where our first tool comes in.
How to Read Your Tyre Sidewall 🛞
Main Size Code
→ LT — Light Truck construction (stronger sidewalls)
→ 245 — Tyre width in millimetres
→ 75 — Aspect ratio (sidewall height as % of width)
→ R — Radial construction
→ 16 — Rim diameter in inches
→ 120/116 — Load Index (single/dual wheel rating)
→ S — Speed rating
Load & Pressure Markings
→ 1450 kg — Maximum load the tyre can carry
→ 80 PSI — Maximum cold inflation pressure
→ COLD — Set pressures before driving
Why These Numbers Matter
→ The Load Index determines how much weight each tyre can safely carry.
→ The Max PSI sets the upper limit for safe inflation.
→ Both numbers are essential for calculating safe caravan tyre pressures.
Where to Find These Markings on Your Tyre 🛞
Every tyre has the same key information printed on the sidewall. Here’s where to look when you’re standing beside your caravan:
- Tyre Size (LT245/75R16) — usually the largest text on the sidewall.
- Load Index (e.g., 120/116) — printed immediately after the size code.
- Speed Rating (e.g., S) — the final letter in the size code.
- Max Load — often printed in a separate block, e.g., “MAX LOAD 1450 kg”.
- Max PSI — printed right next to the max load, e.g., “@ 80 PSI COLD”.
- Construction Info — e.g., “Steel Belted Radial”, “Tubeless”, etc.
These markings are usually grouped together, but depending on the tyre brand, they may be:
- on the outer sidewall only
- on both inner and outer sidewalls
- split across two sections of the tyre
If you can’t find the load index or max PSI on one side, check the inside wall — some manufacturers only print full details on one side.
Quick Tip
Take a photo of your tyre sidewall and keep it in your phone. It makes using the calculator faster — and helps when buying replacements.
Tyre Load Ratings & What They Mean
Every caravan tyre has a load index — a two‑ or three‑digit number that tells you how many kilograms that tyre can safely carry.
For example:
- Load Index 104 = 900 kg
- Load Index 110 = 1060 kg
- Load Index 113 = 1150 kg
This number is critical because your tyre pressure should be based on:
The actual weight your tyre is carrying, not the maximum it could carry.
If your caravan axle weight is lower than the tyre’s maximum load, you don’t need to run the maximum PSI printed on the sidewall.
To make this easy, here’s the table.
Common Caravan Tyre Load Index Ratings 🛞
These are the most common Load Index values used on Australian caravans. Use this table to find the kg rating per tyre for your calculator.
| Load Index | Kilograms (per tyre) |
|---|---|
| 104 | 900 kg |
| 106 | 950 kg |
| 108 | 1000 kg |
| 110 | 1060 kg |
| 112 | 1120 kg |
| 113 | 1150 kg |
| 115 | 1215 kg |
| 116 | 1250 kg |
| 118 | 1320 kg |
| 120 | 1400 kg |
| 121 | 1450 kg |
| 122 | 1500 kg |
| 123 | 1550 kg |
| 125 | 1650 kg |
| 126 | 1700 kg |
| 128 | 1800 kg |
Tip: If your tyre shows two numbers (e.g., 120/116), the first is for single‑wheel setups, the second is for dual‑wheel setups.
Caravan Tyre Pressure Calculator
Now that you know:
- how to read your tyre
- what your load index means
- how many kilograms each tyre is designed to carry
…you’re ready to calculate a safe PSI for your setup.
Enter your details below and the calculator will give you:
- a recommended bitumen PSI
- suggested adjustments for gravel, corrugations and sand
- a reminder of your tyre’s maximum safe limits
This calculator is designed to give you a practical, real‑world starting point, not a laboratory‑perfect number. Always adjust based on conditions, speed and comfort.
Caravan Tyre Pressure Calculator 🧮
Note: This tool provides an estimate only. Always refer to your tyre manufacturer’s load–inflation tables and caravan manufacturer recommendations.
Recommended Tyre Pressures by Terrain
Different surfaces behave differently under your tyres.
Here’s a simple guide to help you adjust safely:
- Bitumen → highest PSI
- Gravel → slightly lower for comfort and grip
- Corrugations → lower again to reduce vibration and shock
- Sand → lowest PSI for flotation and traction
Your calculator has already given you personalised numbers, but here’s the general logic behind each terrain.
Recommended Tyre Pressures for Different Terrains 🚐
These are general guidelines for caravans and camper trailers. Always adjust based on your load, speed, tyre construction, and the conditions on the day.
Bitumen / Highway
→ Use the calculator’s Highway PSI result.
→ This gives the best balance of heat control, stability, and tyre life.
Dirt / Gravel Roads
→ Reduce pressures by around 15% from your highway PSI.
→ This helps absorb corrugations and reduces shock loads on your van.
→ Keep speeds moderate.
Heavy Corrugations
→ Reduce pressures by around 25%.
→ Lower pressures help protect your suspension and cupboards from vibration damage.
→ Slow down — heat builds quickly at low pressures.
Sand (Low-Speed Only)
→ Reduce pressures by 40%+ for flotation.
→ Only suitable for very low speeds.
→ Reinstate normal pressures before returning to bitumen.
Real‑World vs Official Advice
Most tyre pressure charts are written for perfect conditions: smooth bitumen, maximum load, and highway speeds. But caravanners don’t live in perfect conditions — we deal with corrugations, soft sand, potholes, heat, dust, and long days behind the wheel.
That’s why experienced travellers often run lower pressures than the “official” recommendations. Not because they’re ignoring the rules, but because they understand how tyres behave in the real world.
The key is knowing when to go lower, why it helps, and how to do it safely.
Real‑World Traveller Advice (Why Many Caravanners Run Lower Pressures)
Manufacturers set their tyre pressure recommendations assuming perfect conditions — maximum load, maximum speed and smooth bitumen. But caravanners rarely travel in perfect conditions. That’s why experienced travellers often run lower pressures than the “official” numbers suggest. It’s not about breaking rules — it’s about understanding how tyres behave in the real world.
Why Travellers Go Lower
- Lower pressures absorb corrugations better — reducing shock loads on cupboards, suspension and chassis.
- They improve traction — especially on sand, gravel and loose surfaces.
- They reduce punctures — a softer tyre can deform around sharp stones instead of being cut by them.
- They improve comfort — your tyres become the first line of suspension.
- They protect the van — less vibration means less long‑term damage.
But Lower Pressures Come With Rules
- Lower pressures mean lower speeds — soft tyres build heat quickly.
- You must reinflate before returning to bitumen — high‑speed travel on soft tyres is dangerous.
- A TPMS is essential — monitor temperature and pressure as you drive.
Want to monitor your pressures properly? Read our full guide to Caravan TPMS systems — it’s one of the most important safety upgrades you can make.
Our Experience in Ernie
When we’re out exploring in Ernie (our tow vehicle), we’ve gone as low as 25 PSI — but that’s not while towing, and only at very low speeds. Lower pressures give excellent flotation and traction on soft surfaces, but we always reinflate before getting back onto firmer ground.
The takeaway: real‑world caravanners adjust their pressures based on comfort, control and conditions — not just the number printed on the sidewall. Your calculator gives you a safe starting point, and from there you fine‑tune based on terrain and speed.
How to Adjust Your PSI Safely
Adjusting tyre pressures isn’t complicated, but doing it safely makes all the difference. Whether you’re airing down for corrugations or pumping back up for bitumen, follow these simple steps to protect your tyres, rims and suspension.
1. Start with cold tyres
Tyre pressures rise as you drive. Always set your PSI before you start moving, or after a long break.
2. Use a reliable gauge
Cheap gauges can be wildly inaccurate. A good digital gauge (or your TPMS) gives you consistent readings.
3. Air down slowly
Drop a few PSI at a time, checking both tyres on the same axle. They should always match.
4. Don’t forget the spare
Your spare should match your bitumen PSI — not your aired‑down off‑road PSI.
5. Reinflate before returning to bitumen
Soft tyres + high speed = heat build‑up.
Heat build‑up = tyre failure.
It’s that simple.
6. Use a compressor that can handle caravan tyres
Small 4WD compressors can struggle with LT tyres.
If you’re inflating from 25 PSI back to 70 PSI, you’ll want something with decent airflow.
When to Air Down — and When Not To
Knowing when to adjust your pressures is half the battle. Here’s a simple guide to help you make the right call.
Air Down When:
- You’re driving on corrugations
- You’re on gravel or loose surfaces
- You’re crossing sand or soft tracks
- You want to reduce vibration and protect the van
- You need more traction or flotation
Do NOT Air Down When:
- You’re on bitumen
- You’re travelling at highway speeds
- Your tyres are already warm
- You’re close to your tyre’s maximum load
- You don’t have a compressor to reinflate later
⚠️ Speed vs Pressure: The Golden Rule
The lower your tyre pressure, the lower your speed must be.
Soft tyres flex more, which builds heat — and heat is the number one cause of tyre failure.
If you air down, slow down.
Common Tyre Pressure Mistakes to Avoid
Even experienced travellers get caught out by these:
- Running bitumen pressures on corrugations This shakes your van to pieces and increases puncture risk.
- Dropping pressures but not reducing speed The fastest way to overheat a tyre.
- Trusting the number on the sidewall That’s the maximum PSI at maximum load — not your running pressure.
- Not checking pressures often enough Tyres lose air naturally. A TPMS makes this effortless.
- Ignoring axle weights Your tyre pressure depends on the weight each tyre is carrying.
Final Safety Notes
Tyre pressure isn’t a set‑and‑forget number. It changes with weight, temperature, terrain and speed. Use your calculator as a starting point, adjust based on conditions, and always keep an eye on your TPMS.
A few minutes spent checking your tyres can save you hours on the side of the road — and protect your caravan from unnecessary damage.
Caravan Tyre Pressure FAQs
What is the correct tyre pressure for my caravan?
Should caravan tyres be inflated to the PSI written on the sidewall?
How often should I check my caravan tyre pressures?
Do I need different tyre pressures for gravel, corrugations and sand?
Can I drive on bitumen with lowered tyre pressures?
What’s the biggest mistake caravanners make with tyre pressures?
Do I need a TPMS for my caravan?
Should my spare tyre match my running pressures?
Does towing weight affect tyre pressure?
How do I know if my tyres are overheating?
Read our full TPMS guide here: 👉 Caravan TPMS Safety Guide
Wrapping Up
Getting your tyre pressures right is one of the simplest ways to improve safety, comfort and confidence on the road. With the right PSI, your caravan tows better, your gear lasts longer, and your travels become a whole lot smoother.
If you’ve got a question about your setup, drop it in the comments — we’re always happy to help.
