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Honda 2012 oil life indicator

How is the oil life percentage value calculated? Answer received from the dealership was very lame. Once I receive a reply, I will ask more questions.

A logorithm is used that takes into account the number of times the engine is started, the length of each trip, the temperature of the engine coolant each time it is driven, the amount of stop & go driving, the amount of idling, the amount high-speed driving, and–of course–odometer mileage and elapsed time.

That being said, I would suggest that you err on the side of caution, and would recommend that you have the oil changed when the oil life indicator tells you that your motor oil has about 20% of its theoretical life remaining. Oil is relatively cheap, and engines are expensive.

And…don’t forget to check the oil dipstick on a regular basis.

+1 for VDCdriver.


An algorithm is used to calculate the engine oil life. Not a logorithm.


Now you know why I wasn’t a math major!

The algorithm is based on using the specified oil. If your car calls for a semi-synthetic and you use conventional, you could get into trouble. If you use a full synthetic or extended life synthetic, the the oil life monitor will have you changing the oil before it is actually needed. Once you vary off the specified oil, it becomes a guess on your part. BTW, it does not have to be Honda brand oil, it just has to meet (or exceed) the specifications for Honda.

Anybody know the %-Synthetic in the Honda 5W20 blend?

It just says blend on the bottle with no percentage for about $8. I think the full is just as cheap. I always figured it was about 50-50 but maybe Docnic will know.

They aren’t about to tell you how the software is programed. Its not in the factory manual either. It would be proprietary information for each manufacturer. All they’ll say is that its based on miles, number of start ups, and so on. I just change at 5000 miles or 50% and don’t worry about it. Saving oil is the least of my concerns with owning a car.

I personally suspect the higher milage between oil changes these dumb oil life indicator show is more about browny points with the environmentalist then the longevity of the car. As Bing suggested replace oil every 5K. or every 6 months which ever comes first.

If a car manufactures wanted to put an oil indicator on a vehicle that is useful  it would be a low oil level indicator to warn you the oil is low before engine damage.

Those Dumb oil life monitories could tell you that you have 50% oil life, and you could have no oil in the car and a blown engine because the oil life monitor does not monitor the oil level, so do check the oil level regularly.

+3 to @VDCdriver Add load based on the MAP sensor to the equation, too. These software based algorithms are pretty conservative. Just to be on the safe side, use a little better oil than Honda recommends. I.E. use semi-synthetic if Honda recommends regular oil or synthetic for semi. I use my Honda’s oil light as a change interval with synthetic and just ignore anything else. The oil stays visually clean on the dipstick past halfway to the next change and the engine has 104K. Most other manufacturers use similar algorithms. Since most manufacturers use these for oil life, each has their “special” technique based on millions of test miles.

Great answers. We put 15% on the oil change reminder stickers at the Honda Express Service department that I managed for a few years. This is the % that the maintenance will flash when 1st started to let you know that a service is due soon. The sticker just reinforced what the car is saying. (plus it had our name and # on it) Use the weight oil that Honda recommends, 5w-20, it is on the oil cap. Oil changes now are at much longer mileage intervals than the past. What becomes an issue is tire rotation, which used to be recommended every other oil change. Now with oil changes so far apart, this no longer applies. Hondas, and i believe most cars, need the tires rotated no less often than 7-8,000 miles to get good wear patterns and the longest life out of the tires. Good tires for your Honda are expensive, you want them to last. So most likely you will want to rotate them with every oil change.