5% oil life left

My dashboard message is that there is 5% of oil life left, and I should have the oil changed. Here’s the question: Is that 5% still protecting at 100% of its expected performance? Or is it about dead. With the carona virus situation, I’m hardly driving anywhere. I think the 5% will take 2 more months to go down to 0. Should I be in a hurry to have the oil changed, or can I wait?

Also…the shops always try to get me to use synthetic oil products. Is that necessary?

Pretty sure your Caddy takes synthetic. I’d get it changed now, with the recommended grade oil. What does your manual say?


The dashboard display is telling you you should change your oil between now and 0% left. Don’t overthink it. It doesn’t mean you have 100% protection 5% of the time nor does it mean only 5% of your engine is getting 100% protection. It simply means you have some time but start planning now to get it changed.

I’m not sure you have to use synthetic but the oil MUST be Dexos approved. Use synthetic if your manual says that is what is required. Don’t try and out-think the people who designed your car.


And here is yet one more example of an individual with an expensive car looking to save a few bucks a year on oil changes.


I will never understand why people want to cheap out on one of the cheapest and easy thing’s to do to help prolong the life of the car.


The owners manual says: Ask for and use full synthetic engine oils that meet the dexos1 specification. Use SAE 5W-30 viscosity grade engine oil.

I’d do exactly that, and change it soon. If you are concerned about Covid-19, wait outside while the oil is changed. If it’s a large waiting room, like a dealership, waiting inside is fine as long as you keep 6 feet from others and wear your mask. An oil change would be a low to medium risk to your health.


What is so hard to understand about changing oil and filter at xxxx miles or xx months which ever comes first . Personally I would change if the oil percentage said 30 % at the least .

Your oil life monitor is not actually testing your oil. Engineers have studied how oil degrades over time and miles on many test engines and they learned how various factors affect the life of the oil. Then they developed an algorithm that tracks your use and determines what the oil life SHOULD be at any given point.

What this algorithm does not take into account is when you use a substandard grade of oil. If your owners manual calls for a synthetic oil and you are using the house brand at discount joe’s , your oil is past worn out.

You need to use the grade of oil that is recommended in your owners manual, or better. Most of us recommend changing the oil at around 20%, it’s like cheap insurance for your engine, but you can go longer.

But I also understand that your concern right now is the corona virus and that is a valid concern especially if you are in one of the at risk groups. Many dealers are using an approved disinfectant on the interiors of all vehicles after they finish the maintenance. The only risk to you is people in the service department that could be Asymptomatic but still contagious.

All you can do here is only deal with a service advisor that is wearing a mask and a fresh pair of disposable gloves and wear a mask your self and keep you distance from all other patrons. If you use a quick lube place, make sure they do the same thing before going in.

If you shop at Walmart etc, you can get your oil changed.


Maybe being so cheap is what enabled them to buy expensive cars?


I would get the oil changed as soon as possible.

As said above, the oil life meter is just an estimate based on mileage driven since the meter was reset, engine hours since reset, or some other algorithm.

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It’s ‘some other algorithm’. GM uses a pretty sophisticated one that accounts for a number of factors. I’d have no problem trusting it. Folks have tested it by sending in samples at low % left, found it wasn’t overestimating oil life.


Interesting. I never figured they put much effort in to train the algorithms. I figured it was just really conservative in its estimates. Thanks for learnin’ me.

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I have the oil changed in our cars at either 6000 miles or every 6 months. It works for me and avoids the uncertainty of the oil life monitors.

And some oils have to be synthetic because a “regular” variety doesn’t exist. We recently bought a Mazda that uses 0W-20. When I went to buy a spare quart, all they had was synthetic.

Even synthetic oil is cheaper than a new engine. Don’t cheap out on oil.


One of the ways I acquired cash to buy an expensive car was to save money when I can. Like not wasting the last 5% of the oil life!
Moreover, in this Covid-19 atmosphere I’m not in a hurry to go sit at a gas station while my car is serviced!

I change mine at 50%, period. I wouldn’t be sleeping at night at 5%. Like Keith said though, it’s just a computer program. It has no idea what the oil is actually like. You could spend $30 and send in an oil sample for analysis but at that point might as well just change it.


Then why even ask for an opinion ?


GM started installing OLMs in the late 1980s. They’ve had a long time to improve it, and IMO have a good product. I used it to determine when to change our 2003 Silhouette engine oil, changing at between 15% to 20%. We donated the van at 187,000 miles and It didn’t use oil.


I’ll second that. My truck does not have a % life output but it does light the service light when the oil needs changing. Any summer I spent towing my 9300# race trailer, the oil light would light at about 4500 miles. Any winter commuting on the highway to work, the light would signal an oil change at about 7500 miles. That, very clearly, showed me how sophisticated GM’s OLM was in 2004.

At 140K miles it runs great and uses a quart every 6K miles or so. These days, I change it at 12 months because I do neither anymore. And I always used synthetic oil. Always.


A new engine costs about $6,000, oil change about $70.00 If you change the oil 3 times a year it would take 25+ years to equal the cost of an engine. Changing the oil is the easiest and cheapest maintenance you can do to keep an engine healthy. ie lower cost in the long run. I am with many others here and would change the oil every 6 months, 6,000 miles or when the OLM hit 20%.


I ask this question. How often, if ever, do you raise the hood and check fluid levels including the motor oil?

If the answer is never then worrying about synthetic oil, oil life monitors, and so on is pointless.

If you check the oil level now and find that it’s low then you can blame that on a couple of things. Going too far on the oil change regimen and running the oil level low. Both contribute to oil consumption by having an effect on the oil control rings on the pistons.