What My Summer Car Teaches About Bolts You Forgot to Tighten

The first time my Satsuma lost a wheel in My Summer Car, I was doing about 70 on the dirt road toward Peräjärvi. The car lurched, scraped, and rolled into a ditch, and I sat there working out what I had done wrong. The answer turned out to be one wheel nut, left finger tight after I fitted a new rim. The game had let me drive off without a warning. It had simply remembered.

I laughed, reloaded, and then went quiet, because two years earlier I had done almost exactly the same thing on my real car. After swapping to winter tyres on the driveway, I forgot to go back and torque one wheel. I noticed a faint clicking on the way to work, pulled over, and found three nuts snug and one loose enough to turn by hand. Nothing happened that day. But I still think about how close it was, and I think My Summer Car is one of the few games that captures why that kind of mistake happens.

A game that tracks every fastener

For anyone who has not played it, My Summer Car is a Finnish survival and car building game from Amistech Games, released into early access in 2016. You start with a shell and a garage full of loose parts, and you assemble a 1970s style Satsuma more or less from scratch. Engine block, crankshaft, pistons, head, carburettor, gearbox, suspension, brakes, wheels. Each part attaches with bolts that you tighten one at a time with a ratchet or spanner of the right size.

Here is the clever and maddening part: the game keeps track of every one of those bolts. If you leave an oil pan bolt loose, the engine may leak oil until it seizes. If a wheel's nuts are not fully tight, the wheel can come off at speed. Forget to adjust the fan belt and the engine overheats. The game rarely tells you which bolt you missed. It just lets the consequence arrive later, often far from the garage.

Players spend hours hunting for the single loose fastener behind a failure. Forum threads are full of people posting photos of their engine bay, asking strangers to spot the bolt they forgot.

Why the mistake happens, in the game and on a driveway

When I talk to readers who have had a part come loose after a job they did themselves, the cause is almost never that they did not know how to tighten a bolt. It is interruption. They got called inside. The light went. They tightened three nuts, went to get the torque wrench, and came back to a wheel they believed was finished.

My Summer Car reproduces that perfectly, because the game is full of interruptions: your character gets hungry, needs to sleep, has to answer the phone, goes to buy beer. You leave a job half done, come back the next in-game day, and your memory of where you stopped is wrong.

The game also exposes a second trap. Fastening something "snug" and fastening it to the right torque are different. In the game, a bolt is either fully tight or it is not. In a real car, a bolt that feels tight to you can still be well under the figure the manufacturer specifies. Wheel nuts on a typical family hatchback are often specified somewhere around 100 to 120 Nm, and very few people hit that by feel. Oil drain plugs are the opposite case, where enthusiastic tightening strips the threads in the sump. If you have never checked what your own car calls for, our guide to doing an oil change yourself covers the drain plug side.

"Just be careful" does not work

The usual advice for avoiding this is to slow down and pay attention. I have never found that useful, because I was paying attention when I made my mistake. Attention fails under interruption. What works is a system that does not depend on your memory.

Mechanics have used one for decades. After a fastener is torqued, they draw a line across the bolt head and the surface beside it with a paint pen. It is called a torque stripe or witness mark. A glance tells you two things: that this fastener has been torqued, and whether it has moved since. Aircraft maintainers use the same idea. It costs about £4 for a pen.

Here is the routine I now use for any job involving wheels, brakes or drain plugs, built partly from what the game taught me and partly from what the old hands at my local shop drilled into me.

1. Before starting, look up the torque figures for every fastener you will touch, and write them on a piece of masking tape stuck to the wing.
2. Put every removed fastener in a magnetic tray, grouped by where it came from. Count them as they come out.
3. Tighten wheel nuts in a star pattern, first by hand, then lower the car so the wheel cannot spin, then torque them.
4. Mark each torqued fastener with a paint pen, straight away, before you touch the next one.
5. Before you drive, walk round the car and look for any fastener without a mark. Count the empty spaces in the tray.
6. After about 50 miles, recheck wheel nuts with the torque wrench. Alloy wheels in particular can settle.

The paint mark replaces memory. If I get interrupted halfway through, I come back and the job tells me where I stopped. Since adopting it, I have not driven off with anything loose that I know of, and the torque wrench I bought for this, covered in which garage tools are worth buying first, has paid for itself several times.

What the game exaggerates

In fairness, My Summer Car is harsher than reality in some ways. Real cars are more forgiving than a game designed to punish. A single loose sump bolt usually announces itself with drips on the drive long before the engine seizes. A loose wheel nut usually clicks or causes vibration before anything comes off, as mine did. Real brake calipers often have bolts with thread locking compound that resist working loose. The game compresses the time between mistake and disaster for drama.

That said, I would rather have players expect a harsh outcome than a forgiving one. The people I worry about are the ones who did a brake job, felt fine for a week, and decided they got everything right. If you are doing that work, our notes on when to replace brake pads explain what to check afterwards.

You can find more of our writing about car games, and what they get right and wrong, in the games section.

Something for this weekend

Buy a paint pen, any bright colour, from a hardware shop or motor factor. Next time you check your tyre pressures, put a small line across each wheel nut and the wheel beside it. You have not torqued them, so this is just a baseline, but from then on any nut that has rotated will show it instantly, and you will have started the habit before the next job that needs it.