Down side of partial oil changes?
- Thread starter WobblyElvis
- Start date
So much effort to do these which gains so little if anything. I'd do a regular oil/filter change or have it done.
If you don't want to do it yourself, why not bring it in? Like Yoda said, " there is no try, just do! " When it comes to oil, it's all or nothing.
How many miles a year do you drive it?
Lately it's been less than 5,000 miles/year.
I'd do a full oil change every 2 years
If you don't shower before and after taking a bath you have only marinated in dirt and soap anyway.
Oil is cheap and cars are expensive. Do yourself a favor and buy yourself one of these:
Or one of these:
Or one of these:
Update:
I finally changed the oil but still no filter change. Sent an oil sample in. The oil used was a mix of mostly 5W30 with a little 0W20 and 5W40 thrown in. Filter has been on over 3 years now and about 13,000 miles. Perhaps November of 24 I'll change it. The oil seems to be doing okay. Depending on how many miles are put on it by next fall, I may change the oil rather than my recent drain a little and top up method.
I finally changed the oil but still no filter change. Sent an oil sample in. The oil used was a mix of mostly 5W30 with a little 0W20 and 5W40 thrown in. Filter has been on over 3 years now and about 13,000 miles. Perhaps November of 24 I'll change it. The oil seems to be doing okay. Depending on how many miles are put on it by next fall, I may change the oil rather than my recent drain a little and top up method.
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Just take the vehicle to a quick lube, why even waste your time and the effort?
Why all these dances? Just take the car in for proper oil change if you couldn't time it to do it yourself before winter weather came.
Back in the old days Mobil 1 changes were change the filter and top off the oil at 7500 mile. Then at 15k it was change oil and filter. If your engine is using a qt every 4k neither of these works. If its blowby then a higher viscosity oil may slow that down. I'd try that and also look for any leaks. If its a leak causing the 4k loss then one of the heavier weight High Mileage oils might be the answer. If neither of these seems to be the answer then maybe an additive to possibly loosen stuck rings? Hard to throw out an answer when the vehicle isn't sitting in front of me. When I worked dealerships I used to ask customers to put the phone closer to the car so I could take a look. You'd be surprised how many took me seriously.
Yeah I really think this is the answer here. Yearly full synthetic change at the quick lube and go on about life.
It's more like a math question.
Lets say total oil capacity is 5.5 qt and you replace 4.5 qt when doing complete oil change
100%-------5k------>18% -------5k------>3% -------5k------>0.5%
so over 3 oil changes almost non of the old oil remains (only 0.5%)
Now, lets assume you replace 1 qt every 1K miles (total 5qt new oil used in 5k)
100%--1k-->81%(=4.5/5.5)
this will take 25K miles (0.81^25=0.005) to reach 0.5% concentration of the original old oil. And you also used a bit more oil.
Full oil changes helps remove old oil 2.5x faster.
Lets say total oil capacity is 5.5 qt and you replace 4.5 qt when doing complete oil change
100%-------5k------>18% -------5k------>3% -------5k------>0.5%
so over 3 oil changes almost non of the old oil remains (only 0.5%)
Now, lets assume you replace 1 qt every 1K miles (total 5qt new oil used in 5k)
100%--1k-->81%(=4.5/5.5)
this will take 25K miles (0.81^25=0.005) to reach 0.5% concentration of the original old oil. And you also used a bit more oil.
Full oil changes helps remove old oil 2.5x faster.
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a solution in search of a problem if I ever saw one.
Z
Z
It's amazing how someone can make a simple task more complicated than it needs to be.
I was afraid that not removing the drain plug for 3 years [ only occasionally siphoning a little out of the dipstick hole ] would lead to a lot of wear metals accumulating in the bottom of the sump. This appears to not be the case or at least the oil analysis doesn't show any sign of this. Those "Mighty Vac" machines probably do a good job. A shop vac with an empty oil jug inside of it can do the same thing.
Wouldn’t that leave the inside of the vac hose pretty oily, a disaster for vacuuming out regular dirt, etc. ?
Z
PS: maybe I’m not seeing the whole picture, but wouldn’t just taking out the drain plug the normal way, or better yet one of the very handy Fumoto valves, be a helluva lot easier.
BTW, I really appreciate the Fumoto on my vehicles. With the tube attached I can direct the oil where I want it to go; no splashing.
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