Extended Oil Change Intervals and other junk

[DominoTree]

I've been hesitant to post a question in here because I'm sure it's been answered a ton of times before, but I have several questions about oils that allow extended intervals between changes and some other stuff as well...

My first question is, with modern high-quality oils claiming to be safe for 15,000 mile intervals and beyond - is it safe? Would I be causing reliability problems down the road? I know that vehicle reliability is based mostly not on the oil I use but how I drive and how often I change the oil.

Second of all - what oils would have the longest intervals? I read somewhere of a 25,000 mile rated Amsoil synthetic.

Third - I live in a somewhat dusty environment. Should I be concerned about changing my oil more often? I've been using a K&N air filter but I think I'll be removing it because of the high level of particulate matter they let through, and I've been using both Mobil 1 EP with a M1 EP Filter and changing it at 10000 instead of 15000 miles and Royal Purple with a K&N oil filter and also doing it at 10000 miles rather than 12000.

Fourth and final - When it is time for an engine rebuild, what oil should I use to help prevent sludge buildup... I hate cleaning parts

Thanks for any insight you can give.

 

[Quest]

LOL!

If you operates your vehicle in an environmentally adverse environment, do yourself a favour and reduce your OCI to the "severe" service level and stick with it.

Also: I'm not a big fan of K&N in dusty environment and I would suggest you to go back to factory paper element air filters instead.

You cannot extend your engine's life by subjecting it to such harsh operating environment and want to extend your OCI level past "sensible" level.

Go with dino oil such as Castrol GTX, Havoline, Chevron, etc. and get it down to approx. 5000miles OCI.

My 2c's worth.

p.s. if you question me why I would recommend such drain interval, it's because you need to flush out the dirty oil that trapped the dust that gone past your K&N filter.

 

[ATS-V]

Welcome.

It depends on you type of engine and driving conditions. The only way for sure to know what your engine likes is a used oil analysis (UOA).

My opinion on this, unless your driving lots of highway and have a engine that's easy one oil, I think 15k is way too much for 90% of cars.

 

[hominid7]

Call me old fashioned, but i'd be hesitant to let my oil go beyond 5000 miles. Most UOA's i've read in the UOA section seem to indicate in "most" instances, 4000-6000 miles tends to use up an oils additives and base number.

Certainly with add-on filteration systems and true full synthetic oils, longer OCI's are possible without harm, but in most regular cars running regular dino or semi-synthetic oils, 5K seems to be a good and (mostly) well agreed upon number around here.

In all instances i've ever seen where cars have made the magic 500,000 mile mark or beyond, the type of oil may differ, but one thing remains constant, that regular and frequent oil changes are always a part of the equation.

Now big-rigs regularly run VERY long OCI's with VERY high mileage success. They however are operated under a different set of circumstances, lots of highway miles, massive filters, and sae 15w40 severe duty oil in the mix.

Most owners manuals tell you that city driving, dusty conditions, towing, long idling, mountain driving, etc are all circumstances where the 'severe duty' oil change interval should be followed.

As far as what oil will keep your engine clean? Thats a can of worms, but from my non-scientific experience it would seem that most any oil meeting your cars requirements will suffice. Long life extended drain synthetics can and will keep an engine cleaner than a dino given the same set of circumstances and same miles driven, but at twice (or more) the cost. For me, the cost-per-mile, given my driving conditions makes synthetics of less overall value than regular dino and blend oils.

Keep in mind the two cars that have documented over 1 million miles both have 1 thing in common, they both used inexpensive regular dino oil, and changed it often. Oil is only part of the equation though. Regular maintenence of other engine and cooling systems is a big factor in keeping your car running right. Plugs, wires, PCV, gas filter, etc... all factor in to how much waste your oil has to fight.

On the other hand, there have been some engines that are prone to sludge build up due to bad design. That's not the oils fault though. If you are lucky enough to own one of these gems, using synthetic, changing it more often may make sense.

In addition whatever you drive and whatever oil you use, be sure to follow at least the minium OCI in the owners manual to keep your warranty valid.

 

[Patman]

Quote:

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Now big-rigs regularly run VERY long OCI's with VERY high mileage success. They however are operated under a different set of circumstances, lots of highway miles, massive filters, and sae 15w40 severe duty oil in the mix.

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They also have very large oil capacity too, something I wish more car makers would do. I'm not saying that your average passenger car should have a 10 or 15 gallon supply of oil, but if they could even raise it up by 1 or 2 quarts it would make a big difference in how long of an OCI you could safely run in your car. Larger oil capacities reduce the stress on the oil, allowing for that longer OCI.

 

[hominid7]

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They also have very large oil capacity too, something I wish more car makers would do. I'm not saying that your average passenger car should have a 10 or 15 gallon supply of oil, but if they could even raise it up by 1 or 2 quarts it would make a big difference in how long of an OCI you could safely run in your car. Larger oil capacities reduce the stress on the oil, allowing for that longer OCI.

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Very good point. My old Mazda Protege has less than 4 qt sump which made me uneasy to say the least!

 

[DominoTree]

I've got a 2003 Ford Escort and just by date I'd already exceeded the warranty (and now by miles - just got 54,000 miles on it)

I used to drive nearly 200 miles a day between various offices, most of it city miles, but nowadays it's closer to 50, and it is quite a dusty climate.

The reason I was using the oils previously was because I needed to change my oil every two weeks otherwise, but the more I think about it, it's not more than a 20 minute job, and now that things are slower, it will be several weeks between changes.

That being said, I'd still like to run a full synthetic with a high moly content and good filters even if I am doing changes every 3000-5000 miles.

 

[TimVipond]

DominoTree - with the dusty road conditions, you fall into the severe mileage catagory. With AMSOIL you can go up to 17,500 miles/1 year with their 0W30 oil, 15,000 miles/1 year with their regular oils and 7500 miles with their XL line. You can use any filter with the 7500 mile oil, but need to use the AMSOIL filter if you only want to change the filter when you change the oil with the other two oils. I also suggest getting the AMSOIL EaA reusable dry nanofiber filter. Just vacuum it of when you think it is dirty, normally around 25,000 miles. Sooner with dusty roads. Parts and labor are warranted should any of the AMSOIL products fail.

For all other oils you should follow the severe use oil change interval recommended in your Owners Manual. This is usually around 3,000 miles.

You can immediately use AMSOIL products following an engine rebuild.

I can give you more specific info if you let me know year/make/model/engine of the vehicle.

 

[TimVipond]

For your Escort: AMSOIL does not make the EaO filter, but do have a WIX Oil Filter #51315. You would need to change this every 7500 miles. Engine oil recommended is: Engine Oil
Grade 1......API*
SAE 5W-20 XL Synthetic Motor Oil (7500mile/6 months severe)
Series 2000 Synthetic 0W-30 Motor Oil (17,500 miles/1 year severe)
All Temps......5W-20[1]1. Use Ford part no. XO-5W20-QSP or equivalent
motor oil meeting Ford specification WSS-M2C153-H. Air filter is WIX #46406 and should be changed out according to your owners manual.

 

[B00SS]

Well, I’ve been beaten to the punch, but UOA’s are essential to extend drains as far as you’re talking about. With UOA’s you may find you can go longer or not quite as long, but either way you’ll have the piece of mind you decisions are based on more than just someone’s guess. They will even give you insight as to that air filter. My guess would be to not use the K&N in a dusty environment, but again, use the science to know for certain. Wanting to use extended OCI’s, you will be using the synthetics which should help keep the sludge down anyway. If you change the oil often enough (see the UOA comments) you shouldn’t have sludge to worry about anyway. Welcome to our humble hobby, enjoy.

 

[boxcartommie22]

no matter what oil you use synthetic or mineral city driving is severe service and your oil and filter should be changed every 3000 miles or 3 months..garbage still gets in the oil and acid build up...the companies that say an extended oil change is nothing but letting you know their oils will live up to their severity and inc. oil changes... imho,its better for you and vehicle to stick with the 3000 mile and 3 months interval..

 

[Lonnie]

Longer oci's are just a bet. You're betting that cutting down on changes and saving the cost of a change won't effect the vehicle while you own it. The oils are here to do it, but there is one thing that is missing from many cars. It's a simple thing for the manufacturer to solve but as an owner you're stuck. That one change? Sump capacity. If you 2 litre turbo wizebang engine with a 4 quart capicity just went to 6 quarts I think it would help with longer intervals. But as it stands, the manufacturering of cars is a game of making something that is just good enough and no better. Here in lies the path to greater profits, good enough is good enough.

 

[DominoTree]

I've really been thinking about a UOA - how much will it run me and who should I go to? I'd like to see what condition this royal purple currently in my motor is in - it's got just over 7000 miles on it now, was planning on running it to 10 but I'm scared to do so now

The more I think about it, if I am just gonna do 3000-5000mi service intervals, is there any serious benefeit to going with a full synthetic, or would I be just as good going with Castrol GTX and a Purolator

 

[Patman]

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Longer oci's are just a bet. You're betting that cutting down on changes and saving the cost of a change won't effect the vehicle while you own it. The oils are here to do it, but there is one thing that is missing from many cars. It's a simple thing for the manufacturer to solve but as an owner you're stuck. That one change? Sump capacity. If you 2 litre turbo wizebang engine with a 4 quart capicity just went to 6 quarts I think it would help with longer intervals.

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I agree, I've said this before many times (and even mentioned it in this thread too)

As owners, we are stuck somewhat, although we can take matters into our own hands by finding bigger oil filters that will fit our engines, as well as overfilling the engines a little bit as well. With some engines it is totally safe to add an extra 1/2 quart or even an extra full quart! In my Corvette's owner's manual, GM even recommends adding an extra quart if you're racing it. And the way I see it, if the engine can handle the extra quart, then I might as well run it that way all the time. With my wife's Civic, I've been adding an extra half quart for a long while now. A half quart extra is more than a 10% bump in capacity on that engine. So in theory that might mean I could extend the intervals by 10% more than if I ran the lower specified amount of oil.

 

[TimVipond]

I think any of the site sponsors can get you a Used Oil Analysis kit. I know the AMSOIL ones can. Site sponsors are listed at the top of the main page.

 

[Patman]

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I've really been thinking about a UOA - how much will it run me and who should I go to? I'd like to see what condition this royal purple currently in my motor is in - it's got just over 7000 miles on it now, was planning on running it to 10 but I'm scared to do so now

The more I think about it, if I am just gonna do 3000-5000mi service intervals, is there any serious benefeit to going with a full synthetic, or would I be just as good going with Castrol GTX and a Purolator

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An oil analysis will run you roughly $20, and Blackstone is one of our sponsors here and would appreciate your business.

If you're only going to be doing 3-5k intervals, there is really no need to be using synthetics, unless you live in an extremely cold climate, or own an engine that needs it (such as a turbocharged engine for example)

 

[DominoTree]

I put in 5 quarts of motorcraft oil and a motorcraft oil filter, and a cheap paper air filter, got the RP in a clean container, i'll get it sent off to blackstone and see what they have to say about it

 

[Gary Allan]

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Call me old fashioned, but i'd be hesitant to let my oil go beyond 5000 miles. Most UOA's i've read in the UOA section seem to indicate in "most" instances, 4000-6000 miles tends to use up an oils additives and base number.

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This I don't quite agree with blindly ..not at all (more later)

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Certainly with add-on filteration systems and true full synthetic oils, longer OCI's are possible without harm, but in most regular cars running regular dino or semi-synthetic oils, 5K seems to be a good and (mostly) well agreed upon number around here.

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The reason that it appears to fall into that number is because many are old fashion like yourself

and don't go over 5k on an oil change. The other is that the VAST majority of us are way beyond being "soccer parents" and aren't carting kids all over heck and gone.

What you see as a 4-6k OCI may very well be 6 months but just isn't expressed that way. 6 months time will, perhaps, tax the TBN due to trip length and seasonal shifts in temp.

If you see someone doing 15k-20k a year doing 5k OCI ..with a few exceptions ..they're wasting oil. Someone doing 10k a year doing 5k OCI probably isn't.

Quote:

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In all instances i've ever seen where cars have made the magic 500,000 mile mark or beyond, the type of oil may differ, but one thing remains constant, that regular and frequent oil changes are always a part of the equation.

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Anyone who puts 500k on the same engine untouched had to take better care of their car in general ..and, most likely, did some very easy miles on their engine. Even EXCEPTIONAL (25k/year) would take 20 years to reach that finish line. 25k/year has the vast majority of the operational life of the engine in the lowest wearing part of the curve. It's also far less stressful on oil. The fact that frequent oil changes were done may or may not have had much to do with the longevity of the engine. That is, if they changed it every 1000 miles ..you may say that it was excessive ..but since whatever that person did in their reaching 500k worked ..you've assumed that their number was essential ..if you see what I mean. If they had done it half as often ..they may have still succeeded

 

[Titan]

UOA's suggest to me that 8000 miles on Pennzoil Platinum in my Subarae (that's two subaru), is well within the saftey zone for those cars on that oil under the conditions they are operated. O have lower than average wear values on engines with HALF that mileage on the oil. So, it depends...you won't know for sure until you spring for at least a 20.00 UOA.

 

[TimVipond]

Titan - if you go to the Pennzoil Platinum website, you are doubling the oil change interval that they warranty for. Just so you know.