Thoughts on running synthetic for longer periods?

Hey all,

I'm curious to hear some of your thoughts on running synthetic for extended durations. I've been running Mobil-1 Extended Performance Full Synthetic for ~12-15k, while changing the filter ever 3k miles. I add a little bit every time I change the filter, just to offset the little bit of oil that drains when the filter is pulled.

I've been told that the synthetic is fully capable of lasting this long, but I'd love to hear your input. The oil is always dark after the first 3k, but I'm not really certain that this is a good indication of oil life-cycle. I've had oil "tested" and it showed that it was still at viscosity.

 

Your question is a highly debated topic......and it varies.

I change mine at regular intervals (4500-5000 miles on my 07). The oil is really dark which means its 'dirty'. Regardless of how good the oil might still be - I'm perfectly happy changing it and getting rid of the dirty oil at regular intervals.

 

I understand that it is controversial... still looking for input.

I've never personally run an engine past 110k miles, but I'd like to keep my Tacoma for a long while. I'm curious if anyone has run synthetic as per my method above with long-term success.

The question really came up since I'm due to change my wife's Rav4. Unfortunately, the filter is internal and I will be forced to drop all of the oil to change it. To continue changing oil the way I have for years, I would have to remove her oil, and pout it right back in... which just seems incredibly messy. I prefer to run synthetic oils, but the cost is significantly higher if I simply change her oil every 5k.

 

i know this is kind of different. but semi trucks (i work on them) the run alot of miles with their engine oil they can do this because they change their filters but also think about this some of ours hold 38 courts ~ but each filter is about 1-1.5 gals so they can do that and add a good amount of new oil. you should get oil samples and send them out to get examined to see if your oil is doing its job and all. and i know mobile one make extended performance oil that is supposed to last 15000 and it is synthetic i use the normal synthetic on my truck and change at 4000 because thats when i think it needs to be changed

 

I ran synthetic in my previous car (Chrysler Pacifica). Routinely reset my 5k oil change warning to where I would change it on the second (10k) or third (15k) time it came on.

I traded it in with 130k miles or so on it. But yes, it is a highly debated topic on any automobile forum. Good luck

On my Tacoma I plan on changing it every 5k for now, since I got it brand new and I like changing the oil on this beast.

 

My thought is this....

Convential oil plus filter every 3,000 miles=cost $35.00

MobilOne plus filter every 6,000 mile=cost $70.00

Having to change my own oil half as often for the same cost..... Priceless.


Not a Sermon, just a thought.

 

This topic might go crazy, but one thing to keep in mind

conventional oil is rated for 3000mile intervals because thats when it starts to break down
synthetic breaks down is far past 3000mile depending on which one

Your oil might "look" dirty just miles after an oil change, just by "looking" at an oil doesnt tell you its broken down, but particals are of course ---> obvious

 

Walmart man! 5quarts Mobile1 synthetic for $21

 

^^Well said, I change my synthetic every 6,000 too. It equals out to the same price as conventional oil with better wear protection and fewer oil changes. I personally wouldn't let it go past 6,000.

 

If you really want the answer to your question, send your used oil to Blackstone labs for an Oil Analysis. I think it'll cost $25; but that way you'll know how your oil is holding up. Personally, I'd go with a longer life filter (Mobil 1, PureOne, Bosch Advanced Guard, K&N) and run them both for 10K mi intervals.

 

You oil will litterally never wear out.... synthetic could go 100K miles. Your additives that inhibit corrosion, suspend carbon, and neutralise acids will get used up. To see when these wear out you need to do engine oil analysis. The filter just grabs all the stuff the additives cling to. When it gets full your filter will get bypassed. The only way to know is to check your oil and find out when YOUR truck needs the oil changed with YOUR use and in YOUR area. The oil itself will lubricates fine at any milage.


Conventional oil can go bad in 30 days and under 1000 miles in the right conditions or it can last thousands of miles ad months. Its much less stable with changes in temperature, exposure to contaminants, etc. It also changes viscosity... synthetic not so much. Viscosity in synthetic is NOT what you want to look at for when to change oil. For regualr oil the increase in viscosity is a real problem.

 

Thanks all.

Not trying to start a debate... but there is a lot of useful information here.

Unfortunately, I'm having a tough time finding a high-mileage filter for the Rav4 w/ V6. If anyone has some information for me, I'd feel much more confident with running the oil for an extended period with a better filter.

 

eltaco,
Take a sample of your oil at 5k miles and send it off for an analysis at a place like http://www.blackstone-labs.com/?gclid=CLrE4baOq6MCFRCenAodtRKK3g
Otherwise you are just guessing and probably wasting oil and money.
Any good dino much less the syn oil should be good for at least 5k. If the oil is "worn out" at 5k then you probably have engine problems which the oil test should help you determine the problem.

 

Thanks, I think that I might do just this.

I used to run a full-synthetic by "Conklin" as a fellow I knew at the time sold their product. After 12k miles, the oil tested fine on his personal tester. Unfortunately, I don't know what it was testing for, but I assume there was some validity to it. I should also mention that my vehicle at the time was a '77 Ford F150, so a little bit different of a beast from today's technology.

That being said, it was a different brand of oil in a different vehicle, in different driving conditions... almost nothing can be held constant between the two scenarios. It did, however, open my eyes to the capabilities of synthetic lubricants. It does seem when I ask around locally that I'm one of the only people running oils as long as I do, which tends to concern me a bit... I was very curious what some of you are doing, and if any known issues have come of extended-mileage oil changes with synthetics.

 

Had a YJ from 85,000 to 189,000 ran Quaker State 4x4 Syn Blend. Had pretty much the same power I bought it with. Changed oil every 3,000 to 5,000 miles. With current vehicles, unless it's a turbo, every 5,000 to 6,000 miles is plenty often enough and not that expensive.

I wouldn't go 10,000 to 15,000 unless I have a 10 qt oil reserve and a huge filter. Mobil 1 says you can go every 15,000 miles but I wouldn't do it.

I can still notice how much smoother the engine idles when changing at 5,000 miles. That would mean it runs rough (rough usually means extra friciton) for another 10,000 miles. It's cheap enough might as well do it every 5,000.

Just my thoughts.

P.S. Running a really good filter is imperative. Fram not so good. Try Wix or Napa Gold (Wix with Napa name).

 

All the diesel engines tht I've owned when checking the oil after 1000miles looks worse than any oil that I've ever taken out of a gas engine. Visual or oil rubbed between the fingers tells you absolutely nothing about the characteristics of the oil.

Dirty is a relative thing. For practical purposes the filter will keep the oil clean enough to do it's job. The reason to change any oil varies on several factors (viscosity, additive depletion and others) which require a laboratory to determine.

 

To repeat what some others have said, take a sample at your next oil change and send it to Blackstone Labs. Actually, you should get them to send you a sample kit before hand. In addition to the standard analysis, you might want to have them do a TBN test too. It's an extra $10, but is supposed to provide you with information about extending your drain intervals. Good thing about Blackstone is that you get a personalized report and you can actually call and talk to someone about it.

If you're using synthetic oil, it's the detergents/additives that you have to worry about breaking down and not so much the oil. Good filtration is also key. I've been using AMSoil with AMSoil brand filters and just sent in a sample that had about 14-15k miles on it. I'm not sure if they still sell AMSoil filters for all toyotas, but for the Taco now they only offer a MANN filter which is spec'd for 7500 mi. So basically 2 filters per 15k mile oil change.

Maybe look into a bypass filtration system if you're really serious about it.

 

Synthetics can run longer than conventional oils where severe conditions are the norm. Any oil synthetic or not will be rendered useless if taken past it's abilities to deal with the operational conditions. The main reason synthetics are desirable over conventional oil is that they reduce operating temps through thermal conductivity which = ability for the oil to remove heat from the working environment. There are a host of other reasons why synthetics are better that mineral oil but all that = better ability to stay with in spec fir a longer time. So yes you can go many more miles than a mineral oil if you occasionally operate past the limits of the mineral oil which will be lower than the synthetic oil.

Having said all that I've seen mineral oils go way over 500 hrs on heavy duty minig trucks that operate in conditions way more severe than anything your truck will ever see. They run 24/7 the test results come back good to continue. Also seen a locomotive engine that ran a mineral oil for several years with changing oil filters and topping off oil. At the teardown the pistons where clean as a whistle -- so much so that the customer was so impressed that he framed one of the pistons and presented it to the distributor who sold the oil.

Diatribe off

 

this is all good stuff - pardon me but I didn't read it to the nth degree but I used to work for a company that made 95% of all Class 8 truck tans coolers (Eaton supplier and supplier to every chassis manufacturer). I have seen failed (clogged coolers with less than 100,000 miles and I have seen coolers with 300,000-500,000 that ran synth and they looked brand new!

I applaud anyone that would really create a good schedule - I would be willing to paypal someone a contribution so that we can get good data. Jus' sayin'

 

I run Mobil 1 10,000 mi.