I'm using full synthetic oil. It's been 4 months since my last oil change and I've only put 3,500k miles since then. I wanted to change the oil after 5,000 miles. Should the amount of months past take precedence over mileage?
Have you driven your car almost everyday? If you haven't, then yes time plays a factor. If this is your second oil change I would go ahead and get it done now. If not I think it safe to go on driving for a few more weeks.
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The answer is yes, time is a factor with mileage - oil does get old. The standard time vs mileage factor is 1 month & 1,000 miles. If you are running full synthetic and were planning to change the oil at 5,000 miles, then you should change it at 5,000 miles or 5 months (whichever comes first).
Synthetic oil is proven to last up to 20,000 miles (20 months) but that is in optimal conditions. Since most of us drive in weather that is either too hot or too cold, the oil's lifespan is shortened due to the extreme conditions. Since a lot of us deal with both very hot AND very cold weather, it is a good idea to change your oil as often as you can, without being excesssive (for example, the 5 months/5,000 miles is definitely a good number for synthetic oil).
Synthetic oil is proven to last up to 20,000 miles (20 months) but that is in optimal conditions. Since most of us drive in weather that is either too hot or too cold, the oil's lifespan is shortened due to the extreme conditions. Since a lot of us deal with both very hot AND very cold weather, it is a good idea to change your oil as often as you can, without being excesssive (for example, the 5 months/5,000 miles is definitely a good number for synthetic oil).
I'm a daily driver and this would be my 5th oil change. I have 13,500 miles on my car. (oil change intervals were at 1k, 3.5K, 7K, 10K). Since i average 3,000 miles/3 months it probably doesn't make much sense for me to use full synthetic if I'm just gonna change the oil every 3.5k miles.
Registered User
I think the mileage is more important than the months. IMHO I do not think the oil or it's additives will decay away in a few weeks or months.
Registered User
I agree, if time was a factor, oil would have a use by date on the container.
Other than the 1 month/1000 mile thing, if you dont drive you car just about every day, the oil starts to go bad.
Registered User
Just curious, but why would the oil go bad if you don't drive it every day?