Table of Contents
Introduction
Today, we will run you through tire pressures, applications, PSI, and how to travel on different terrain. So we will go through bitumen driving, dirt corrugation driving, and everybody’s favorite—on the beach to wrap up. So follow me as we go through and give you a bit of a talk-through about the tools, the equipment, and what you need to ensure you’re set up to go anywhere in this great country.
Tire Inflation Equipment
Okay, so starting with equipment — again, if you want to pump up your tires and deflate your tires, you want to ensure that you always have a compressor. So what I’ve done is we’ve grabbed the compressor here out of the workshop, which is a little portable one. Here, you hook up to a 12V battery, so you can hook this to the front of your car battery and then run down to potentially pump up your tires. You’ll see you’ve got your little gauges and all the gear. So that’s one alternative.
But today, I can drive this particular Caravan with an onboard compressor. So again, when you’re going through and looking at decking out your car or Caravan, it may be an option to fit a compressor to your tow vehicle or inside this Caravan. And for ease of shooting this video, we grabbed the Caravan with an onboard compressor.
Tire Deflators and Presets
What have I got in my hand here? Inside, there are some little tire deflators. So again, if you’re going to be going in and out of different types of terrain, and you’re going to be jumping on the beach and then back onto the bitumen, and you’re going to have to be letting your tire pressure down and pumping them back up regularly, you want to be able to do it quickly. Again, letting the tire pressures down can be a pain, but these trusty little tire deflators come with a pack of four, and you can preset these.
So I’ve got these preset at a beach setting — which we’ll run through a little bit later — but I’ve got these set at 18 PSI. If you screw these onto the valve on the actual tire itself, it will let all four down simultaneously. Saves much time. It will stop once it gets down to the pressure it’s been preset at. Okay, so they are a very handy investment. You can pick them up for about 50 bucks again at your local Supercheap, BCF, you know, your auto shops and the like. So that is your little deflators.
But if you want to do beach driving, go on the corrugations, and see some different terrain, ensure that before you set up and deck out your Caravan and tow rig, you have a compressor and tire deflators on board.
Checking and Adjusting PSI for Bitumen Driving
All right, I will check what PSI is in the tires now. We’ve been driving for over an hour, so we’ll get down and check those. This is just a little tire gauge — okay, a little portable gauge that isn’t necessarily the one that is on the inflator there. So we’re going to jump down, we’re going to check exactly what they are, and then we’ll show you this little onboard compressor system here. We’ll get them pumped up to some road conditions.
All right, so we’re shy of 50 PSI. So I’m going to put a little bit of air in there. As I mentioned, we have the luxury of having an onboard compressor in this — it’s part of the airbag suspension system. So, we have a little line out here to use the Airbag Man compressor onboard. We’re plugged in with our Airbag Man inflator; I will go up a couple of PSI to 50 before we hit the bitumen again. I like running at 50 PSI with this tire on the bitumen track.
All right, so I’ll clamp that on there. Again, I can see I’m currently sitting at 47 PSI—see, we’re a couple of PSI short—so we’ll give this a little bit as well. Try to get both these, all four, running at 50 PSI before we hit the bitumen. Beautiful. Cap back on.
Okay, so there we have it. We’ve packed away our gear from our little Airbag Man compressor. It makes traveling so simple when you have all the necessary gear. We’ve got 50 PSI in our all-terrain tires here at the moment. We’re about to hit the bitumen now.
Rule of Thumb for Setting Tire Pressure
Again, returning to that general rule of thumb is good. I’m a simple guy, and I like to keep simple math. Again, I’m not here to give any recommendations because every Caravan differs based on its weight and the particular tire you’ve got. But a little rule of thumb that I’ve always used, that my father taught me when I was a kid growing up is that half of your speed is your tire pressure.
So if you’re doing 100 km/h down the road — generally bitumen travel, blacktop travel — tires will be set at 50 PSI. If you’re hitting the dirt and going between 60 and 80 km/h, you’ll be between 30 and 40 PSI. That way, the tire is going to absorb some of those corrugations. And if you’re on the beach, chances are you’re only going to be 30 to 40 km/h, and therefore, your tire pressure is somewhere between 15–16 and then your 18–20 PSI. So that’s a little rule of thumb that I have always used.
But again, make sure you do the homework based on your manufacturer’s recommendations. We know thousands of you follow this page out there now, and you’ve all got different rigs and setups so that it won’t be a one-size-fits-all. 50 PSI for some road travel — we’re about to hit the bitumen, and then we’ll pull over before we get to a bit of dirt, and we’ll go down and, based on how bad the corrugations are, we’ll either drop these down to kind of 30 or 40 PSI.
Tire Pressure on Gravel and Corrugations
Okay, we’ve just returned through Yankalilla and pulled off to a nice gravel road. We will run the next section here, discussing gravel roads and corrugations. Now, everyone, if you have a few Ks, so in this instance, we only have 5 km of gravel road before we’re back on the bitumen. Unless it is bad, there is no need to come out and let your tire pressures down and then have to pump them back up again.
But if you know that you’ll be in for a good couple hundred kilometers, you know, a couple of hours of corrugated roads where you can only sit on 60 or 70 km an hour, you will shake the living daylights out of your kit, and that is when you want to pull up and lower those tire pressures. So again, when you’re on corrugations, you want the tire to be deflated enough to absorb some of the corrugations as you go through them. You want it to work in conjunction with your independent suspension when you’re working out through corrugations.
They’re more of a feeling. Okay, it’ll feel too rigid if your tire pressures are too high. Okay, it’ll feel like it is giving you a pounding—your false teeth will be falling out and landing on the dash of your car if your tire pressures are too high. So again, this one’s more of a feeling based on the severity of the corrugations.
Again, you may not need to worry if it’s a good gravel road; if it’s only a short distance, you may not. But always have a look at that rule of thumb again. I will run anywhere on corrugations between kind of 25–30 PSI. And again, we’re only doing that kind of 60, maybe 70 km an hour. Sometimes, if they’re really bad heading out towards Lake Gner, you may even be less again.
So again, we’re going to pop these down to 40 PSI just for this video. We’re going to hit this gravel road, and then we’re going to finish off down at the beach. All right now, again, I’ve had these preset at 18. Hence, what I’m going to do is I’m going to screw these on — these going to be heading down as if they’re ready for sand, but I’m just going to stop these, and I’m going to manually test it with our little gauge here, our little portable gauge that we just used a moment ago.
So we know these are set at 50 PSI; we’ve just come off the bitumen. Again, this is a pretty good road, so I’m not going to put this down too low—I’m going to run maybe 35–40 PSI here, and we’ve only got 5 km before we get down to the beach.
All right, so let’s see what it’s down to. All right, we’re down to 40. This road is perfect. I shouldn’t be putting the tire pressures down for a highway this good — it’s nearly going to be as good as bitumen. But again, just for the concept of the video, for what we’re trying to bring to you right now, we want to show you pulling up off the side of the road at the start of the dirt road regardless — corrugations, what it is — have a look at the conditions ahead, see exactly what you’re in for.
Have a look at the road reviews. Again, WikiCamps is great if you’re going to different campsites. They’ll tell you the road conditions when you visit that particular location.
Tire Pressure for Beach Driving
Okay, so here we are at the Silver Sands Beach entrance. Now, we are about 10 minutes south of Old Dinga on the mighty Fleurieu Peninsula and about to drive down onto one of the beaches south of Adelaide. Now, remember that this beach is firm, so letting these tire pressures down is only for this video—tire pressures would not need to come down anywhere near as far on a beach like this, as it is picturesque.
But for this video, I will bring it down as if we were traveling in some soft sand. Now, as a general rule of thumb, whenever we are out and about, I will run 18 PSI in the tires of both the vehicle and the Caravan whenever we’re going onto any form of soft sand—that’s a starting point.
Tire Footprint Theory for Soft Sand
However, if you refer back to one of our videos when we had some experts on here, they were talking about the width of the tire and getting twice the width of the tire in the length of the tire when it’s deflated—so we’re going to test that little theory. I have 265s on here at the moment, so if we look at twice 265, what’s that? We’re 530 mm in overall length of a tire we want to be purchased on the ground.
Okay, now I haven’t got a tape measure. Again, if you wanted to run that rule of thumb, you can grab yourself a tape measure if you’re going to get pedantic with it, but I’ve just done my entire hand span there from pinky finger to thumb around that 265 number that we have here as the width of the tire. Now we want twice that, okay, so we’ll have a look at our purchase here now and where we sit.
So that’s where we sit there, all right. So we want — and again, this is a rough, rough, rough rule of thumb — but if we have a look at the two lines that I’ve put here, our actual surface area of the tire that is currently on the ground running at 50 PSI — as you can see, that’s all that’s sitting actually on the ground.