Contrary to popular belief, modern oil life monitors are not based on a set number of miles but is determined using a complex algorithm.
For a variety of reasons, you might find out your car is reminding you, you have 0% life of oil left, and you must get an oil change immediately.
But, what if you can’t feasibly get an oil change anytime soon and need to keep driving?
Will I damage my engine if I drive past 0% oil life?
Like a lot of things, it depends.
But, here’s why, in my opinion, you’ll likely not damage your engine catastrophically and can squeeze by driving one (or two more times) past 0% oil life.
How oil life monitors work
As mentioned, most modern oil life monitors today are not simple mileage calculators where, after a set number of miles, your oil life is calculated based on that (for example 5,000 miles driving with a 10,000 mile oil change interval = 50% oil life left.)
There also isn’t some laser sensor shooting a beam of electroanalysis light past your oil, constantly monitoring how “healthy” your oil is.
Instead, most oil life monitors use a complex algorithm taking into account driving variables like outside temperature, oil temperature, engine speed, and overall driving characteristics to determine the correct oil percentage to display.
And, since your engine doesn’t exactly know what kind of oil (cheap or premium, what grade, and etc.) these algorithms are set up taking a broad snapshot of consumer grade oils available at the time.
There’s a safety factor built in to the algorithm to take into account different types of oils, too.
Regardless, these oil monitors are quite accurate but, because of variables they can’t control, they’re also not 100 percent accurate, either.
For example, here’s what Honda’s Maintenance Minder does,
“…the Honda Maintenance Minder system automatically adjusts the maintenance intervals based on engine operating characteristics, your driving habits, and the climate.”
“For instance, mild highway driving in a warm climate will maximize the interval between required maintenance. This could be as high as 12,000 miles. On the other hand, short-trip driving in a cold climate may limit the maintenance interval to 3,000 miles or less. In general, most people will indicate maintenance needs about every 6,000 miles. “
If you’re at all curious how exactly the algorithm was developed, Honda published a paper titled “Development of Engine Oil Deterioration Monitoring System.”
Ford’s Intelligent Oil Life monitor system works similarly, taking into account variables and your driving habits to display the correct oil life.
According to Your Mechanic, here’s what driving conditions match up with expected oil life when it comes to Ford’s IOLM.
OK, what if I drive past 0%, and, what can I do if I can’t get an oil change?
The good news is driving 1 mile past 0% oil life will not damage your engine.
I’d even go as far to say driving 300 miles past 0% will not damage your engine.
Automotive manufacturers know there is a percentage of drivers who will flat out ignore the oil life monitor for far too long and, as mentioned, have built in some wiggle room/cushion into their oil life monitor algorithms.
Guaranteed, there are drivers out there driving thousands of miles past 0%, their engines likely undamaged.
Regardless, there are a couple of things you must do if you want to continue driving past 0%.
First, physically confirm you have enough oil, that means popping the hood, and checking your dipstick.Embed from Getty Images
If oil doesn’t register, or you’re low, absolutely add the correct amount using the right type of oil (consult your owner’s manual, so you don’t make a mistake!)
Remember, the bottom hash mark means your vehicle is one quart low. The top hash marks means the engine oil is full. The difference between the two marks is one quart and the lines between said hash marks represents 1/4 of a quart. (source)
Then, drive normally.
Don’t drive aggressively or too far, either, just where you need to go.
Driving habits effect oil life, and racing your engine needlessly will only accelerate oil deterioration.
Finally, get an oil change ASAP however you do it, dealership, quick lube shop, or DIY.
Make sure they/you reset the oil life monitor when done.
Oil life monitors are more accurate than you think.
Regardless, driving past 0% won’t necessarily damage your engine.
But, driving past 0% for too long will increase the likelihood of accelerated wear and tear.
It’s safe to drive a bit more past 0%, but you need to get an oil change, soon.