The Australian summer is notorious for its extreme heat, with temperatures regularly exceeding 40°C in many parts of the country. These conditions place extraordinary stress on vehicles—from the scorching exterior surfaces to the sweltering cabin and the mechanical systems working overtime to keep everything running. Without proper preparation, summer can cause significant damage to your car and create dangerous driving conditions.
This guide covers everything you need to know to protect your vehicle and stay safe during the hottest months of the year.
Cooling System Maintenance
Your car's cooling system works harder during summer than at any other time. A failure during a heatwave can leave you stranded in dangerous conditions or cause catastrophic engine damage.
Coolant Check and Flush
Before summer begins, have your coolant level and condition checked. Coolant degrades over time, losing its ability to protect against corrosion and transfer heat efficiently. If your coolant hasn't been changed in two years or 40,000 kilometres, consider a flush and replacement. Use the type specified for your vehicle—mixing different coolant formulations can cause serious problems.
- Temperature gauge rising higher than normal
- Sweet smell from the engine bay (coolant leak)
- Puddles of green, orange, or pink fluid under the car
- White smoke from the exhaust
- Heater not working properly (can indicate low coolant)
Radiator and Hoses Inspection
Inspect radiator hoses for cracks, bulges, or soft spots. These rubber components deteriorate faster in extreme heat and can fail suddenly. Also check the radiator for debris blocking airflow—leaves, insects, and dirt accumulate on the front of the radiator and reduce cooling efficiency. A garden hose can gently rinse away buildup from the engine side.
Protecting Your Interior
A car parked in direct sunlight can reach internal temperatures exceeding 70°C. This heat damages dashboards, fades upholstery, cracks leather, and can make your car unbearable to enter.
Windscreen Sunshades
A quality windscreen sunshade is one of the simplest and most effective ways to reduce interior heat. By reflecting sunlight before it enters the cabin, sunshades can keep interior temperatures 15-20°C cooler. Look for reflective shades made from durable materials that won't deteriorate in heat. Custom-fit shades work better than universal ones as they provide complete coverage without gaps.
Window Tinting
Professional window tinting blocks UV rays and reduces heat transmission. In Australia, each state has regulations about how dark tinting can be on different windows—typically, the front windscreen must allow at least 70% light transmission, and front side windows around 35%. Quality ceramic tints can reject significant heat without being excessively dark.
- Use a windscreen sunshade whenever parked in the sun
- Apply UV-protective conditioner to leather and vinyl surfaces
- Consider seat covers to protect original upholstery
- Remove electronics and valuables—heat damages batteries
- Crack windows slightly when safe to allow hot air to escape
Air Conditioning Service
A functioning air conditioning system isn't just about comfort—it's a safety feature. Driving in extreme heat without cooling can impair your concentration and reaction times, similar to driving while fatigued.
Signs Your AC Needs Attention
If your air conditioning isn't blowing as cold as it used to, it might need re-gassing. Refrigerant slowly leaks from the system over time, reducing cooling capacity. Other signs include unusual noises when the AC is running, musty odours (indicating mould in the system), or the AC taking much longer than usual to cool the cabin.
Pre-Summer AC Check
Have your air conditioning professionally inspected before the peak of summer. Technicians can check refrigerant levels, inspect for leaks, test compressor function, and ensure the system is operating efficiently. A small investment in maintenance can prevent being caught without AC during a heatwave.
Tyre Safety in Heat
Hot roads and high temperatures create unique challenges for tyres. Understanding these issues can prevent blowouts and maintain safe handling.
Pressure Monitoring
Air expands when heated, causing tyre pressure to increase. Check your pressures when tyres are cold—before driving or after the car has sat for several hours. Don't be tempted to let air out of hot tyres; they'll be under-inflated once they cool down. The correct cold pressure is listed on the placard inside your driver's door.
Scorching bitumen can reach temperatures over 60°C, accelerating tyre wear and increasing the risk of blowouts, especially on worn or under-inflated tyres. Reduce highway speeds during extreme heat, and avoid driving on shoulders where debris and softer road surfaces can damage tyres.
Tread and Condition
Summer road trips mean more kilometres on your tyres. Check tread depth—the legal minimum is 1.5mm, but replacing tyres at 3mm provides better wet weather grip when those summer storms roll through. Look for cracking in the sidewalls, which can indicate UV damage or age-related deterioration.
Battery Care
Contrary to popular belief, heat is harder on car batteries than cold. High temperatures accelerate chemical reactions inside the battery, leading to faster degradation and shorter lifespan.
Battery Testing
If your battery is more than three years old, have it tested before summer. Many auto parts stores and mechanics offer free battery testing. A weak battery that barely survived winter may fail completely when stressed by heat and air conditioning demands.
Terminal Maintenance
Clean any corrosion from battery terminals using a mixture of baking soda and water. Corrosion increases resistance, making the battery work harder and generating more heat. Apply a thin layer of petroleum jelly or terminal protector spray after cleaning to prevent future buildup.
Fluid Levels and Quality
Heat affects all fluids in your vehicle. Summer is an excellent time for a comprehensive fluid check.
Engine Oil
Oil thins at higher temperatures. Ensure you're using the correct viscosity for summer driving—your owner's manual specifies appropriate oil weights for different climate conditions. If your oil change is due soon, do it before summer rather than after.
Transmission Fluid
Automatic transmissions generate significant heat, especially in stop-start traffic common during holiday periods. Check transmission fluid level and condition. Burnt or dark fluid indicates it's time for a service. Many transmission failures occur during summer due to overheating.
Emergency Preparedness
Summer breakdowns can be dangerous due to extreme heat. Being prepared can turn a crisis into an inconvenience.
- Extra water (both for you and the radiator)
- Sunscreen and a hat in case you're stranded
- Emergency blanket (provides shade when hung)
- Portable phone charger
- Roadside assistance membership details
Driving Habits in Heat
Your behaviour behind the wheel should adapt to summer conditions. Allow extra following distance—hot tyres on hot roads can increase stopping distances. Plan trips during cooler parts of the day when possible, and take regular breaks to combat heat-induced fatigue.
When first entering a hot car, open all doors and let the built-up heat escape for a minute before getting in. Start driving with windows down to push hot air out before switching to air conditioning. This cools the cabin faster and reduces strain on the AC system.
Professional Pre-Summer Check
Consider booking a comprehensive pre-summer vehicle inspection. A qualified mechanic can identify potential issues before they become roadside emergencies. This is especially important if you're planning long-distance summer road trips, where a breakdown could leave you stranded far from help in dangerous heat.
The Australian summer doesn't have to be hard on your car. With proper preparation and maintenance, your vehicle can handle the heat while keeping you safe and comfortable. Start your preparation now, before the mercury rises, and enjoy worry-free summer driving.