Preparing Your Tyres for a Summer Road Trip

Australian summer stacks the odds against your tyres: 40-degree days, hot bitumen, a fully loaded car, and hundreds of kilometres at highway speed, often far from the nearest tyre shop. A tyre that copes fine with the daily commute can fail under that combination. The good news is that a proper pre-trip check takes about ten minutes and catches almost everything. Here’s exactly what to look at.

What should you check on your tyres before a summer road trip?

Work through five things: pressure, tread, damage, age and the spare. The NRMA’s pre-road-trip car checks put it simply — look over each tyre for excessive or uneven wear, cuts and embedded nails that could cause a puncture, reset the pressure to the recommended level, and make sure the spare is road-ready and inflated. The table below is your driveway checklist.

How should you set tyre pressures for a loaded summer trip?

Set pressures when the tyres are cold — before you drive, or after the car has sat for a few hours — because driving heats the tyres and temporarily raises the reading. If you bleed air from a hot tyre to hit the placard number, you’ll be under-inflated once it cools. Many cars list two figures on the placard: a normal figure and a higher one for full loads. With four people, luggage and a roof box, use the loaded figure — our loaded family road-trip guide walks through it. Don’t let air out to “allow for” summer heat; the placard already accounts for normal warming, and correct cold pressure is your best defence against the heat that builds on a long, hot highway run. Keeping tyres properly inflated through the heatwave months is the single most important pre-trip step.

How do you check tread, age and damage?

The legal minimum tread depth in Australia is 1.5mm across all principal grooves — not the 1.6mm you’ll see quoted on overseas sites. Use the moulded tread wear indicators (the small raised bars in the grooves): if the tread is level with them, the tyre is at the limit and due for replacement. For long summer highway driving, and especially if you’ll hit tropical downpours, more tread than the bare legal minimum is safer. If a tyre is close to the limit, sort it before you leave — see when to replace tyres.

Then look closely at each sidewall and tread face for cracks, cuts, and any bulge or blister — a bulge means the internal structure has failed and the tyre must be replaced, not repaired. Pull out embedded stones and check for nails or screws. Finally, read the DOT date code (a four-digit WWYY stamp — week and year of manufacture): rubber ages even with plenty of tread, and Australia’s UV is brutal on old tyres, so treat anything beyond about five to ten years with suspicion and have it inspected.

Don’t forget the spare and the repair kit

The spare is the check everyone skips and the one you’ll curse if it’s flat on the side of the Hume. Check its pressure too — space-savers often need a much higher figure than your normal tyres, and it’s usually printed on the spare itself (see spare tyre pressure). Make sure the jack, wheel brace and any locking-nut key are actually in the car, and that a space-saver isn’t itself perished with age. If your car came with a repair kit instead of a spare, check the sealant canister hasn’t expired. For a quick version of this routine you can run at every fuel stop, see our long-weekend tyre checks.

Frequently asked questions

Should I increase tyre pressure for a loaded summer road trip?

Use the “loaded” or “full” pressure figure on your car’s placard if you’re carrying people and luggage — it’s higher than the normal figure for good reason. Set it cold. Don’t exceed the sidewall maximum, and don’t add extra just to “allow for” heat.

What tread depth do I need for a long highway drive?

The legal minimum in Australia is 1.5mm, but that’s the bare limit. For hundreds of kilometres of summer highway, often in sudden rain, more tread is safer — if a tyre is near the indicators, replace it before the trip rather than risk it.

How old is too old for tyres on a road trip?

There’s no single legal expiry, but many makers suggest inspection from around five years and replacement by about ten, regardless of tread. Australian UV ages rubber fast. Read the four-digit DOT week/year code and have older tyres checked before a big drive.

Do I really need to check the spare?

Yes — a flat or perished spare is worthless when you’re stranded. Check its pressure (space-savers often need more than normal tyres), that it’s not cracked with age, and that the jack, brace and any locking-nut key are in the car.