VERY interesting test of synthetic oils! The 3000 mile oil change myth debunked!

[Guest bastaad525]

hey all, stumbled across this in a VERY old trashed thread, and found it to be immensely interesting reading. It's a very thorough independent test, sort of to compare two leading sythetic oil brands, Mobil 1 and Amsoil, but also, and more importantly, to show the extreme longevity of synthetic oils in general. Almost worthy of sticky status, I'd say, but I'm not da boss 'round here

 

well here's the link: http://neptune.spacebears.com/cars/stories/oil-life.html

 

I'll summarize it for those who don't want to read three very long pages... basically these independent guys did some very thorough testing on Amsoil and Mobil 1, and found that they were capable of FAR exceeding the 'recommended' 3000 mile oil change interval, going as far as 12,000+ miles before the level of particulates and insolubles in the oil got high enough, or the viscosity changed enough, to warrant a change. That was WITHOUT a filter change, as well... changing just the filter could have extended the usable life of the oil even longer. Additionally they found evidence that changing oil too frequently (3000 miles is too frequently) could actually ACCELERATE engine wear, vs. running the oil for 'extended' intervals. Very interesting reading anyways and makes me glad I've been using Mobil 1 all this time...

[2126]

Interesting read for sure. Isn't it funny how most all oil manufactures still tout the "change your oil and filter every 3000 miles". Its about the $$$....as usual! Mobil #1, as you know, has the new longer mileage oils....5,000, 7,500, & 15,000 miles. I'm guessing that the 5,000 mile stuff is the exact same stuff we've been buying all along....you think? I've been using Mobil #1 oil/filter in both my cars for probably the past 20 years and change it at about 5K miles. I always thought it was a no brainer.....all the good things about synthetic they promoted, over convensional oils, convinced me that changing your oil/filter every 3000 miles was just a waste of money. Now some 20+ years later, they decide to promote to the public what they've known for decades! Interesting, yes?

[Scottie-GNZ]

Great post and I agree worthy of a sticky or being easily referenced.

 

If you were selling oil at $4-5/qt to gullible and lazy Americans you would be pushing 3000 miles also. My 9yr Saab 9000 turbo is pushing 210K on the odometer and gets a filter every 3K and fresh Mobil1 every 15K. Cannot remember the last time I did an intentional "oil change" on the Buick engine but it gets a fresh filter often.

[Drax240z]

Amsoil recommends oil changes every 36,000miles, and filter changes every 12,000miles right on the bottle...

[Forrest]

Yes, I don't believe I've ever seen a synthetic oil manufacturer recommend 3000 mile oil changes. Extended oil life is part of their marketing plan so - not sure what myth you are talking about.

[Pop N Wood]

I have never seen anyone but Jiffy Lube and other disreputable oil change places recommend a 3000 mile oil change interval. Very few cars need the oil changed that often, synthetic or fossil. IMO 5000 miles with dino oil is overkill for most cars. Synthetics I don't even know about.

[Phantom]

I run Mobil 1 and just change both the oil & filter at 5,000 miles. I'm more concerned about acid build-up from blow-by, etc. damaging the engine than particulate build-up or viscosity changes. The new GM's and some other cars tell you when to change the oil based on the type of driving the computer registers and even hydrocarbon based oils often end up getting changed out well over 7,500 miles. then again, GM is in the business of selling vehicles, not oil. Hmmmm.

[Drax240z]

Good point, if you are running excessively rich, or have blow by problems, changing your oil and filter more regularly is probably a good idea.

[SleeperZ]

I run my diesel on regular old diesel oil and change it at 5000 miles. I send it in for analysis, and it reads good for soot concentraion, the additives are working, the viscosity is good. My opinion is you can run oil as long as it's good -- you can check this through regular oil analysis. Every vehicle is different; this 3000 mile thing is BS, and a waste.

[JMortensen]

Anyone seen the aftermarket centrifugal oil filtration setups they use on semis? They spin the oil at 3000g and this forces the heavier soot to the outside of the filter housing where it sticks. Supposedly filter to one micron, and there is no replacement, just open it up and scrape out the sediment that comes out of the oil. The additives in the oil need to be replenished every once in a while with the addition of a couple fresh quarts, but the oil could be used for over 100,000 miles according to the info I was reading a couple years ago. I guess the problem is that they require too large a capacity and too much oil pressure to be effective in passenger cars.

[clarkspeed]

The 3 month/3000 mile change is a hold-over from a previous Millennium. 30 years ago oils didn't have anywhere near the additives they do today. That's why its common for OEM new cars to recommend 7500 changes. They still list the "severe duty" clause, but even that's not a problem if you keep the filters fresh.

 

Synthetics are a whole other ball game. I did a research on synthetics in college and was amazed that the properties are at least 10x better for most specs. The most amazing is it's resistance to moisture. One drop can screw up conventional oil load carrying capabilities and f-up a gear set over time. Synthetics can absorb 100x more than conventional with no deterioration. I'll never use anything else in my boats.

 

It's rare to find an oil related failure on a street driven car. That would take some serious abuse. Synthetics can provide some extra margin if you think you need it. Otherwise it's money wasted. I ran an Isuzu pickup for 5 years for 150k miles at 12k oil changes on synthetics just to prove it could be economical. I currently run synthetics on my street vehicles but I don't worry too much about when the oil change is due. I'll get to it "whenever".

[Sparks280zt]

Anyone seen the aftermarket centrifugal oil filtration setups they use on semis? They spin the oil at 3000g and this forces the heavier soot to the outside of the filter housing where it sticks. Supposedly filter to one micron, and there is no replacement, just open it up and scrape out the sediment that comes out of the oil. The additives in the oil need to be replenished every once in a while with the addition of a couple fresh quarts, but the oil could be used for over 100,000 miles according to the info I was reading a couple years ago. I guess the problem is that they require too large a capacity and too much oil pressure to be effective in passenger cars.

 

my dad has the unit you are talking about installed on some of his semis, its kinda pricey but since semis take over several gallons of oil, it adds up

[Afshin]

It's funny, so many people dump out good oil at 3000 miles but then use a cheap Fram filter. Spend the money on a good filter (I get the K&N), good oil and then make full use of it. Not that I have the nerve to keep the oil for 8-10K miles.

[john kosmatka]

I use amsoil oil and filters in my saab 9000, 282k miles and going very very strong.

[Guest bastaad525]

yeah I know that the 'myth' really isn't even perpetuated any more by anyone but companies like Jiffy Lube. Though regular companies like Castrol don't really seem to recommend ANY service interval? The fact that dealers started only requiring 5000-7500 mile services was the tip for me though.

 

I agree it's funny that Mobil just started marketing these 'extended service' sythentics. They charge a bit more for the 5000, 7500 and 15000, even though this test showed that just the 'regular' Mobil 1 was good to 12000... Like you said it's like they are just now marketing this 'new formula' but it's probably the same thing Or that they're just now advertising something we've always known about.

 

I have always made a habit of changing the mobil 1 in my Z at between 5000-6000 miles, and am glad to hear I seem to have the right idea . Even now, knowing about this guys tests, you guys pointed out the thing I'm most worried about, which is that I do run rich, and I do usually let the car warm up every time I drive it (extended idling while cold = fuel wash on the cylinder walls)... so I'd rather stick to 5000 miles to keep excessive fuel out of there. I always run the Mobil 1 filter as well, and have taken to 'preaching' an anti-fram statement to anyone who will listen I do wish I could find more info on other filters though as the Mobil 1 is expensive ($10-15 each) and I'll bet there are others that work as well for less dough.

 

Amsoil does look better and better the more I learn about it, though I did NOT like the fact that during this guys testing it kept thickening up, going from a 5w-30 to effectively a 15w-40 by the end of 14,000 miles. Otherwise it seemed to hold out better than the Mobil 1 by a slim margin.

 

I may try that stuff on my next oil change if I can find it conveniently, find a local dealer or something.

[preith]

It's funny, so many people dump out good oil at 3000 miles but then use a cheap Fram filter. Spend the money on a good filter (I get the K&N), good oil and then make full use of it. Not that I have the nerve to keep the oil for 8-10K miles.

 

There's a good study on filters that most of you have probably already seen, but here's the link: http://minimopar.knizefamily.net/oilfilterstudy.html

 

Unfortunately K&N was not included in the research, and that one I'd really like to know more about. IMHO Ford Motorcraft are one of the better bangs for the buck.

[Pop N Wood]

The "cheap Fram filter" is another urban legend IMO. I have read the "study" above and think most people misinterpret it. There is something to be said for evaluating a product because it "looks well made". But that is not really what I am worried about. What I worry about is how well it filters the oil, and that "study" doesn't begin to address that issue. They even say as much.

 

What it did point out is the check valve on the low end Fram is probably not up to the task. This is particularly important with my Toyota 4 cylinder truck which has been reported to have valve train problems that are exasperated by the oil passages draining when the engine is off. For that reason I switched to the mid grade Fram filters (Tough Guard) which, incidentially, the "study" above seemed to think well of.

 

People need to look past the advertising misinformation and learn that brand names don't necessarily equal better performance. Some times all it means is more expensive. Also the "more is better" is not always true either. Changing synthethic oil every 5000 miles on a street car probably does nothing more than waste money and further pollute our landfills.

 

My 2 cents.

[preith]

I agree, but he does have a link on there from an actual Fram engineer who felt their filters weren't up to snuff and vowed never to use one again.

[Guest bastaad525]

I agree, but he does have a link on there from an actual Fram engineer who felt their filters weren't up to snuff and vowed never to use one again.

 

 

Now THAT is the only advertisement I need!

 

 

Seriously though I've been somewhat skeptical of the "Fram are junk" thing too but really, it doesn't matter, I love and have heard only good things about the Mobil 1 oil that I use, and have seen tests somewhere on the net that showed their filters were good as well... I'd rather be safe than sorry. Fram might be great but if so many people think they are not there is probably a reason behind that.

 

I tend to follow whatever people that race are doing. Those guys abuse their cars so much, I tend to believe they really know what works and what doesn't. Not a lot of guys that race that I know of, are running fram filters on their cars they almost all do run synthetic oil in their entire drivetrain so I'll follow that lead for sure.

[BillZ260]

I find it interesting that Scottie is changing his filters regularly and leaving (Most) of the oil in for longer periods. Makes sense to me, but my wife just bought an Acura TSX and the OC intervals are 10K but the filter interval is 20K, even for the first one! I really want to get under that car and change the filter but she won't let me touch the car...

 

What do you all think?

 

Oh, and Fram is probably ok, there may be better, but I've got 120K on the clock on my Explorer and don't use any oil and still have great compression. I like Fram cause they put the rubber coating on the end