BMW just did an oil change of my 745 and told me come back to get it changed in 15,000 miles Is synthetic oil that good?

Research seems to show that Shadow and I have used for a few years now and it certainly looks cleaner coming back out. but how much better, ?

I have put some high miles on some Caprice cabs, a Regency , and a LeSabre using Dino Juice. I like it best because it has a longer life before molecular breakdown and I tend to stretch the 3000 mile or so limit of normal oil.

I would still change it at 3K

I still go with the idea that the duration of your oil depends on the condition of the engine you put it in. No matter what type of oil you put in a dirty, crudded up engine, it ain't gonna last as long as oil put into a nice clean engine. So, a happy median between manufacturer recommendation and knowledge of your vehicle should be used.

I'm 99% sure (without looking it up) my owners manual says 7,500 miles. I know I have a rebuilt engine with about 30,000 miles on it. So, even with full synthetic, I'll do the changes at around 3000 to 5000 miles.

Isn't it only specific kinds of synthetics that can last 15,000 miles?

I switched to Mobil 1 in April when I got the car. I never read what the oil-life was but I still change it every 3000 miles. Since I do mostly highway driving I may end up missing it by 500 miles or so.

I changed it a month ago after less than 4000 miles and the oil was very noticeably darker, though not black. I was surprised, but not, since it'* an older engine that I have to assume was not taken care of as well as I would care for it (the SC oil was BLACK when I changed it). I'll stick to 3000-4000max.

bonnie94ssei- yes only one type of oil i know can go 15K. Amsoil i think its called..

I use synthedic oil in my bonne. i dont change it every 3K i do it 4K and i usse a REALYT good filter and a bigger one. i use the Wix 53051 from a 5.7L

I agree with MOS. Depends on the cleanliness of your motor. Looks like your BMW is newer so I'd think it would be fairly clean still. I'd be a little un easy with 15K though. Maybe 7K or so. Also depends on your environment, dusty or smoggy, and what type of driving. Lots of HWY cruising is way easier on the motor than stop-and-go driving.

Mobil has 7500 and 15000 mile oil besides their regular full synth. I was thinking those are conventional or a synth blend though, but I could be wrong.