PittsDriver

BMW includes all scheduled maintenance for 4 years when you buy their car new. They ask you to bring it in when the car says it needs an oil change which for me has sometimes been well over 10,000 miles. It's supposed to adjust that interval according to how hard it senses that it's being driven. But even if I haven't gotten a service indicator from the car, I can bring it in once a year for the no-additional-cost oil change service. They call it a low mileage annual service and cover it. So it's interesting that they feel it's OK to run the miles up pretty high on oil but still pay for changing it annually either way.

It would also be interesting to know if the BMW calculus on this is that they only care about the engine lasting the length of the warranty or if they actually have some data that says high mileage on modern synthetic oil is no problem at all.

BadFish523

Not concerned about the oil breaking down with time even if the miles are low?

Mod (Ret.)

My wife drove a BMW for years. I found it interesting that BMW used to insist on oil changes every 3 to 5K, depending on the model (M series verses non M series). Then the "free maintenance" came about, that BMW picked up the bill on. And with that, BMW said their engines and oil could go 12K or a year. I finally got around to asking a service advisor about that. he stated it was because the newer synthetics they used were better, and rated at longer change intervals.

Mod (Ret.)

I'd say it depends on the climate in your area of driving, along with your driving habits (I.E. short drives where the oil and engine do not get up to operating temps long enough).

nrivera04

Did I read that somebody actually likes chaning oil?! I've turned many a wrench over the years and changing oil (or any fluids for that matter) is something I have always loathed. To the point now that I always pay someone else to do it haha.

Adam013085

No not really. It's not been an issue the past 4 years in my F150 using Motorcraft and now Mobile 1. I can't claim the same for my Jeep since I've only owned it a few months but it's not something I'm overly concerned about. I won't loose any sleep over it.

jshillin

iTrader: (1)

I change it every 5k or annually, whatever comes first... My F-150 sees right about 5k a year, same with the '14 Durango, but the WRX might see 3k a year if it's lucky.

hahanson

He should be. Obviously to what degree depends, and it's more of a concern with conventional oil rather than synthetic oil. The main cause for concern is oxidation -- a natural occurrence and the most common chemical reaction which causes oil degradation.

Why is conventional oil more prone to this reaction? A couple of reasons. First, because synthetic oils have less impurities. Some of these impurities, particularly compounds found in solvent refined mineral oils, are less stable than the paraffinic molecules that comprise the majority of molecules in PAO and highly-refined (hydrocracked) mineral oils.

The other reason is that Group III oils have fewer reactive hydrogen and carbon atoms. These atoms are more prone to direct reaction with oxygen. The whole point of Synthetic oil is controlling the chemical structure of the base oil molecules. By doing this synthetic base oil limits the number of reactive hydrogen and carbons atoms, improving its resistance to oxidation.

If you're looking for a more in depth explanation take a look at this article.

Chemical reactions other than oxidation will also take place with conventional oil, even sitting in its original container, such as leaving the unused part of a case of oil from you last oil change in cold temperatures (such as sitting in a garage over winter). Waxes form, making the fluid thicker and changing the viscosity. I'm going to be lazy but for more info check my posts in the oil stickie. There's a link there that will explain the science behind that.

Adam013085

@jshillin we are in the same boat .

Obviously I'm using synthetic since I'm doing annual changes.... I'll check back on this thread in 5 years and report the results

BadFish523

I only put about 7k on my truck a year but I change my oil at 3k or 3 months using Motocraft syn blend because its not just miles that break the oil down. Now that Ive decided to use full syn I plan on doing them every 5 months. After you go through or pay for a timing job and understand what can cause the problem you might re think the whole annual change thing. Or you might get lucky, or even just choose to ignore timing problems. The important thing to remember is it YOUR truck and you can do what you choose.