Adjustable Wrench
Having a wrench when you’re stuck on the side of the road is invaluable. Make sure it’s somewhat of an all-purpose wrench, adjustable to most sizes and maybe even with a hammer edge to it (often called a “shammer”). If you could only have one tool for your car, make it this one.
Socket Set (+ Socket Wrench)
Socket Sets come in a wide variety of sizes and prices, grab something mid-range that has enough sizes to fit most/all of the common sizes of nuts and bolts. Make sure it includes a socket wrench if you don’t already have one – getting one with an extension bar is a huge added bonus too. Not everything is going to be easy to reach! Make sure you have the right sizes for your car.
Screwdriver Set
Get a set with multiple screwdriver tips and sizes for the most flexibility, just to cover all your bases. Sometimes, things come loose in your car, whether from age, vibration, or anything else. Even the newest cars aren’t safe from this. Finding something loose and tightening it can often solve the problem, and that’s where a screwdriver of the right size can be a lifesaver. Even if you’re not an expert, popping the bonnet and looking for obvious problems like a loose battery connection, a slipped clamp, or anything else.
Torch
This one is simple. If you break down in the dark, whether it be late at night at the way home from work or early in the morning before the sun has risen, you’re going to struggle to fix your car if you can’t see anything. That’s if you can even figure out the issue in the dark.
A simple, compact LED Torch can do the job, but a head-mounted light is extra helpful so you can use both hands on whatever it is you need to fix.
Duct Tape
Duct tape is extremely useful for handling temporary repairs, such as a leaking hose, a broken fan belt, or a cracked or hanging body panel. It's also handy in a million other non-automotive situations. Duct tape fixes everything – at least, temporarily. Be sure to get quality tape, as the more expensive stuff sticks better and in a wider range of temperatures and situations. Be your own MacGyver!
Pliers
A good pair of pliers can be like an extra set of hands – and if you’re doing your own impromptu automotive repairs, a second pair of hands can be invaluable! Keep a few different pairs in your boot if you can to cover all bases, including needle-nose pliers, locking pliers, and adjustable pliers. A pair of snips, or at least a pair of pliers with snips included, can be helpful as well!
Pocket Knife
Parts coming loose isn’t always the issue when you break down. Sometimes, it’s something that’s suddenly attached to something it shouldn’t be! That's where a knife can help. If you’ve got something dragging along the road or jammed somewhere, just cut off the offending part and get back on the road.
A knife can also help if you find your car inoperable and end up stranded somewhere. It has a myriad of uses, from opening food containers to cutting tinder for an emergency fire.
Jumper Cables
Trying to start your car and finding that you’ve got a dead battery is frustrating. Such a simple piece of equipment, and yet its failure can completely disable a car. Even if the battery itself can no longer hold a charge, a set of jumper cables can get you back on the road in a jiffy! Grab a pair of heavy-gauge cables with durable, high-quality spring-loaded clamps on each end – not a pair of smaller, cheaper cables. Definitely avoid the kind that plugs into the cigarette lighter! A proper set of jumper cables is more useful and will work with a wider array of cars and trucks, not to mention last you longer.
Tyre pressure gauge
A tyre pressure gauge is a tool you should be using the most often, ideally at LEAST weekly. Keeping tabs on the pressure in your tyres can prevent blow-outs from under or over inflation, as well as maximizing the life of your tyre tread and your petrol consumption.
Pay special attention to tire pressure around the changes in seasons. Seasonal weather and temperature can have a surprising impact on the air pressure in your tires. If you're headed out on a trip, always check your tyre pressure before you leave. You don't want to get across the state in an unfamiliar area when a slow leak turns into a flat tire.
Tow Strap
A tow strap can be used to move an otherwise disabled car short to medium distances with nothing more than the help of a passing stranger in a 4WD. If you're that stranger in a 4WD, you can use it to offer the same help. The tow strap's durable nature also makes it a good all-purpose strap, if you need to tie something down or hold something together.
Be sure to read your car’s manual to find the proper tie-down and tow points for your car before you try using it. If you should need to use it, a poorly placed strap can quickly cause damage if it's attached to the wrong section of the car.
Fire Extinguisher
A fire extinguisher is a crucial piece of equipment to have stored in your car. Your car catching fire is a very unlikely and rare occurrence, but it’s still something you need to be prepared for. Keep one in your vehicle, and keep it somewhere that you can easily access in an emergency. A bigger one is better, as some smaller “car-sized” fire extinguishers can struggle to put out an actual blaze – but it’s important that it still fits somewhere that can be easily accessible.
Don’t forget to check the expiry date on the extinguisher and regularly check to make sure it’s still good. You don’t want to find yourself in a situation where you need the fire extinguisher, but it ends up as a dud.
Honourable mentions:
Wheel Chocks: Perfect for increased safety when you’re changing your tyre. A portable jack can be dangerous to work with – this adds a layer of security.
Spare Tank: Keep a spare tank of petrol in your boot for especially long trips! Just don’t store it in there too long.
Water: Perfect for cooling down your car in an overheating situation, plus if you’re stuck somewhere, it can keep you hydrated.
Bungee Cord: Even if you have a tow strap, this is the best thing to tie something down or wrap something up with.
Window Punch: This is a small tool used to easily break your car windows in an emergency, such as being trapped inside your car with your door jammed shut. These often come with a blade perfectly suited to cut your seatbelt if you’re stuck in the belt and can’t get it unbuckled.