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every oil manufacturer has their own policy. only AMSOIL states that you could change your oil at 25000 miles or one year interval using their new EA oil filter. whichever comes first. at first i was doubtful when i started using their product a more than a year ago. but a lot of readings and research made me confident that i did the right thing. try using AMSOIL synthetic oil and amsoil EA filter and you'll see how convenient it is and how it would save you money. in addition to this, you can be confident that your car will be there for longer years. help yourself and give it a try. click on the site below to learn more details of these products.

meanolfart wrote:

 
To All:

I am new to the forum, but I have a follow up question to one posted by terigox.
If synthetic oil does in fact last longer that conventional oils why couldn't you go
7500 miles between changes, but change oil filter at 3000?
THX
MOF  

jspech22a on 11-25-2005  wrote:

Actually by the time you get to 75,000 miles it may be too late to switch to synthetics. I see a lot of critisism for synthetics on here but the fact is there is only one synthetic oil worth spending the money on, amsoil. That's because it is formulated to last so long. As far as oil getting dirty, Amsoil has a new "EA" filter with nanofiber technology, the holes that catch the dirt inside the filter are one 80th the size of one hair, and they can hold many many times the dirt of regular oil filters, such as Fram, etc. check out amsoil.com and if you want to order anything I am a dealer, my email is ianmac1@cox.net if you're interested.


- - - - -
Hmmmm,, "fact" eh?  I suspect Mobil or Quaker state or Synlube 4Life or any other dealers would have a different set of "facts".  
Lets keep this an open discussion rather than just another opportunity to spin and sell a particular product. Yes, they may be good, but beyond that, lots of independent  testing has shown very little difference betweent he various brand - synthetics or conventional.

But thanks for warning us of your bias

Cheers

SH  

BAJAsr wrote:

I was just reading everybody messages and discovered that the differences among synthetic and conventional oils may not be of a big concern. But, a friend was teling me that she was putting sinthetic oil in her 175K 1980 LeBaron Chrysler. I found that very strange and decided to tell her that she would better stay like that. But, woul it be better for her to immediately switch to conventional oil before something bad occurs? I will appreciate if anyone has an opinion. Thanks.

im new, but here goes, ive got a 1992 prelude, its done 170,000ks i run a fully synthetic 5/30 castrol oil, change with filter every 5000ks or so, it consumes about 2l of oil over that period. i have run a good quality mineral oil before, and i could feel a substantual lose of power. i thrashed the *** of the car for 30,000 ks held full throttle redline for extended periods, and the car still runs like new, i never thrash the car when its cold,  it just depends on your type of engine! your not going to put synthetic in a 1980s cast iron block diesel are you??? high reving multivalve engine that gets thrashed, i would. its great!!  

I read some funny stuff in this thread.
Even with the worst oil, 3,000 miles is not necessary, with synthetic it's absurd!!!

The truth is, the mileage between oil changes is influenced by 3 major things:
- Driving habits;
- Engine;
- Driving environment.

In order to "really" find out how long an oil can perform, you HAVE TO do oil analysis. The same thing is valid for filters.
Let's say that you got a new car... Break it in using the existing oil in the engine. Change it with synthetic, and use a good filter. Drive it as you will drive every day. Than, after every 1000 miles send a sample of oil for analysis.
After many miles... and reading the reports, you will notice that your oil is "expired" or almost "expired". CHANGE IT!!! You will not have to do any more analysis, unless you want to...
For every oil change reduce the miles between changes with 500-600.
Change the oil filter and send it for analysis. You will find out if it is able to filtrate the oil or not. If you use a good one, the response is positive. (I have seen a lot of people paying $6.00 for a quart of oil and spending $4.00 on a filter... This will never work!!!)

An advise (after a lot of analysis and a lot of oil tested)

Best synthetic oil: Amsoil and Mobil 1 - both usable for 16000 miles;
Worst synthetic oil: Quaker State - 8000 miles;
Best oil filter: Mobil 1 - running perfect after 16000 miles;
Worst oil filter: too many to list;

Oil additive: perfect for ruining the performance of your oil.

The above results are "valid" only for me. My wife "ruins" the oil a lot faster, usually 2000-3000 miles less than me. That's why I mentioned Driving habits as a factor for oil changes.

I'm driving a Toyota Camry, 1996, and I have as of now 248918 miles on it, I change my oil every 10000 miles using Mobil 1 synthetic oil & filter (I redid the analysis at 200000 miles and the results were good for less than 11000 miles on an oil change). Oil consumption is a little bit less than a quart for 10000 miles. Average speed on highway is about 80MPH.

The decision is yours. Nobody is forcing you to change your oil every 15000 miles. I can not say the same thing about 3000 miles...

Below find a link to an interesting article on synthetics. Has a lot of purported data on synthetic oil properties and tests that were run on both conventional and synthetic oil -- much done by independent (of oil companies) testers. Covers a lot of the points of discussion brought up in this thread plus others and has at least logically sounding explanations for conclusions. Articles bottom line? Synthetics are better in a number of areas as from this quote "Chief among the areas in which the pre-planned and predictable properties inherent in premium synthetic lubricants significantly surpass those of premium petroleum oils are: low temperature fluidity... and thus improved ambient startup protection; low volatility (higher boiling point...greater resistance to evaporation); high-temperature thermal stability; oxidation resistance; lubricity; fuel economy; film strength, and wear protection; extended drain capabilities; water stability; and high *natural* detergent characteristics (resulting in a cleaner engine with less additive content)."

I'll leave it to you to read the article to see how all these advantages result in benefits to the engine.

http://www.mr2.com/TEXT/synth_oil.txt
 

I am wondering how the fully synthetic oil should look like.

I have recently switched from the conventional oil to Mobil 1 EP 5W-30 for my 2005 4 cyl Camry at 9,000 miles. Today, after about 1,500 miles, I have realized that the oil is relatively dark. I would say it's darker that the conventional oil was after 4,000 miles. I change oil/filter at Toyota dealership, so they always put same Toyota filter.  

Do you have any ideas why it's dark? Should I change this oil now?

girvil wrote:

I read some funny stuff in this thread.
Even with the worst oil, 3,000 miles is not necessary, with synthetic it's absurd!!!

The truth is, the mileage between oil changes is influenced by 3 major things:
- Driving habits;
- Engine;
- Driving environment.

In order to "really" find out how long an oil can perform, you HAVE TO do oil analysis. The same thing is valid for filters.
Let's say that you got a new car... Break it in using the existing oil in the engine. Change it with synthetic, and use a good filter. Drive it as you will drive every day. Than, after every 1000 miles send a sample of oil for analysis.
After many miles... and reading the reports, you will notice that your oil is "expired" or almost "expired". CHANGE IT!!! You will not have to do any more analysis, unless you want to...
For every oil change reduce the miles between changes with 500-600.
Change the oil filter and send it for analysis. You will find out if it is able to filtrate the oil or not. If you use a good one, the response is positive. (I have seen a lot of people paying $6.00 for a quart of oil and spending $4.00 on a filter... This will never work!!!)

An advise (after a lot of analysis and a lot of oil tested)

Best synthetic oil: Amsoil and Mobil 1 - both usable for 16000 miles;
Worst synthetic oil: Quaker State - 8000 miles;
Best oil filter: Mobil 1 - running perfect after 16000 miles;
Worst oil filter: too many to list;  

Oil additive: perfect for ruining the performance of your oil.

The above results are "valid" only for me. My wife "ruins" the oil a lot faster, usually 2000-3000 miles less than me. That's why I mentioned Driving habits as a factor for oil changes.

I'm driving a Toyota Camry, 1996, and I have as of now 248918 miles on it, I change my oil every 10000 miles using Mobil 1 synthetic oil & filter (I redid the analysis at 200000 miles and the results were good for less than 11000 miles on an oil change). Oil consumption is a little bit less than a quart for 10000 miles. Average speed on highway is about 80MPH.

The decision is yours. Nobody is forcing you to change your oil every 15000 miles. I can not say the same thing about 3000 miles...  

To wojobattier,

I am new to the forum and have a question myself, but am not new to synthetic oils so will add some of my experiences on synthetics before I ask my question.

I have used Mobil 1 since the year it first came out - over 20 years ago - maybe closer to 30. When it first came out, Mobil stated you could use it for 25,000 miles without a change. That statement was eliminated from advertising in subsequent yrs, but I have always assumed Mobil did it for liability purposes rather than because the product wouldn't hold up. Mobil 1 has always been good for me. Have used it in every one of my cars since IO started and never had an oil related problem. Changed oil between 5 and 7,500 miles initially, but extended that to 10 - 12,000 miles in the last 5 years with no problem. Cars lasted between 150K and 250K miles, and the reason for replacing a car was never wear based on engine wear. (normally have a mix of highway / city driving with between 20 and 30,000 miles/yr., cars ranged from Tercel (economy) to high HP Camaro, driving style brisk at times, but seldom abusive)

Finally owned a car that was as good as the oil (1990 Acura Integra) and gave it to my son at 225,000 miles. Car now has just under 300,000 miles and is running extraordinarily well. No valve clatter, no ring slap, no oil burning to speak of (maybe a qt every 4,000 miles?) It is this car that finally confirmed the value of synthetics to me - it has to be a joint effort between car and oil to get to such a high mileage - and I never babied the car.

I highly recommend synthetic oils. Unsure if it matters what brand is used, but I don't think you can go wrong with Mobil 1. My best guess is that most major brands (reputable brands) are fairly equivalent, but I would not go with either std oils or additives. And not because I know them to be unreliable, but because with synthetic oils now out, I don't see how you can beat a full synthetic. I have seen a number of ads for Prolong that were almost unbelievable, (running car without oil for extended period of time without damage, etc) but there are so many different additives, I will not take a chance on them as long as I can use a 100% synthetic.

Only other thoughts I might add are :

1) always change filter when you are changing synthetic oil
2) use a name brand you can trust
3) make sure you know whether you are using a 100% synthetic OR a synthetic BLEND. There is a big difference in both price and product
4) I do not automatically recommend 100% synthetic. You need to decide this for yourself based on your needs. Moisture / water will normally build up in a cars oil under certain conditions, and while regular oils will pass moisture through the engine under normal use, synthetic oils do not do this as well. I am not an engineer nor am I qualified to go into any detail here. I merely suggest you talk about it with a reputable mechanic who knows your car, driving habits and driving environment to see what he might suggest, and just be aware of the difference. I happen to use the 100% synthetic and have not had a problem.

Good luck with the Honda Civic. Based on all the data I've read, both Honda and Toyota are at the top of the food chain for reliabilty and dependability. I (with substantial regret) have ceased buying American cars for now. I hope GM makes it through the next 3 - 5 years without too much bloodletting, but I think they are in for some very difficult times in the years ahead.

Now for my question (which I may have to copy and re-post since I doubt many people have read all the way thru my response to you )

I recently became interested in diesel cars and picked up old Mercedes. Diesels have approx. twice the cpmpression (22:1) as most gasoline vehicles, use a less refined fuel, and have a different requirement for engine oil and change frequencies.

I have tried to study up on what oil(s) are best to use with diesels and have had a problem finding what I would consider to be independent testing of car oils. I have heard of both "Amsoil" and Synlube" which both advertise extended oil change intervals. Amsoil advertises I think in the range of 25,000 mile intervals and Synlube advertises in the range of 150,000 miles (???!!!!)

Does anyone out there know of a diesel owner who has experience with either of these two oils. I am currently continuing to use regular oil with a 3,000 change interval, but I would like to change both diesels over to a longer change interval IF possible. (I still expect oil filter canisters would require routine change outs even if the oil is not changed every 3,000 miles)

I appreciate any help with suggestions or reference to applicable research articles anyone can offer.

Thanks for the help!


 

Hi People. New guy here. Here's a bit of info that from my experience working as both an automotive and diesel engine mechanic in the civilian and military sectors. In order to take the guess work out of whether any fluid is good or bad, some type analysis must be done in order to know the actual conent and physical condition of any fluid. I don't care whether it's comes from the engines, transmission, gearbox, axle, power steering pump, or any type of equipment that you want to extend the life of. I have about 10 years worth of knowledge using Oil Analysis Programs with the Dept. of Labor, U.S. Army, and in the Transportation Industry. The Automotive manufacturing industry uses oil analysis in their powerpant divisions to get an idea of how long a warranty to put out on the engines and transmission. Having regular analysis will save you time and money. It will tell you if your oil is contamenated with the presence of dirt from your intake, coolant, fuel, and any abnormal wear such piston rings or bearings. As for the question of conventional motor oil vs synthetic, Oil analysis has show that sysnthetic oil work much better at reducing friction between parts and resisting viscosity breakdown under extreme temperatures. As far as which systhetic oil to use? Independent test have shown that Amsoil and Mobile 1 are number one and two respectively in synthetic oils.Amsoil's 100% Systhetic can actually go 25,000 mile between changes.I highly recommend have your oil oil analyzed and getting a complete system fulsh  before adding synthetic oil. Normally when oil is drained, there is usually about 3/4 of a quart still left the engine. if the old oil was contaminated, so will the new oil be when it is added.   But let me also advise everyone an that its not just the type of oil that you use, but also the type of filtration system you use.  The first is the standard $5.00 Full Flow filter that is on most cars. Which is the one main reasons that oil goes bad. They are designed  to trap particles of dirt and metals usually as small as 25 to 15 microns. Anything smaller the filter can't stop from flowing back into the engine to wreck havoc. They are also very poor at traping fuel or water that enters the oil. No need to explain more about that. If that worries you; and it should, spend the extra cash and get a filter that traps particles down to at least the 5 micron level. Make sure that it states that will trap fliuds like water, antifreeze, fuel. Do the same for the intake (air) filter also. Trust me on this one. I've seen to many oil samples where there were high levels of silicon (dirt), which is very abrasive, beak an engine down. It should trap mosture too because condensation in the combustion chamber will rust it out as well as get into your oil. If you are interested extending the life of your engine past it's warranty, look into installing a Single or Duel Stage Bypass Filtration system on your vehicle. They work in conjunction with the Full Flow filter by catching the oil that is circulated to the top of the engine through the drilled passagesfrom the Fluu Flow filter to the PCV valve on the valve cover. That oil is send to the Bypass filter for even further filtering and sent back to the oil pan to be recirculated. The Duel Stage System is the choice if you plan on keeping it at least 8 to 10 years. You only need to get the old sampled and change the filters at 6 and 12 months intervals and add oil to the new filter. I've overhauled diesel engine trucks using Amsoil's synthetic oil and the Bypass Filtration System that had not had an oil change for over 350,000 miles. Should have seen the look on my face when saw how good the rings and bearing were. They looked like they came out of a truck with only 20,000 mile on it. If  you do the numbers you'll save over the long run.
Hope this was helpfull.

question i have a 91 chevy pikcup with close to 300,000 miles and i ahve been using conventional oil the time would be alright to use a synthetic blend would that help or would that not be good
           thanks,
           Darcy  

Ok it's me again. I apologize for being biased, and yes I am an Amsoil dealer, but mainly to get the discount for myself. I do want everyone to know that I do honestly believe it is the best product, although that is my personal opinion. And for people wanting to know if they can switch with high miles, some say its ok, some say it's not. The fact is, and I mean fact this time, it that its ok to switch as long as your engine is mechanically sound, and you don't have any sludge build up. Most of the time with higher miles on conventional oil you will get sludge, sometimes even if you change every 3,000 miles. Sludge can sometimes fill in spots where seals have gone bad, creating a temporary seal to a permanent problem. If you don't know for sure, it's a risk when you switch. Sometimes its hard to tell, that's why some people say do, some say don't, but it seems like you get different stories. If you know for sure you have no oil leaks, have had your engine flushed consistantly while using conventional, I would say it's ok, but if you have very high miles, sometimes you can be pushing your luck. I hope that informations is somewhat helpful.

 

One more thing to the guy on here trying to market Castrol.
   A recent law was made to where motor oil companies can put a certain percent of regular petroleum oil in their product, and still label it 100% synthetic. Castrol is one of the companies that jumped on that opportunity to save money. It is not fully synthetic, neither is Mobil 1, or Valvoline Synpower. Amsoil is the only one out of all these that is still a true, 100% synthetic oil. Just some food for thought. Anyone who doesn't believe me, just google, "Castrol isn't fully synthetic."
If you have question for me, I'm at ianmac1@cox.net.
 

This may also help. http://www.performanceoiltechnology.com/castrolmobilandpao.htm
 

there isnt a big difference between synthetic and regular motor oils.. their both about the same and the "optimum performace" oils are just a money making sceem.. use the oil type that the car requires ex. 10w30 10w40 5w30 etc.  

if you have high mialege vehicles stay with the oil you have been using change it more often and change the filter everytime you change the oil and vise versa no reason to flip flop all the time