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View Full Version : Thoughts on oil changes? Frequency, brand, etc.



Disco Dan
06-30-2007, 07:46 PM
First of all, I'd like someone to find some informed negative reviews of AMSOIL because I'm considering going that route from here on out, but want to be sure first. Considering they have a product which guarantees 25000 mile performance, you can understand the temptation. Moving on...

My dad wants me to change his oil. It's "been about 3000 miles" and he figures that the Mobil 1 is about at its life's end and needs to be swapped out for a new gallon of the stuff. He's got an '03 Mazda Protegé5 with just under 100k on the clock.

I politely informed him "Well, that 3000 mile oil change school of thought isn't really applicable with your engine and the oil in it. Heck, check the Owner's Manual and I'm sure it recommends 5-6k miles."

So, to back up my claims, I started doing some research.

In my research, I came across a name I hadn't heard before, but which I'm sure many of you have: Amsoil.

It kept coming up in online discussions of how often to change your oil, but I couldn't find any real-world applications that tested the stuff. Also, the majority of the people who based Amsoil didn't seem to have any real data to back it up, they would mostly say things like "NO oil will last 15000 miles, just play it safe and get it changed every 3000", which isn't exactly helpful when you're looking for objective information.

Finally, I did find this incredible site, to which I'll post the link, because it has some incredible real-world-application test results using both Mobil 1 and Amsoil:

http://neptune.spacebears.com/cars/stories/oil-life.html

They ran a 2002 Camaro for one year without changing the oil, twice:

http://neptune.spacebears.com/cars/stories/mobil1.html
http://neptune.spacebears.com/cars/stories/amsoil.html


The amount of information and the level of detail that they've recorded is great. Check out the first link for an explanation of the levels they keep referring to.

For those too lazy to read, the Mobil 1 held up for 18000 miles (one year) with one filter change, and the amsoil held up for 14000 miles (time-limited to one year as well) with no filter changes. However, the Amsoil tended to be more viscous over a longer period of time. In other words, it started as 5W30, but when they tested it after 14000 miles and 13 months, the viscosity was at 15W40. That was not so great for the LS1 engine in the Camaro, but I'm wondering how it would affect one of our 4-bangers. For those with the #M-G(T)E series engines (Supras), it seems this would be a great thing, especially the 5M, which is notorious for developing a knock in later life and requiring thicker oil.

Anyway, my questions are these:


I think we can safely assume that 3000 miles is excessive oil changing, even for non-synthetics, but especially for synthetics. The test in the above links tests a 5.7 liter V8 engine. Very few Celicas have that kind of engine in it, so what would be a good number for our engines?

The noted viscosity increase: do our engines like thick or thin oil? I would be prone to lean towards thin, simply because newer Japanese engines tend to be more and more tightly tuned, and I can't imagine a high-revving engine working very well with an engine oil that's two grades above the recommended viscosity. But this is just what I'm thinking based on logic; I have no data to back that up. Any thoughts?

And finally, brand of oil? I'm curious about this Amsoil product, but the Mobil1 I've been using seems to hold up fine and did so in the tests. Even on the Amsoil site, where they post side-by-side product comparisons in various categories, the Mobil1 comes in just below the amsoil in most of the tests.

T-spoon
06-30-2007, 10:26 PM
I disagree completely. Yes, even Toyota only recommends 5k oil changes now. But do you know why? To fit with the tire-rotation service plans they have now, not because it's better for the motor. I change it every 3k in all of mine, and even if it was synthetic it would be every 3k. Oil breaking down isn't and never was the entirety of the issue. Engines are going to get crud in the oil and you want it out. 5sfes and 1mzfes are awesome motors. They're tough and can run forever, but we have tons of them popping up sludged all to hell. I would bet you about anything those motors did not have oil changed at 3k religiously. I also know for a fact that you CAN get away with going 5, 10, even 20k miles without changing regular dyno oil and you may not notice the damage it can do but that doesn't mean it's something you should count on. I bet Amsoil is just fine for many thousands of miles, and so are most synthetics and some dino oil, but I think it's just asking for trouble to push the oil change intervals out further and further as long as the basics of engine mechanics remain what they are.

I believe that pushing service intervals to extremes is just asking for trouble. Cars are enough trouble to upkeep without that gamble. Folk can do as they please, but personally mine gets changed at 3k or 3months, and I recommend that to anyone I talk to.

Disco Dan
06-30-2007, 10:44 PM
Hmm. I should clarify:

I'm not trying to push the Amsoil thing, 'cause I've never used it and have no reason to believe I need to change from the Mobil 1 I do use. Plus it's more expensive.

The main question in my mind is the oil change frequency. And what you've stated is mostly speculative, like a lot of the information that's found on the internet on the subject. I'd really like to get some concrete evidence that changing the oil less fequently does more damage to the engine. Plus, I read about people running their cars to the 300,000 mark, changing their oil once every 5-10k miles. Granted, they could be lying, though it seems like a silly thing to lie about.

T-spoon
06-30-2007, 11:07 PM
Hmm. I should clarify:

I'm not trying to push the Amsoil thing, 'cause I've never used it and have no reason to believe I need to change from the Mobil 1 I do use. Plus it's more expensive.

The main question in my mind is the oil change frequency. And what you've stated is mostly speculative, like a lot of the information that's found on the internet on the subject. I'd really like to get some concrete evidence that changing the oil less fequently does more damage to the engine. Plus, I read about people running their cars to the 300,000 mark, changing their oil once every 5-10k miles. Granted, they could be lying, though it seems like a silly thing to lie about.

It's not speculation exactly. One car may last 300,000 miles, another might spin a bearing at 50,000 and it may or may not have anything to do with oil change frequency. If you want to be SURE that it's not an issue, use a lower interval like 3,000. I don't think it's as complicated as you're making it out :) An expensive oil's "hook" is that you don't have to do it as often, so you can afford to use their product because it will mean less service you have to pay for. The factory recommended interval, as I said, does not necessarily mean it's because it's as good for the car. I know that Toyota's longer interval is an issue of money and service "deals", not any major breakthrough that makes it better to have a longer interval.

Changing the oil less frequently has more POTENTIAL to damage the engine, bottom line. It doesn't guarantee damage to the engine, it just adds more risk. Tons of factors can either contribute to or nullify those dangers.

CHRiS'_CeLiCa
06-30-2007, 11:47 PM
ya oil/filter changes you usually want to keep up with as much as you can, all you need for repetitive car care is gas when its empty(duh) and oil/filter changes every 3-5k i would say, if you do that, then your car will last forever(as long as you dont blow something)....in saying this, i am not saying that cars cant go more than such and such miles w.o an oil change and then they will blow up, cause thats not the case, its just not smart to change your oil and stuff after a long period of time, it will really put a wear and tear on your engine....waiting til the "last minute" to do an oil change everytime you change it, is really gonna just f^<k up the engine in the long run.......thats just my .02 and what i think on oil changes.....personally i do it every 3k (the jiffy lube way! haha) just to be on the safe side and keep the oil clean in there....and def do it yourself cuz you never know what type or quality oil jiffy puts in there, most times its not what you put in the change before and it really messes it up....

alltracman78
07-01-2007, 01:41 AM
If you really want to find out about your oil, send a sample to be tested.

http://www.herguth.com/?gclid=CLShr6COhY0CFQeSHgodzjYehg
http://www.oillab.com/
http://www.blackstone-labs.com/

There are a bunch more.

The military doesn't change their oil at any set intervals, they send it out to be analyzed.
When it's time to change it based on the condition of the oil, and how contaminated it is they change it.
From personal experience the tanks run a VERY high quality synthetic.
The engines are gas turbines, so they run much hotter than ours.
The oil isn't changed for years sometimes.

BUT, if you are really interested in this it all comes down to the specific engine and oil you run.
An engine with worn rings [or a turbo engine] that has alot of blowby will need more frequent oil changes because regardless how well the oil resists breakdown it will become contaminated with soot and other combustion particles.

IMO it's worth it to just change it every 3k to be on the safe side.
It won't hurt anything but your wallet, and it's cheap insurance.

Luis C
07-01-2007, 01:44 AM
Im using Mobil 1, USUALLY the oil goes out every 6.5 K miles and filter is changed every 3.2 K miles but the interval is largely based on how I have driven the car. I know that the oil can hold on for more than 6.5K miles but I wouldnt risk it. Engines are expensive, oil not much so

Ajilon
07-01-2007, 04:59 AM
Having blown an engine from what I perceive as poor maintenance, I've learned my lesson the hard way to change it every 3K miles, regardless. It's not hard. It's not expensive and it's
much better for the car. The cleaner you keep your engine, the better it will perform for you.

Fuelish
07-01-2007, 03:10 PM
I'm in the 3000 miles/3 months camp, and use regular old school dino oil - I'm not particularly brand loyal, but do only use oil from major well-known companies (not the generic crap like sold at gas station mini marts). Combined with Toyota oil filter, so far so good...

vms4evr
07-01-2007, 11:52 PM
Amsoil, Mobil 1, RedLine, Royal Purple (synthetics) are all excellent oils. Which one you use is a matter of personal choice. Amsoil is harder to find because it works as a dealer network so you order it online. I find that not worth the trouble since there is no real proof that it outperforms the others by any big margin.

I love this 3K mile oil change debate because it is the "safe" thing to do, or my dad always did that, or it's cheap insurance, ad naseum... That is such garbage, a waste of good oil, and more oil sent to recycling for no good reason. Surprising as it may seem the quality of oil has improved significantly over the years in many ways. Pick an oil that you want to run. Run it for however many miles that you think is the "magic number" to make you happy. Then send a sample off to Blackstone labs. They have nothing to gain and will report on the oils remaining value and if any metals in your engine are showing excessive wear. If you've got an engine that is starting to get flaky they'll find it. It's not perfect, but a hell of a lot better than following "myths".

I track my Z06 along with a good size group. All the oils listed above are used by different folks based on their past experience, beliefs, whatever. I have yet to see one of them come back with a bad lab report unless the engine was already going. GM put an "oil life algorithm" in the C5s that works very well. I follow it. I'm running Royal Purple synthetics end to end (oil, trans, diff, ps). Last lab report was on 4600 miles. I changed it too soon. That is after street/highway driving, 2 hard track weekends, and 1 autocross weekend. I can assure you my oil gets damned hot running on track for 30 minute sessions at a time. Typically running 235-265 oil temps.

As far as sludge. Cars with very inconsistent use, lots of down time, lots of short trips, lots of cold weather, improper weight choices get sludge. A car with decent quality oil, in the right weight for your engine, that gets driven fairly regularly and allowed to come up to full oil temps will burn off deposits and should not sludge up.

Want to read up more and visit a forum that is dedicated to that.

http://www.bobistheoilguy.com/

You'll see lots of oil analysis reports on all kinds of makes of cars run under all conditions.

As soon as I do the first oil change on this new to me Celica. I'll send it in for a lab report to see what condition the engine is in. At least that way I'll know where I'm starting. Get the facts on your engines status.

NDMstang65
07-02-2007, 12:46 AM
Firm believer in synthetics....Amsoil mainly, but we do run Mobil products as well.

Whenever we build a new engine we run rotella oil in it for break in (still has all the old good enzymes in it and seals the rings really well in the block) then switch to synthetics. We switched our wrecker over all the way through, the transmission runs much much cooler, shifter no longer gets warm, and actually picked up a mile per gallon of gas by switching everything over. Whatever that may be worth, i know that there is less friction, because the heat simply isn't there anymore!

T-spoon
07-02-2007, 07:01 PM
Amsoil, Mobil 1, RedLine, Royal Purple (synthetics) are all excellent oils. Which one you use is a matter of personal choice. Amsoil is harder to find because it works as a dealer network so you order it online. I find that not worth the trouble since there is no real proof that it outperforms the others by any big margin.

I love this 3K mile oil change debate because it is the "safe" thing to do, or my dad always did that, or it's cheap insurance, ad naseum... That is such garbage, a waste of good oil, and more oil sent to recycling for no good reason. Surprising as it may seem the quality of oil has improved significantly over the years in many ways. Pick an oil that you want to run. Run it for however many miles that you think is the "magic number" to make you happy. Then send a sample off to Blackstone labs. They have nothing to gain and will report on the oils remaining value and if any metals in your engine are showing excessive wear. If you've got an engine that is starting to get flaky they'll find it. It's not perfect, but a hell of a lot better than following "myths".

I track my Z06 along with a good size group. All the oils listed above are used by different folks based on their past experience, beliefs, whatever. I have yet to see one of them come back with a bad lab report unless the engine was already going. GM put an "oil life algorithm" in the C5s that works very well. I follow it. I'm running Royal Purple synthetics end to end (oil, trans, diff, ps). Last lab report was on 4600 miles. I changed it too soon. That is after street/highway driving, 2 hard track weekends, and 1 autocross weekend. I can assure you my oil gets damned hot running on track for 30 minute sessions at a time. Typically running 235-265 oil temps.

As far as sludge. Cars with very inconsistent use, lots of down time, lots of short trips, lots of cold weather, improper weight choices get sludge. A car with decent quality oil, in the right weight for your engine, that gets driven fairly regularly and allowed to come up to full oil temps will burn off deposits and should not sludge up.

Want to read up more and visit a forum that is dedicated to that.

http://www.bobistheoilguy.com/

You'll see lots of oil analysis reports on all kinds of makes of cars run under all conditions.

As soon as I do the first oil change on this new to me Celica. I'll send it in for a lab report to see what condition the engine is in. At least that way I'll know where I'm starting. Get the facts on your engines status.


Ok, fair enough. Let me say this though, I've never seen/heard of an engine blowing up because they changed the oil too often. I have seen plenty ruined from not changing often enough (yes, probably combined with other factors, but that's not at all the point).

Rix86
07-02-2007, 07:57 PM
3k miles
royal purple 30 weight.