Oil Comparo: OE BMW Castrol 5w-30 vs Mobil1 0w-40

[santov]

Well I just did my second oil change on my Z4. I was excited to bring the mileage as close as possible on my Mobil1 to make sure I had an apples-to-apples comparo. I know the OE Castrol is a good oil, but I'm loyal to the Mobil brand, it's a little cheaper, and it's easier to find locally. (I stocked 7 cases when a friend sold his garage stock).

I'm linking to my write up on my second favorite website. Most of the comments are valuable, but there are some dick trolls on the site.

I hope this shows you that both are good oils. The Mobil1 seemed to stay within weight spec for longer and have a slightly higher tolerance to heat. It had less moly, so it won't last as long, but I'm planning on staying around 5k miles between oil changes. I do think that if going with the factory oil change schedule the oil filter will saturate well before 15k. I'm ot sure how long it will last, but I'm not willing to find out.

As a side note my gas mileage has absolutely rocked.

http://www.bobistheoilguy.com/forums...68#Post2257268

In the future I'll let the dealer do my in-warranty oil changes (I'll only get one more), then stick with Mobil1.

[NSummers]

Good to know.. I'm 0w40 guy also. Where are you sourcing your m1 ? Local walmart sometimes has it for 6.75/bottle. Autozone wants like 7.5-8, any internet places for cheaper ?

I usually stock 2 cases (6 bottle each) a year, as I drive less than 5k a year. I'm ready to do my oil change next weekend.. seems like rain this weekend.

[NSummers]

BTW Did you get a magnetic drain plug ?

[wasupdu]

I just stocked up on Mobil 1 as both of my vehicles call for 0W-40 and the wife's truck takes some goofy Mobil 1 Fuel Economy weight that I can't seem to remember at the moment. 0W-40 Mobil1 is relatively easy to find, but the Mobil 1 Advanced Fuel Economy stuff can be tough to find around here.

Anyways, after rebates I ended up paying $4/quart + tax.

I picked up 8 cases...LOL

[santov]

Originally Posted by rsutoratosu

BTW Did you get a magnetic drain plug ?

No. I'm paranoid that the dealer will see something aftermarket and give me crap when the inspection comes. I am a believer in magnetic drain plugs tho. I'll get one when my service period expires.

Originally Posted by wasupdu

Anyways, after rebates I ended up paying $4/quart + tax. I picked up 8 cases...LOL

That's a good price for Euro 0w-40! A buddy of mine sold me his stash when he changed to a diesel. I bought 8 cases from him for $25= $4.17 a quart. At this rate that's a 3 year supply for me.

My wife's Infiniti V6 calls for 5-30 and Walmart sells a 5qt jug for $13. It's not full synthetic, but that engine has a short OCI anyways. I change it about every 3500.

[vachss]

Best deal for me on Mobil 1 0w-40 has been OSH. They periodically have $10 off $30 or $20 off $50 coupons. Combine that with Mobil's $12 off 5 qts rebates and you get down in the $3/qt range. God I'm such a cheapskate.