Here is our 2nd UOA. Here is the oil change history based on the odo (the MINI is currently 10 months old):

2K DIY oil + filter Pennzoil Platinum 5W30
8K UOA
12 K DIY oil + filter PP 5W30
18 K MINI Service oil + filter OEM oil 5W30, + air filter changed
27 K UOA
27K DIY oil + filter BioSyn 0W20

The UOA were both performed by Dyson Analysis.

Odo.....................8K........................ .....27K
Oil miles...............6K ............................8K
Brand...................Penn Plat....................MINI oil
Grade..................5W30....................... ...5W30

Iron ....................31............................ ....29
Copper ..............19................................11
Tin ..................... 0...................................0
Lead ...................1.............................. .....0
Chrom ................1................................. ..0
Nickel .................1................................ ...1
Alum ..................41.............................. ....12
Titan .................. 0....................................0
Silver ..................0............................... .....0
Cal .....................2205......................... .....1986
Magnes ..............286................................. 30
Zinc ....................978........................... ......1081
Phos ...................882............................ .....984
Barium ............... 0.....................................1
Moly ...................126............................ ......167
Antim ..................0............................... .......0
Silicon .................24............................... .....7
Sodium ................8................................. .....18
Boron ..................31.............................. ......55
Potass ..................0............................... .......0
Vanad ................. 0......................................0

V40C ...................55.4........................... ......67.5
V100C .................9.6.............................. .....10.6

TAN ....................4.3........................... .........2.83
Flash ................... 305...................................340
Oxid .....................27........................... ..........24
Nit ........................12........................ .............13
KF ....................... 788...................................347
TBN .....................3.8.......................... ...........2.8
Fuel ......................1.42........................ ............1.12

Soot ......................0........................... ..............0
Glycol ....................0............................. ............0

Vis Idx ...................160............................ .........147

I think the data looks pretty good. Wear metals are decreasing. Although probably not low enough for me to throw a party (what's with the elevated Fe and Al? Do I have a coolant leak?). Viscosity looks solid. Acid neutralizing ability is pretty much depleted. Fuel dilution is a little better. I think MINI/BMW Castrol oil looks pretty good compared to Penn Plat.

I think it is clear that MINI/BMW oil is a good oil, but I don't see any evidence that it can last even half the OEM recommended OCI. Get this, the MINI computer wants me to run this oil for another 12K miles I don't think so, I've replaced the oil and my wife is enjoying better MPG with the less viscous grade BioSyn.

 

Based on this analysis, how often would you recommend changing the oil from the day of ownership?

Thanks!

(I'll be getting my MCSa in september/october)...

 

Looking pretty good, but you were right to change the MINI oil when you did. Looking at the TAN/TBN, flashpoint & fuel dilution, you were just about due. Sad thing is, there was still plenty of the additive package left, so it makes me wonder how long the MINI oil could last if not for the dilution issues with our cars.

I hope your BioSyn numbers turn out as good as mine have. Just out of curiosity, what motivated the choice of 0W-20 for the BioSyn? Seems a little light for a summer oil, and appears that it's the first time you've used anything other than 5W-30 in the car, so I'm assuming either Terry Dyson or someone at BioSyn recommended it.

 

The short answer is that I don't know. I only have 2 data points.

I'm not an oil or engine expert, but I did stay at a Holiday Inn Express last night (that line is starting to get old) so I will tell you my thought process. I don't believe in babying an engine during break in. I don't race it, but I put it through the entire RPM range. I changed our oil out at around 2K to flush out all the wear metals and factory assembly lubes and other "gunk" from break in. Looking at my UOA and others, it seems that MINI/BMW Castrol is a good oil. After 8K miles it has maintained 5W30 viscosity and seems to protecting the engine from wear. However the acid neutralizing ability is kaput (TAN=TBN) so time for a change. It's too bad, if there was more base built into the oil or if there was a way to add more, it would last longer. I would recommend not running MINI/BMW Castrol (or Pennzoil Platinum for that matter) for longer than about 8K miles.

One should also take into account how the MINI is going to be used. Some people don't keep a car for much more than 4 years or 50K miles (length of the MINI warranty). There isn't much point in spending a lot of $ to maintain the car for the next owner. We will probably keep our MINI for at least 7 years and 200K miles so I want to avoid having to rebuild the engine in the future.

 

I am running BioSyn in all our cars based on Terry Dyson's recommendations and UOA results: 2007 MCS (0W20), 2007 Toyota Sienna Ltd AWD (0W20), and 2002 Porsche 911 C4 (5W40 HD, gear oil and tranny oil). I use 0W20 for the street only cars (the wife will not let me take the MINI out on the track ) so I'm not worried about high temp high stress use. I'm trying to get as much MPG as I can so I am using the thinnest oil and watching it closely. The 911 is different, I beat the crap out of that engine on the track and autoX so I wanted a really robust high performing oil.

 

Thanks for the advice!

So you're suggesting something like (for a committed owner anway):

2k- 1st oil change
10k- 2nd oil change
18k- that's about the first waranty oil change, right?
24k- oil change

So on an so forth... does that pattern out to 1 oil change between waranty oil changes?

 

Makes sense - I autocross my MINI, so I'll probably stick with the BioSyn 5W-30, but I'm looking forward to hearing how the 0W-20 does in the MINI.

 

I like to change mine out every 5k. It's a number that I can easily remember based off of my odometer. This may seem a bit excessive, however, the fuel dilution and flash point numbers are reason enough to warrant it. IMO.

 

I think this is overkill. I have followed the MINI factory oil change intervals in all my 4 MINIs and I have yet to have an issue. Over 100K miles combined under my belt.

The gentleman that was featured in WRR interview (MTTS Chicago) that has a 2002 MC 5-speed with 281K original miles on the odo. He said that he has changed oil and filter every 10K-15K miles or when the computer tells him to. He is got one of the highest mileage New BMW MINIs in the world right now.

Maybe the technology works after all. I see no reason to to change synthetic oil every 5K miles, unless, the car sees heavy track usage or it is driven in very dusty environments.

 

I agree with ClubmanS. Dateline did a story back in the late 90's about how often should people change their oil back when it was 3K every change. The put 60 NYC taxes on the road half being changed every 3K and the other half being changed at 7,500. There was no difference after 50K miles with the torture that NYC cabs go through. They said there was no reason to change it before 7,500K that was with any SAE certified oil.

Now with synthetics it should be able to go 15K like the older oil could go longer. I have a CLK 430 that has only been changed every 10K like the computer says and it has 9 yrs and 120K with no problems or smoking and I ride it hard all the time.

 

I think there's a happy medium between changing it every 5,000 miles and waiting for the OBC to tell you it's due. If I had followed the OBC recommendations for my MINI, I would have gone 21,000 miles between oil changes, but when I had the oil tested at 9k, it was pretty much already at end-of-life. I'd be scared to know what it would have looked like after *another* 12,000 miles.

Also, engines and oil have changed appreciably in the last few decades:

With each new API oil specification, maximum allowable levels of wear additives like zinc phosphate have been lowered, because those additives don't play well with catalytic converters (which the EPA requires that automakers warranty for at least eight years/80,000 miles). There's also been a trend toward using lower-viscosity "energy conserving" oils in an effort to get the manufacturers' EPA fuel economy ratings up.

In the quest for more power from smaller engines, cylinder pressures are higher than they've ever been, and the move to direct-injection fuel systems is hard on oil as well. In the old days, carburetors essentially dumped the fuel into the intake tract, and it was only the engine vacuum that pulled the fuel into the engine. Then fuel injection came along and injected the fuel at 60-100 psi. Now with direct injection, the fuel is shot directly into the cylinders at up to 30,000 psi. Since the piston rings rely partly on combustion pressure for sealing, they're not forming a perfect seal with the cylinder walls during the intake stroke, and some of this high-pressure fuel leaks past the rings into the oil.

In short, while some engines are harder on oil than others, there are significant politcal/economic pressures on automakers to extend oil drain intervals as long as they possibly can without causing immediately-obvious short-term problems.

 

Do you have a link/reference for the Dateline report? It sounds like you may be thinking about the Consumer Reports "Taxicab Test" from 1996, which is a little different from what you described.

In short, the CR test was 75 taxis and 20 different oils, and they *all* got 6,000 mile change intervals (there was no 3,000-mile 'control group'). After 60,000 miles, CR tore down all of the engines to measure wear, sludge and varnish. They found that wear was minimal and didn't really vary from one brand/weight of oil to the next.

So the gist of the CR report was that you should be able to go 60,000 miles with no significant problems using 6,000-mile intervals, but that report in and of itself doesn't justify the intervals that MINI and other manufacturers are recommending now (10k, 15k, or even 20+k).

 

There are three things to consider here:

1) How much did you Mini cost? $$$$$

2) How much does oil and a filter cost? $$

3) Are there any negative effects of changing the oil too often? NO.


Changing your oil at frequent and regular intervals always has been and will continue to be the cheapest insurance you can buy for your car to ensure long engine life. If you don't see the irony in how all of a sudden when manufacturers are starting to pay for scheduled maintenance the intervals grew longer...

OW20 seems very low for a summer oil in a turbocharged car. Every other european and japanese turbo 4 cylinder on the market recommends 5w30, 5w40, or 0w40 (which I run).

 

Overkill for a DI motor though? I don't think so. It's not really a fair comparison to the first gen cars. More fuel dilution = a lower flash point for the oil. Unless I have some misunderstanding, this is more of a problem with DI motors verses common rail fuel injection.

 

Smackboy thanks for sharing your results. I like reading this stuff. I went 15k for my first change (dealer) but I'll tighten up from now on. I keep cars 100k/7 years usually, but I'll probably get the JCW bug before that with this car (lol).

 

I have to say that I'm a little concerned now about buying a used MINI if some people are only changing the oil every 12,000 miles! I guess I haven't changed with the times and feel guilty if I go longer than 3000-4000 miles.

The only way to get the iron, copper, and aluminum out of there is to change the oil, no?

 

+1

 

The people who follow the recommended interval (determined by the OBC) are changing the oil no sooner than 15,000 miles* and typically closer to 20,000 miles. I would also be concerned about buying a used MINI unless I knew that they had changed it more often.

*There may be rare situations where the OBC calls for an oil change earlier than 15,000 miles, but I don't recall reading any accounts of that here. Quite a few people have posted that their OBC is telling them 19,000 miles. That is about where mine indicating.

 

My civic 06 called for it every 8K and never had a issue, I am not worried about resale it will be there as long as you do it as recommended(gets off soap box)

 

PS my benz also was close to 15K and no issues on any of them oh and nots let forget my stable of crossfires.....

 

Are either of these motors direct injection? I don't doubt that you can go 10-15k on a non DI motor. Instead of comparing apples to oranges lets consider the data as it relates to the motor design in question. So how are other cars with direct injection turbo doing with long drain intervals? Is there a point where the fuel dilution / flash point numbers would indicate it's time for an oil change. At what point does it become detrimental to the engine to leave the oil in? I'm simply taking a pro active approach based on my limited understanding. I would like more hard data on the issue.

 

And that is what the majority of the UOA's posted on this forum seem to point toward. hmmm....

 

Could someone post a simple explanation of why these values are important? And why they suggest that you should change the oil?

I also assume BMW has access to similar data, so why doesn't it worry them?

 

That's it. I am doubling my interval to 10K miles.

 

That's right. Plus IIRC it was pointed out at the time that taxi cabs are not driven like typical passenger cars. Cold starts accounts for a significant proportion of engine wear. Taxis are started once in the morning and turned off at night. They are mostly driven in stop and go traffic, and a lot of idling, not exactly a high temp high stress environment for a modern liquid cooled engine.