Change your first flat in the driveway, not on the shoulder

Quick answer: Get well off the road, set the parking brake and loosen every lug nut half a turn before the car goes up. Jack at the point shown in your owner's manual, swap the wheel, tighten in a star pattern and drive no faster than the speed printed on the spare.

The first time most people change a tire, it's 9 p.m. and raining. The car is tilted on a gravel shoulder and trucks are going by at 70. That's the worst classroom there is. So don't learn there. Learn on a dry Saturday morning in your own driveway, with coffee in hand and nothing riding on it.

Go in knowing the part nobody mentions. This job isn't about strength. The lug nuts on your wheels were probably zipped on at a shop with an air gun, somewhere around 80 to 100 foot-pounds on most passenger cars. You won't beat that with your forearms. Neither will most of the men who'd stop to offer. You beat it with leverage and body weight, and anyone who weighs more than a bag of groceries has enough of that.

Open the trunk before you need it

Lift the floor panel today. Plenty of people find out on the roadside that the car isn't carrying what they assumed it was.

• The spare. It's either a full-size wheel or a compact "donut." Many newer cars have neither, just a bottle of sealant and a little compressor. If that's your car, you want to know now.
• The jack and wrench. They're usually in a foam tray or behind a side panel. On a lot of trucks and SUVs, the spare hangs under the rear and gets lowered by a crank through a hole near the bumper. Practice that one. It's fiddly the first time and miserable in the dark.
• The wheel lock key. If one nut on each wheel looks different from the others, that's a locking lug nut. Without its key, nobody is getting that wheel off by the side of the road. Find the key and put it in the glove box.
• Spare pressure. Compact spares often call for 60 psi, and the number is printed on the sidewall. They leak slowly for years while nobody looks at them. A flat spare is just a heavy object you've been hauling around.

What I'd buy, and what I'd skip

The factory wrench is a short L-shaped bar that's barely long enough to do its job. Add a few things:

• A four-way cross lug wrench. Longer arms, room for two hands and far more leverage than the stock bar.
• Work gloves. Lug nuts are filthy, and the spare well is worse.
• A headlamp. A phone flashlight means working one-handed.
• A wheel chock, or a brick that lives in the trunk.
• A 12-volt inflator and a pencil gauge. They plug into the car and handle a slow leak or a soft spare.

What I'd skip is relying on a can of sealant as your whole plan. It can get you to a shop with a small nail hole in the tread. A gash in the sidewall laughs at it.

The step-by-step

1. Get off the road. Far. Flat, firm ground matters more than stopping right away. A parking lot beats a shoulder every time. Rolling slowly on a flat for a short distance may scuff the rim. A rim is cheaper than you are.

2. Lock it down. Hazards on, parking brake on, car in Park, or in first gear if it's a manual. Get everybody out and standing well away from traffic.

3. Chock the wheel diagonally opposite the flat. Flat on the front left means the chock goes behind the rear right.

4. Loosen the lug nuts while the tire's still on the ground. This is the step people skip, and it's the one that matters most. If the car is up in the air, the wheel just spins when you push on the wrench. Turn counterclockwise, half a turn each, no more. If a nut won't budge, set the wrench arm level and stand on it. Keep a hand on the car for balance and bounce gently. Your weight does what your arms can't.

5. Find the jack point. Your manual shows it. It's usually a reinforced notch along the seam under the car, just behind the front wheel or just ahead of the rear. Put the jack anywhere else and it can slip or punch through the floor pan.

6. Raise the car until the flat clears the ground by an inch or two. Remember that the inflated spare stands taller than the flat you're taking off, so leave room for it.

7. Keep every part of you out from under the car. The jack in your trunk is built to lift. It isn't built to hold a car over your arm.

8. Take off the nuts and the wheel. Drop the nuts into the hubcap or a pocket, because one rolling into a storm drain will ruin your evening. Grip the tire at 3 and 9 o'clock and pull it straight toward you. If rust has it stuck to the hub, shove the tread hard from side to side a few times. It lets go sooner than you'd think. Squat, and use your legs.

9. Hang the spare. Line up the holes with the studs and push it flush. Thread every nut on by hand first, with the tapered side facing the wheel.

10. Snug them in a star pattern. Go across the circle, not around it, so the wheel seats evenly.

11. Lower the car, then tighten for real. Same star pattern. Lean your weight into the wrench, firm but not jumping on it. Then stow the flat, the jack, the tools and the chock. People drive off without the chock all the time.

The donut is a crutch

A compact spare will get you to a tire shop. That's all it's for. Most are marked for 50 mph, and many have a mileage limit printed right on the sidewall or in the manual. The car will brake and corner differently on one, so drive like it.

Recheck the lug nuts after the first 50 miles or so, because they can settle. When you get to the shop, ask them to torque the wheel to spec. A puncture in the tread can usually be patched from the inside. A cut in the sidewall means a new tire, and no honest shop will tell you otherwise.

If it was your dad's car or a friend's, don't hand it back with the donut on. Return it with the real tire fixed, the spare aired up and the jack back in its tray where you found it. That's how you get asked to borrow it again.

When you shouldn't do it yourself

Sometimes the right move is to stay put. The flat might be on the traffic side of a narrow highway shoulder, or you're on a blind curve at night, or the ground is soft mud the jack will sink into. In any of those, stay in the car with your seatbelt on and your hazards going, and call roadside assistance. If you feel unsafe, call 911. That isn't giving up. It's judgment, and judgment outranks pride.

If a stranger stops, you're allowed to say "Thanks, I've got it." You're also allowed to say yes. Either way, keep your phone in your hand and stay near your own car. Kind and careful aren't opposites.

The Saturday drill

Do the whole thing once in the driveway, start to finish, and time it. Twenty to thirty minutes the first time is normal. The second time takes half that. Then put the spare back, check its pressure and set a reminder to check it again in six months.

If you've got a husband, a dad or a brother around, ask him to stand there with his coffee and say nothing unless you ask. Plenty of good men find that harder than changing the tire themselves. How he handles it says something too, and it's worth watching what he does when it costs him something, even when the cost is just keeping his hands in his pockets.

The lug nut doesn't care who's holding the wrench. It only cares which way you turn it.