All my cars are all old; most are missing user’s manuals. My phone’s huge and expensive so I hate taking it out of my pocket, especially near car work. But I can never remember which car takes which oil, where the Zerk fittings are, and other small-but-significant details. So I make my own reference guides.

A quick reference guide, in our case here, is just a few notes about essential numbers that are hard to remember but important to get right in certain scenarios. I like to decorate my guide because, well, I’m artsy like that. But the “tool” can range from just scribbled notes about which oil filter you need to order to other such trivialities it helps to know sometimes.

Like, how much oil does this thing take? What bulb size do I need for this blinker? Where exactly are the safe jacking points? Where are all the greasable nipples? Or–I just got a flat–what tire size do I need to ask for?

There are plenty of ways to answer those questions. Some of that information is probably written right on your car. Sometimes a person behind a parts counter can look them up for you. And of course, you could always just Google it from your phone.

But in my road trip travels, I have found that when I need them most, those systems I just described can be a letdown.

The person on the till at your local auto parts joint doesn’t necessarily know about cars... or how their own store’s lookup system works, in my experience. And when it comes to Google, it seems like cell service loves to be garbage when I’m standing at a rack of fluids trying to remember if I wanted 5W or 10W oil, showing me nothing but an endless spinning buffering sign when all I want is a number.

And when you can get online... who’s to say the first piece of information you find will be accurate?

That’s why I go straight to the source, before I need to, to confirm all my car’s essential consumables and other similarly occasionally-important pieces of information. I just get things like oil weights, jack points, and so forth, from factory service manuals and parse them into little booklets I pack in my car.

I have found that, for example, owner’s manuals for 1998 Mitsubishi Monteros are annoyingly hard to find and often expensive. Same goes for a factory service manual, and if you could get one, it’d be the size of a phone book. (Remember those?) But service manuals, while hard to find in print, are often online. Which means you can take the pieces you think you might want to look at more than twice and print them out to make a quick reference guide.

My quick reference guide just takes a selection of factory manual pages and stores it somewhere I can grab it anytime I’m in the car. Really, it’s just an attempt to idiot-proof my own car maintenance. But I also like to make the books look cool, and they’re fun to flip through.

My Montero’s is just a Staples folder, with a few selections from the factory service manual put in nice neat-looking pocket protectors. It includes a little illustration on which parts to inspect carefully after off-roading, towing procedures, and the vehicle’s exact dimensions should I want to ship it on the fly. OK, that just plays into my fantasy of international overlanding. But like I said, this is supposed to be fun.

Most people will probably find that they don’t need to rapidly access a few specific car specs often enough to necessitate creating a guide like this, but I do. But most importantly it was entertaining to create.