Thinking About Oil/Filter Change

I don't believe you need to do a mini-major every 3-5K miles, pull the heads, replace every gasket. It's expensive. Probably overkill, if you aren't seeing any obvious issues.

But dude. Seriously. Do you serve your freshly-prepared dinner on leftover scraped plates from breakfast, or do you grab clean plates from the cabinet?

Spend the $14 on the oil filter and do it the correct way.

 

On my '82 308GTSi the oil filter never drips a drop when changing. Not sure what the difference is on 328 vs 308. After replacing the filter I hit the kill switch and crank until the oil light goes out not very long at all. Then start as normal.

 

That sounds messier than it should be. I barely get any mess at all. Are you properly warming the engine up before you drain it, and allowing sufficient time for all the oil to leave before you remove the filter?

No, but I doubt you'd be wearing socks that had been worn for a year and not laundered.

 

The oil filter is cheap enough that shouldn't be mind changing it even if it only has few miles on it.

 

You should change the filter every time you change the oil. Period. If you're making a big mess while removing the old filter then you aren't doing something right.

And no, you would rather have an empty new filter rather than a filled old one. Starting the engine with the right amount of oil with an empty filter will not cause engine oil starvation. The filter fills immediately with a lot of oil to spare.

If you don't want to change your oil after 1000 miles, then don't change the oil. But to change the oil while leaving a dirty filter in place defeats the whole point of changing the oil.

OR, let us know the SN of the car so we can avoid it when it comes time to sell. (That's what Brian always says.)

-F

 

Dumbest question in a long time. Do what the heck you want and stop asking asinine questions.

First off, if you start your car, drive it to warm up the oil and then pull the filter there will be oil in the filter which is why you make a mess. Either wait or take a phillips head screedriver and punch a hole in the filter to let the oil drain. As you don't drive the car just wait til the next morning to replace the filter which will take 2 minutes and there will be no mess.

Anyone who does not replace the filter is dumb, cheap or lazy. Maybe all 3. You give me one reason not to replace the filter. Exactly.

 

In the first example, the filter media was soaked in oil for 1 year.
In the second example, the media was soaked in oil for 2 years.

There's the difference.

The media inside the filter breaks down over time, and loses it's ability to do magical things. In addition, short/small trips have a greater impact on the oil/filter than longer extended trips.

Some of the actuals on what is happening to your oil and filter would require chemical analysis. But the basics here are sound. If the filter only cared about pure miles, then you could technically put 100 miles/year on your car, and change the oil (and filter) every 10-15 years. No one would recommend that, of course.

 

You'd change the filter for basically the same reason you change the oil.

I mean, the reason you change the oil after only 1000 miles is you just don't want one year old oil, even though it still has more life in it mileage wise. Well, the oil in the filter is as old as the oil in the crank case.

Or not. It's your car.

-F

 

You come in here and ask a question. When people give you an answer you don't agree with, you then ask for a technical reason for their answer. I help you understand why you are getting oil dripping all over your engine to help you make the oil filter change less painful.

IMO, you waste alot of peoples time with a very minor point and you still have not provided one reason for not changing it other than you get oil all over your engine, which is why I gave my answer. Help make you reflect on what the real root reason for your resistance to change the filter after you said is not an economic.

So once more why would you not? Just one tecnical answer please.

 

But then again, for a lousy $15 or less, why not replace it,what harm can it do?

 

The true test is whether or not you will tell a prospective owner you don't change the filter each time you change the oil. I know I'm not providing a technical based answer but we all know how anal prospective Ferrari buyers are. Its $15.00 and a little clean up. Not a big deal. Just do it and move on.

 

You would justify a change of oil even after low use to ensure you have no moisture and combustion byproducts sitting in the car if it goes into in seasonal storage. It is absolutely overkill, but there is some benefit to storing with fresh oil. If you do not seasonally store, but just use the car for limited periods during the year, changing after one year is just not necessary. I would say even every two years would still be overkill, but nothing wrong with a bit of overkill on an expensive vintage engine.

There is a standpipe in the oil filter so even if you let it sit/drain overnight (or use an awl and punch a couple of holes, that's what I do, if you pull the filter straight up nothing should leak out), there is still about 1/3 the oil filter volume sitting in the filter. I think not changing the filter is reasonable, that's not much old oil verses the huge new volume that goes into the car. Probably that much in volume residue stays in the engine anyways, you can't drain every drop. So if you feel good to do the oil every year, doing the filter every two is completely fine.

The arguments about change it anyway, its cheap, are of course correct , in that if you were truly "cheap" you wouldn't change the oil either for maybe 3 or 4 years, especially if certain synthetics, where they make it extended drain interval for a reason and changing out expensive oil frequently is not making use of the additive package. You should use cheaper oils (they are cheaper because the additive package is cheaper, not the oil itself) for more frequent changes. I do not like waste. The cost is not the issue, its the principle of limiting waste. If the filter cost $1,000, no one would change it after 1,000 miles of use. Just because it is cheap is not an excuse for waste.

 

1) Changing the oil and filter, on a regular basis, is the only maintenance in my opinion that matters the most. But, just my opinion.
2) I would never consider changing the oil in any vehicle without changing the filter.
3) I have run multiple vehicles to 200K+ miles with regular oil & filter changes, plus other scheduled maintenance, on original motor.
4) How long do you plan to keep this car? (If <10 years who cares?)

 

Oh, regarding the filter since it's vertical why in the world would you try to install one with oil? It can only leak and make a mess. My Rx-7 had a vertical oil filter. On such a vehicle it's impossible to install with oil inserted.

I have decided the idea of inserting oil into a filter before installation is insane. The lack of lubrication in the seconds before the engine is satiated is minuscule.

Again, how long are you going to drive the vehicle?

I have an almost 30 year old Harley I drive regularly and I don't worry about filling the oil filter before installation. And that old bike has 138,000 miles.

 

If you use the correct filter that has the stand pipe inside the filter then you can put oil in side about 2/3 full and install without spilling. This is why hardly any oil spills out when you remove the old one.

 

Hi Lawrence,
I think you question is a good one, and being an engineer myself, I'm not fond of anecdotal or tradition-based (or ego-based) answers.
I took your question to someone I met who spoke to our Automotive Association at the annual conference. His answer is below.
Basically, he says there is no simple answer because of the variety of climates and driving habits among us all. However, each of us can have an answer tailored to our situation by sending our oil in for analysis. This is not expensive, and will give you the answer you seek. I'd be very curious if in fact some of us are doing oil changes needlessly too often, and wasting perfectly good oil.
Cheers,
Robert


A technical definition of when to change oil is when the acid level of the oil exceeds the base number, when the level of solids (soot, etc...) exceeds the dispercency (ability to suspend solids) of the oil the or when the oil is contaminated with high levels of water, fuel or something else that impairs the ability of the oil to function properly.

I doubt many people would argue with that definition, but the question is most likely how to know when those conditions have been met (or are close to being met).

The most reliable way to know the condition of your oil is to perform routine used oil analysis. That is the method that provides data. While some other methods do exist, used oil analysis is the most reliable method. I am currently working on a method to test all three of these in the field (no more sending in a sample and waiting). However, that technology is not ready yet.

In the meantime, arbitrary methods such as calendar based or mileage based change intervals leave much room for improvement. Here is why.

The chemical degradation of oil is called oxidation. The rate of oxidation depends on the environment. For example, a humid environment that sees regular temperature swings is much more likely to increase oxidation than a dry environment that sees relatively stable temperatures. That is why oil can “go bad” in an engine during storage - the environment can induce oxidation and contamination (water condensation in humid conditions).

The problem with mileage based change intervals is that driving conditions have a massive impact on the rate of oxidation. Contrary to conventional wisdom, light driving over short intervals is actually harder on the engine oil than high speed driving over long intervals. In fact, it is better for the Oil to drive 80 mph through the desert than to drive 1 mile each day through the Winter in Minnesota. Short trip driving never allows the oil to warm up enough to evaporate off contaminates like water and fuel. As a result, short trip driving will result in a shorter oil life compared to longer trip, highway driving.

And one more thing, don’t trust the Oil life monitor to give you 100%, fool proof information. You see, Oil life monitors are not actually sampling the oil, so it is not the same as actually sampling the oil to determine the condition of the oil. Instead, the oil life monitor functions by using a computer algorithm to predict oil life based on the operating conditions of the engine. Think about it like a debit and credit system, and based on how you drive the car, the computer adjusts the expected oil life. If you do lots of short trip, cold weather driving, it should adjust the oil life to compensate for that.

In the end, I recommend doing used oil analysis on regular basis (at least once or twice a year) to develop a good baseline for your specific vehicle and driving conditions.

I hope that helps. Please let me know if you have any questions.

Thanks,

Lake Speed, Jr.
Driven Racing Oil

 

Clarification: Actually, your question was about not changing the filter when doing an annual oil change. I did not get a response to that, but instead to the related question of how often must we change our oil.