just got a 740iL 2001 and my father always used the recommended oil from BMW (Castrol). Mobil recommends mobil 1 0w-40. What do you guys think about this and does this oil last the 15000 miles b/w oil changes that BMW recommends. thanks

no reason to use anything thinner than the factory recommended 5w-30

factory says 0w 40 i use mobil 1 synthetic

i use 0w-40 in both my m3 and 740iL. Works great IMO. I wouldn't wait every 15k miles but ever 5-7k should be fine if you drive the car normally. Under hard driving I'd say every 3-5k miles.

i use 5w-30 elf because thats what they have at my shop and its quality oil, but i have been told mobile 1 is some of the best you can get...

I use the Mobil 1 on both mine, would not use anything else. However, I would not go 15k between changes, not even 10k. 3k - 5k maximum. ITs just not worth saving $50 on engines like these.

I have been debating over M1 and Castrol syntec.
- Read somewhere that M1 was bad for I6 engines and that it didnt meet euro specs set by BMW (unverified).
-I called up dealership and they said to use Castrol syntec. can any techs verify this?

is changing every 3k crazy? some people say to just go 3 months

i use mobil 1 in every one of my cars except my truck which gets an oil change every 400 miles (each trip) so not a chance is it getting $5 a quart oil...

I still change it every 3k or 6 months. Even if the oil 'could' stay clean and not break down over a longer period, just not worth it to me. Engines are expensive, oil changes are relatively cheap.

i feel like if i followed what the X5 listed, I would change the oil once a year or something ridiculous

I still change it every 3k or 6 months. Even if the oil 'could' stay clean and not break down over a longer period, just not worth it to me. Engines are expensive, oil changes are relatively cheap.

If you use full synthetic oils you don't need to change it that early. Yes, its cheaper to change the oil than replace an engine but that is just a waste of oil. Your engine will not break down by running it to 5-7k+. Plenty of oil analysis has been made showing full synthetic oil maintaining its elements beyond 5-7k miles regardless of driving style.

just got a 740iL 2001 and my father always used the recommended oil from BMW (Castrol). Mobil recommends mobil 1 0w-40. What do you guys think about this and does this oil last the 15000 miles b/w oil changes that BMW recommends. thanks

In Florida? 20W50. I think you can find Castrol synthetic 20W50 but I just use Mobil 1 Synthetic 15W50 year-round in Phoenix.

thanks guys, I have a link from Mobil 1 but i am not allowed to put it up b/c i am new to the forum. they have a recommendation of their oil for every bmw and their different engine types.

If you use full synthetic oils you don't need to change it that early. Yes, its cheaper to change the oil than replace an engine but that is just a waste of oil. Your engine will not break down by running it to 5-7k+. Plenty of oil analysis has been made showing full synthetic oil maintaining its elements beyond 5-7k miles regardless of driving style.

How's your filter hold up to extended intervals?

Castrol recommends 5w-30 syntec and mobil 1 recommends 0w-40 shouldn't they both recommend the same weight? Mobil 1 has a 5w-30 extended performance, maybe i should use that

I use the BMW oil from the dealership, 5W-30. I change it every 3k miles without fail. I would recommend changing it that often just to keep your engine in as best shape as possible.

yeah it depends where you live

i use mobil 1 0w40 on my E36, and bmw 5w30 on my E46.....thats the way i started so I am not changing now, even though i guess i could just use 0w40 on both

the bmw 5w30 from the dealer is actually quite cheap, like $5.xx a quart

As far as how long to run before changing, your best bet is to have an oil analysis run on a sample. It will tell you definitively how much life is left in the oil, wear metals, contaminants, etc. Changing full synthetic in a properly maintained non-turbo or -race engine more often than every 5k is completely unnecessary unless you are doing very severe driving (virtually all short trips, cold starts, towing, very dusty conditions). Use a top quality filter (OEM, Mahle, Mann).

How's your filter hold up to extended intervals?

A quality filter is more essential to change than the oil at those intervals, meaning you'd probably change the filter 1 time more than changing the oil. There are filters that can be used for an extended period of time but because of how essential the filter is to internal performance of the engine, I'd be more concerned to change it first before your high quality oil.

I've been hearing really g00d things bout RP :dunno

is changing every 3k crazy? some people say to just go 3 months

I do every 5000 miles. It's easier to keep track of oil changes (5,10,15,20).

Where do you buy oil localy, like walmart, pep boys...?

I use only Castrol Syntec 0w30 made in Germany. This appears the only one I could find that meets ACEA B3 and some other requirements. I've been changing it every 6,000 miles (much sooner than the what the lights suggested), and I would not go any longer than that. The oil that comes out is quite beat up -- dark, and lost quite a lot of its original viscosity.

I used to be a fan of Mobil 1 0w40 until analyses started to show that it is no longer fully synthetic, and in fact, contains way too much regular oil. In my own experience, used-up castrol was clearer than Mobil 1. That swayed me as well.

Castrol Syntec 0w30 is very rare here in Rhode Island. From 5 automotive stores I frequent, it is sold only in 1, and even then, with lapses.

-- Nick