As a service writer from 2002 to 2020, I’ve asked and answered thousands of questions about cars. After all those years, I’ve found a few items that are truly helpful for drivers to be aware of. If you’re conscious of certain specs, it’s much easier to properly maintain your car or even handle an unexpected repair. Let’s review four vehicle specs you should really know about your own car.

Make sure you know at least these specs for the car you drive:

• Year, make, and model
• Engine oil type
• Fuel octane
• Tire pressure

Year, make, and model might seem obvious. However, if you or someone in your household doesn’t manage cars, the driver needs to know specifically what they’re operating. This will come in handy in any number of situations, from emergency events and sudden out-of-town repairs to local curbside pick-ups.

Further, if whoever changes the car’s oil puts the incorrect weight or viscosity, that’s a big hit to engine longevity. Many internal engine parts continuously move or rotate while the engine is on. These parts require a certain oil chosen by the manufacturer to cater specifically to that engine design. Without the correct oil, parts might not receive proper lubrication. Seals and gaskets can break down. Engine performance will rapidly decline. Check the owner’s manual to observe the vehicle’s engine oil spec.

Similar to engine oil spec, using the correct fuel octane is key to performance and longevity. For example, if you’re installing regular, low-octane fuel in a car that calls for premium, high-octane, you can negatively affect fuel economy. That’s really the best-case scenario. Otherwise, you can cause damage to many components, from spark plugs to even internal engine components.

Finally, it’s important to know your car’s tire pressure spec. The preferred spec isn’t stamped on the car’s tire. There’s a label inside the left front door that has the specific pounds per square inch (PSI) for your car. Knowing the appropriate PSI helps you maintain your tires. I’ve often driven cars with tire pressure monitoring systems, which, in the Midwest, can sound off at the slightest temperature shift. Knowing how far off my tires actually are helps me determine whether I need to stop right away to fill them.

It’s a good idea to write down these four specs and store them in the glove box for anyone operating the car.