If you ask a dozen road trippers what tyre pressures they run, chances are you'll get a dozen different answers.
There isn't really a magic formula that works for everyone because there are a lot of variables and everyone has their own experiences.
What is concerning though are the road trippers who only check their tyre pressures occasionally or, worse still, leave them at one pressure for the entire trip, despite the changing road surfaces.
So why do tyre pressures matter?
We're blessed in Australia to have every conceivable road surface available to us . . . mud, sand, corrugated dirt, bull dust, gravel, sealed bitumen and even snow occasionally.
When we go on a road trip chances are we'll encounter most of these road surfaces at one time or another . . . and often in the same day!
And while doing so, our 4WD's are usually fully loaded and often towing a trailer or caravan that can weigh thousands of kilograms.
So the performance we're demanding from our tyres could not be more extreme.
Additionally, tyres made for sealed roads have significantly different designs, construction and tread patterns than those designed for off-road - so we're compromising one way or another and most of us tend to pick something that is a good average for both.
Once you get going on your trip the one thing you can control to maximise your tyres performance and safety and minimise the risk of damage or a blowout, is your tyre pressures.
And the difference is significant!
Setting your tyres at the right pressure for the job can be more effective at gaining and maintaining traction than the tread pattern itself.
Softer tyres on rougher roads are less susceptible to punctures and chipping from sharp rocks and will give you more traction in mud and sand.
But traction is only one issue . . . the bigger issue is safety.
Your life and the lives of your passengers are riding on your tyres!
A tyre blowout can be catastrophic and send you out of control either into oncoming traffic or off the side of the road.
Blowouts are often caused by tyres that are incorrectly inflated for the conditions.
Watch what happens when this Bronco towing a camper trailer gets a blowout.
Wow . . . wow . . . wow . . right?!
So it's essential to invest in your own tyre compressor and tyre pressure gauge so that you're able to manage your tyre pressures along the way without being dependent on a service station.
Dropping your tyre pressures when you get to the rough stuff and re-inflating them again when you get back to the sealed road is 10 minutes well invested and a good chance for everyone to stretch their legs.
What tyre pressures do I run?
Having invested in a few sets of tyres over the past 25 years or so, I've reached what I've found to be the best overall tyre pressures for the driving I do.
These pressures are for my 80 Series Landcruiser which is usually fully loaded on a road trip and often towing our camper trailer.
I'm currently running Cooper ST MAXX 265/75/R16 tyres which have travelled about 60,000km and will be replaced before our next road trip.
These pressures are based on cold tyres, checked in the morning before we get going.
They'll increase by about 4 to 6 psi when they're warmed up after driving for a while.
I've had 3 or 4 flat tyres over the years but they have always been due to sharp objects penetrating the tyre - Tek screw, rivet and a sharp rocks.
But I've actually never had a blowout in over 400,000 km of driving, so there's something to be said for managing your tyre pressures.
DISCLAIMER - This is a guide only - I'm not a tyre expert and I'm not advising you to run the same tyre pressures as I do. You need to do your own homework and I would highly recommend you drop in to a tyre centre that sells the model of tyres you are running and get some expert advice. The pressures you should run will be based on your tyres, vehicle, load, terrain etc which are likely to be different to my setup.
I run 36 psi around town when my rig is mostly unloaded and increase them to 40 psi when I load it up for a trip. Once the tyres are warmed up on a trip they will be at around 45 psi.
Pressure: 36 to 40 psi
Speed Range: 90 to 110 kph
Good Unsealed Road
While I could maintain 36 psi on quality unsealed roads, it's rare to find continuous sections of high quality unsealed roads! They usually include rougher sections, so lowering tyre pressures helps to soften the ride and reduce the wear on the tyres from occasional rocks and corrugations. It also reduces the chances of a puncture through running over sharp rocks.
Driving fast over corrugations to 'smooth them out' with hard tyres will increase your chances of losing control and/or getting a blowout. Let some air out and drive a bit slower and you'll be better off.
Pressure: 30 to 34 psi
Speed Range: 70 to 90 kph
Rough Unsealed Road - corrugation, gravel, bulldust
Where the unsealed road is consistently bad or contains a considerable amount of rough sections, I'll drop down to 26 psi and reduce speed. Tyres will be better able to soak up sharp rocks, ruts and other nasties if they are softer and you are driving slower. Additionally I'll have more reaction time to avoid hitting large tyre shredding rocks and washouts.
Pressure: 26 psi
Speed Range: 50 to 70 kph
Rough track - mud, rocks, creek crossings
This is low range 4WD type track which is probably completely unmaintained and can be any surface you can imagine. Low and slow is the order of the day. Be especially careful when cornering as too much speed & momentum can roll a tyre off the rim. The lower pressure will also help get more traction to climb in and out of creek beds and other obstacles.
Pressure: 22 psi
Speed Range: 10 to 50 kph
Beach driving is risky, especially below the high tide line. The temptation is to drive lower down the beach on the harder sand to get more traction but you also risk being swamped if you get stuck and the tide comes in. The general rule is 16 psi which will give you about double the amount of rubber on the sand and a lot lower pressure per square inch. This helps to float over the sand instead of digging in. If you get stuck or are struggling to get forward motion, lower your tyres more. But remember that with very low pressures comes a much higher chance of the tyre rolling off the rim so drive slow and corner gently.
Pressure: 10 to 16 psi
Speed Range: 20 to 30 kph