I'm thinking of switching to synthetic oil. (5W30) Is it true I can go up to 25,000 miles to 50,000 miles, as long as the oil filter is changed every
10,000 miles? If, so, then, at 10,000 miles do I just remove the filter and quickly put a new one in, and then top off the oil? Is this the way it's done?
Extended drain intervals are possible with synthetic oil but not without work. Oil filter changes are still at the same intervals (actually, I wouldn't go much past 3,000 miles, especially as the oil ages), but if you plan on going past the recommended intervals with the oil then you will need to send samples to a lab that will analyze it and tell you how much life is left in the oil and how much crud it has in it. Only if you get on a regular schedule of sampling and analysis would I go to an extended change interval.
On both my vehicles, I use full synthetic oil and do a complete oil and filter change every 5000 miles with no issues. That is more miles than the
3000 people typically use as a marker, but less than the manufactuer recommends for either vehicle (7500 for one and 10,000 for the other).
You should also consider that if you have an older motor, no matter how good the oil is you will accumulate wear materials and products of combustion in the oil at a pretty good rate just due to the pre-existing wear in the motor, and sampling and analysis will verify that your change interval will more than likely be shorter than what you want.
As for changing the filter, depending on the motor all you have to do is remove the old one an catch the spillage then install a new filter. There is really no need to rush as removing the filter won't also drain the pan. Depending on the size of the filter and how much spillage you may need to top off the level with as much as a quart with every change. 10,000 miles is typically too great of a change interval for a regular oil filter - it still collects junk from the oil at the same rate no matter if you are using regular or synthetic oil, and you will be doing more harm than good if you let it go too long and it clogs up causing the bypass valve to remain open during normal usage (thereby not filtering your oil).
No it is not true. Not even close. Utter nonsense. Maybe, just maybe, you can go 9,000 miles if you change the filter every 3000 miles and depending on the climate and your driving habits.
Recommended Oil Change Intervals for Mobil Motor Oils You state that your oils are for 5,000, 7,500, 15,000 miles, but what are the months before a change is due?
We recommend a maximum of six months between oil changes for Mobil Clean
5000, Mobil Clean High Mileage and Mobil Clean 7500. On Mobil 1 Extended Performance, we recommend a maximum of one year between oil changes.
Also Mobil 1 Extended Performance Delivers advanced performance and guaranteed protection of critical engine parts for 15,000 miles. This fully-synthetic formulation is designed for today's longer service intervals.
Have to consider climate and driving conditions. probably also take into effect the engine size, amount of oil the engine holds, etc etc etc. I play it safe. The beater gets 3K oil changes with the hceapest oil out there (havoline so far) and a new filter. Has worked excellent for years for me. No wear.
The nice car gets premium synthetic and goes 7500 miles between changes (even though the manufacturer says 15K)
Read it again, paying VERY close attention to the last sentence in the article. Also read the single sentence above the last paragraph where it discusses engine wear, and where/when most of it occurs.
Based on the results we've got here, we'd recommend 8,000 miles between oil changes on an engine that uses no oil at all, perhaps 10,000 miles on an engine that uses some oil, and 15,000 miles or beyond with a filter change every 5,000 miles. This, of course, isn't any kind of guarantee, and you must evaluate for yourself what your engine requires. One thing we're pretty sure about though: 3,000-mile intervals is a huge waste of resources.
And of course, "In case it isn't obvious yet, this means that the most wear occurs in the first 3,000 miles"
If this is so, then people who change (synthetic, at least) oil at 3K miles are actually INCREASING wear on their engines.
I personally have used Mobil One in all my vehicles since the late '70s, changing filter at 5K miles, with oil and filter changes every 10K miles. I've run engines over 200K miles doing this, and have never had any engine related problems on any of the vehicles.
IIRC, that guess was related to chemical oil analysis of the oil, not actual engine wear. There was some indication that iron concentration in the oil increases most rapidly right after an oil change and there are those who equate this with engine wear.
AFAIK, even if the observation is correct, the link between increased iron in the oil and increased wear has not been proven.
I would like to see if the same phenomenon is noticed if the air (introduced when the oil is changed) were purged out of the crankcase before the engine is started. The increased iron could possibly be related to simple surface reactions rather than wear.
I am not a big fan of engine oil analyses, and I have been a professional chemist all my professional life.
That article isn't one I trust. Not very scientific. Very amateurish in fact. I saw them drawing conclusions they had no business drawing. Not to say there is no redeemable info in there . I am saying there is enough to stop me from relying on it to much of any degree.
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