How far can you really go between oil changes (using conventional oil)

[LTC8K6]

Doing 15k is fine for most BMWs and their image as they have larger sumps and also require Syn oil.

That's what I said...

They aren't trying to save money with 15K intervals.

 

[railer]

That's what I said...

They aren't trying to save money with 15K intervals.

But I'm sure they'd be willing to sustain 10's of millions of dollars in lost revenue due to their destroyed reputation in order to save a few bucks on longer interval oil changes.

Not.

And I guess we've just given up on trying to explain why every other auto manufacturer also recommends longer interval oil changes, even though they DO NOT offer free maintenance?

How many miles can a CPO car have? Like 30k max? Not 100k that's for sure. They want you in a new car long before you hit 100k. And most people have no idea what an oil analysis is. Here is one that showed badness at 15k
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=219281

That's not a bad oil analysis (TBN = 1.5), and that thread (and that oil) is 10 years old!

 

[Fritzo]

That's what I said...

They aren't trying to save money with 15K intervals.

Yeah, mine take 7.9qts of full synthetic and 15K from normal driving is recommended. What's cool though is the oil filter is on top of the engine, so you can just connect an extractor to your oil dipstick nozzle, suck out all the oil, and then replace the filter + oil.

10 minute oil change without having to get under the car

 

[Throckmorton]

But I'm sure they'd be willing to sustain 10's of millions of dollars in lost revenue due to their destroyed reputation in order to save a few bucks on longer interval oil changes.

Not.

And I guess we've just given up on trying to explain why every other auto manufacturer also recommends longer interval oil changes, even though they DO NOT offer free maintenance?



That's not a bad oil analysis (TBN = 1.5), and that thread (and that oil) is 10 years old!

Probably to keep up with the Joneses. The interval for my 2006 Mustang with 6qt is 5000mi, and Ford increased that in 2007 to 7500mi. Those are reasonable intervals to me but I think 7500mi is pushing it if you drive your car hard. So what is it about a BMW or a Honda that allows them to go much further?

 

[Jimzz]

But I'm sure they'd be willing to sustain 10's of millions of dollars in lost revenue due to their destroyed reputation in order to save a few bucks on longer interval oil changes.

Not.

And I guess we've just given up on trying to explain why every other auto manufacturer also recommends longer interval oil changes, even though they DO NOT offer free maintenance?



That's not a bad oil analysis (TBN = 1.5), and that thread (and that oil) is 10 years old!

What other makers OK with 15k? Most I have seen are 10k-ish and I am fine with that if Syn oil is used.

 

[JCH13]

What other makers OK with 15k? Most I have seen are 10k-ish and I am fine with that if Syn oil is used.

Mini is something like 12k/1yr or so the last time I checked.

Oh wait, that's BMW again...

 

[hans007]

Mini is something like 12k/1yr or so the last time I checked.

Oh wait, that's BMW again...

BMW isn't a specific interval . The computer just says so. For my car I think it'll end up about 11k but I drive a super urban type cycle

 

[Jimzz]

Mini is something like 12k/1yr or so the last time I checked.

Oh wait, that's BMW again...

Big differance between 12k and 15k.

Some cars may be able to pull off high mile oil changes but saying all cars can would be false. Of course I call BS on the 3000mile/3month oil change for most cars as well. But I agree once a year is good measure.

 

[Baked]

I used to do 3K. Then I realized I'm just driving the city majority of the time with some highway mixed in, and it's a waste of money changing so often. So I switched to 5K per change with synthetic, per my car's owner's manual.

 

[JCH13]

Big differance between 12k and 15k.

Some cars may be able to pull off high mile oil changes but saying all cars can would be false. Of course I call BS on the 3000mile/3month oil change for most cars as well. But I agree once a year is good measure.

Re-looked-up the Mini OCI, it is indeed 15k/1yr.

 

[Jimzz]

Re-looked-up the Mini OCI, it is indeed 15k/1yr.

That makes more sense being that it is owned by BMW.

I can see some drivers getting 15k out of a BMW due to the large oil sump and syn oil but I think most minis hold 5qts? If so I would not run 15k on that.

EDIT
Just looked at some mini sites and most change at 5k-10k.

 

[overst33r]

41k oil change interval

http://www.s2ki.com/s2000/topic/1021029-uoa-after-41k-oci-at-272000-miles/

 

[Throckmorton]

41k oil change interval

http://www.s2ki.com/s2000/topic/1021029-uoa-after-41k-oci-at-272000-miles/

I don't get how the prelube oil pump makes a 41k oil change interval possible

 

[Jimzz]

I don't get how the prelube oil pump makes a 41k oil change interval possible

Its not, its the extra oil he has to add and larger amount the car holds now due to mods is what keeps the oil alive...

"With 10 makeup quarts in ~40k miles, that's like adding a quart every ~3,500 miles."


A good group 4 Syn oil and adding a qt to freshen it every 4k will help a lot. That and the larger dual filters and extra amount of oil in the system also helps.

 

[slag]

Amsoil has an oil and filter combination they claim will get 25k miles between oil changes.

So, 25k miles is the answer.

 

[LTC8K6]

Amsoil has an oil and filter combination they claim will get 25k miles between oil changes.

So, 25k miles is the answer.

Would that be with conventional oil, the subject of this thread?

 

[Throckmorton]

Its not, its the extra oil he has to add and larger amount the car holds now due to mods is what keeps the oil alive...

"With 10 makeup quarts in ~40k miles, that's like adding a quart every ~3,500 miles."


A good group 4 Syn oil and adding a qt to freshen it every 4k will help a lot. That and the larger dual filters and extra amount of oil in the system also helps.

Why does he keep having to add oil?? Where is it going?

 

[JCH13]

Why does he keep having to add oil?? Where is it going?

Around the rings, through valve stem seals, aerosolized and sucked out the PCV system, out of any small leaks...

Dude has an engine with 277k miles on it, it's going to burn some oil.

 

[Throckmorton]

Probably to keep up with the Joneses. The interval for my 2006 Mustang with 6qt is 5000mi, and Ford increased that in 2007 to 7500mi. Those are reasonable intervals to me but I think 7500mi is pushing it if you drive your car hard. So what is it about a BMW or a Honda that allows them to go much further?

BTW that 5000mi/7500mi interval is with semi synthetic not conventional

 

[Throckmorton]

Around the rings, through valve stem seals, aerosolized and sucked out the PCV system, out of any small leaks...

Dude has an engine with 277k miles on it, it's going to burn some oil.

With his prelube system I'd expect those 277k miles to be equivalent to many fewer miles on a normal car, since 90% of wear happens at startup!!

 

[Throckmorton]

Here is an explanation of the differences between mineral and synthetic oil http://www.bobistheoilguy.com/motor-oil-103/

Mineral oil is based on the W weight oil, with additives to maintain thickness at higher temperatures. Those additives break down and the oil gets thinner with use. Synthetic oil is the opposite, it's the 212F weight and just doesn't thicken as much at colder temperatures. It doesn't need additives for that.

 

[JCH13]

With his prelube system I'd expect those 277k miles to be equivalent to many fewer miles on a normal car, since 90% of wear happens at startup!!

Does he say that the oiling setup has been on since new?

Do you have a reliable, technical source that says "90% of wear happens at startup" at the exclusion of abrasive particles in the oil, corrosive/acidic byproducts that wind up in the oil, warm-up conditions, etc?

Smart make with the brain thing and don't jump on board with every common assumption you read.

 

[overst33r]

Why does he keep having to add oil?? Where is it going?

Early S2000s are known to burn oil by design. Mine does nearly 1qt/1000mi. Perfectly normal.

 

[Throckmorton]

Does he say that the oiling setup has been on since new?

Do you have a reliable, technical source that says "90% of wear happens at startup" at the exclusion of abrasive particles in the oil, corrosive/acidic byproducts that wind up in the oil, warm-up conditions, etc?

Smart make with the brain thing and don't jump on board with every common assumption you read.

I think he said he installed it around 25k.

Bob Is The Oil Guy says 90% of wear occurs at startup, because oil hasn't started pumping yet and because it's still cold. I'd think that prelubing would reduce that substantially

 

[JCH13]

He installed them <6k after new, if you bothered to read the first two sentences in his first post in his BobIsTheOilGuy thread. I can only surmise that the 25k mile number was rectal-plucked on your part.

"On 5/30/04, I installed an Amsoil BMK-13 Dual Remote Bypass Filter and a prelube pump on my &#8217;03 Honda S2000. I did a great deal of research on oil filtration systems before I came up with this setup. My car had 5,997 miles when I installed it."

It would seem he's burning oil at less than 1/3 the rate of a typical S2K, if the 1qt/1,000mile number is accurate and he is indeed only adding 1qt every 3,500 miles.

So, one should conlcude from this information that his setup of prelube pump, oil filters, and selection of AMSoil 0W30 is a very good one.

Can you please link to where BobIsTheOilGuy states and proves that 90% of wear occurs at start-up?