[ENINTY]

Just over every 17,000 miles.

[E90330iS]

7500k!

[Samuel L Jackson]

Around 7000-8000 miles. I just use the OEM stuff.

[742]

Originally Posted by redfred18t

Hey everyone I just realized I'm coming up on almost 4k since my last oil change. I just got the car recently and had the oil service done for free under the free service maintenance. Anyways my concern is that the 15k inverval is way too high. What do you guys normally do, every 3, 5, 15, etc? I'm thinking 5k because that was what I did with my vw (with synthetic) and I never had an issue.

I also own a VW which is running on a 5,000 mile oil change interval. However the oil capacity of the VWs is generally smaller than BMWs, so if all else is the same the oil change interval for the BMW should be longer.

[VWtoBMW]

Originally Posted by DarkRyan323

Under warranty: once/year or when the CBS system calls for it.
Out of warranty: every 7,500 miles or 1 year.

I would disagree with this for anyone who plans to keep a car for a long time. Even during the warranty period it would be more beneficial to change the oil more frequently while the engine is in top shape. Bumping up the intervals later will not change the fact that the long intervals during warranty created marginally more wear.

[F32Fleet]

Originally Posted by 742

I also own a VW which is running on a 5,000 mile oil change interval. However the oil capacity of the VWs is generally smaller than BMWs, so if all else is the same the oil change interval for the BMW should be longer.

Well you are running a 4-banger no?

[742]

Originally Posted by Socom

Well you are running a 4-banger no?

Yes, and you got me to go look it up. The bigger engines do hold more than I thought (the V6 Passat being even larger than the E90).

So it depends. But a 5,000 mile OCI on the common 1.8T/2.0T VW/Audi would certainly equate to something much longer on an E90.

[mkPOTO]

can you go to the dealership and ask them to do it without being charged? anyone able to do that?

[Tegs4tugs]

I do mine at every 5k but im running stock would recommend more frequent if you drive very hard with mods.

[carve]

About every 6500 miles. I would do it a little more often, being a high-strung turbo engine, but this thing holds 7 qts. That's a TON for a 3L engine...4 or 5 would be more typical on an American or Japanese 3L car. I think that extra capacity makes it last that much longer between changes. 7 qts vs 5 is 40% more, so all else equal you could go 40% longer between changes. 6500 miles would be like 3900-4500 miles on 5 qts (depending whether you consider 5 29% less than 7, or 7 40% more than 5)

My CBS Indicator had me on track to go 25,000 miles between changes! No friggin way! These are mostly city miles, too.

Question though: with changes this frequent, is it necessary to get the expensive LL01 oil, or can I just use Mobil1 5-30?

[F32Fleet]

Originally Posted by carve

About every 6500 miles. My CBS Indicator had me on track to go 25,000 miles between changes! No friggin way! These are mostly city miles, too.

Question though: with changes this frequent, is it necessary to get the expensive LL01 oil, or can I just use Mobil1 5-30?

The CBS should modulate, from my own experience it stays high for a long time and then takes a precipitous(sp?) drop once you hit ~15k miles.

Something to keep in mind is that you're still entitled to a oil change once a year which makes the whole "CBS says 25k miles" moot. The dealership won't reset the CBS, and you really don't want them to.

IIRC part of the requirements of the LL01/LL04 rating is extended drain intervals. I would guess that you could run any similar weight oil made for turbocharged engines if you're going to change that oil every 3k-5k miles.

[vietmike101]

how i do i check the service interval?

[Wosby]

every 7500 miles with full synthetic = once on my own between every BMW scheduled service.

[Chriztofor]

15,000 miles and 7500 miles for oil filter changes. I did that in my e46 for 184,000 miles using mobil 0-40 and when I replaced the valve cover gasket the head was clean no sludge build-up.

[jaguar36]

I ran my E46 with the ~15k interval for 120k miles and never had a problem.

Has anyone seen any hard data that correlates oil change interval to engine problems? Or is everyone just going on the 3k/5k interval based on what they were told 20 years ago by the people who make money on oil changes?

[bimmertt]

question...why is there a time interval? does they oil break down over time even if mileage is kept down?

[Alan@PYSpeed.com[retired]]

7500 miles for my car.

[742]

Originally Posted by jaguar36

I ran my E46 with the ~15k interval for 120k miles and never had a problem.

Has anyone seen any hard data that correlates oil change interval to engine problems? Or is everyone just going on the 3k/5k interval based on what they were told 20 years ago by the people who make money on oil changes?

There have been a number of brands/models/engines in recent years that have had significant oil related issues. Some of them German. That does not mean that the N51/N52/N54 will have problems, but it is not irrational to look upon 15,000 oil change intervals with a jaundiced eye -- especially in colder climates or with a car that does short trips. Unfortunately it will take some time for problems, if they exist, to show themselves. It took about 7 years for the VW/Audi 1.8T issue to surface, as one example. And interestingly that problem was unique to the North American market, so what works in Europe does not necessarily work everywhere.

So maybe I am wasting money with my cautious approach with my wife's E90. On the other hand I probably saved myself a lot of grief with my cautious approach with her Passat.

Of course the best approach is systematic oil analysis, which very few people seem to be doing.

[742]

Originally Posted by cgtsx07

question...why is there a time interval? does they oil break down over time even if mileage is kept down?

The oil's ability to combat acids is more or less time based. It is not that the oil itself breaks down, but the ability of the oil additives to neutralize acids deteriorates which leads to corrosion.

That Europe can go two years while BMW only allows one year for North America is a testament to the quality of our gasoline.

[bimmernoob]

Originally Posted by 742

The oil's ability to combat acids is more or less time based. It is not that the oil itself breaks down, but the ability of the oil additives to neutralize acids deteriorates which leads to corrosion.

That Europe can go two years while BMW only allows one year for North America is a testament to the quality of our gasoline.

What does this mean in terms of the oil's shelf life? Meaning, if the oils is new in the bottle, does it still have the 1 year "goodness" limit? Or does the time limit only matter once the oil is out of the bottle?

[742]

Originally Posted by bimmernoob

What does this mean in terms of the oil's shelf life? Meaning, if the oils is new in the bottle, does it still have the 1 year "goodness" limit? Or does the time limit only matter once the oil is out of the bottle?

5 years in the bottle is, I believe, the general guidance for oils.

A product of combustion is water, and water also gets in the oil by simple condensation as the engine heats and cools. Add the combustion products that get by the rings, including the sulfur that is in gasoline, and you have acid.

What we need on the forum is a chemical engineer...

[bimmernoob]

Originally Posted by 742

5 years in the bottle is, I believe, the general guidance for oils.

A product of combustion is water, and water also gets in the oil by simple condensation as the engine heats and cools. Add the combustion products that get by the rings, including the sulfur that is in gasoline, and you have acid.

What we need on the forum is a chemical engineer...

Thank you for the info!