My owner's manual states 5w30 for cold weather and 15w40 for hot ...

i'm thinking of 0w40 year round.. is that a decent idea ?

That would be fine.

That's what I plan on doing on my next oil change. I have read of one person on here who experiences an oil pressure warning light at startup sometimes because the oil is so thin but he has an older E36 like me. I'll just wait and see what happens with mine.

I don't think you will significantly reduce the life of your engine by doing this. I do wonder why you'd want to risk it. You won't experience any seat of the pants power increase due to reduced pumping losses. 0W oil is not "racing" oil, it's the same oil as the rest, but cut with more mineral spirits...which means less (per unit volume) of the additives that are meant to do the protecting.

Several years ago I peeked into a Valvoline truck at a CART race and they had boxes of oil that were marked with numbers like 80W-100. For sure those engines have more heat and load to deal with than our street cars, still I think if there was a real power trade off to be made with thin oil those guys would have worked it out.

If you're concerned about your engine getting all the oil it needs you would do better to buy a good aftermarket high-flow filter.

It's what I run.
I did a bit of research. And like yourself, the 0W40 is the perfect fit.
5W30 is the "Energy Saving" formula but isn't good for anything over 70 degrees F. 15W50 isn't recommended by BMW (but the 0W40 is). I just think that the better the oil flows when cold (i.e at start-up), the better off it is. More prtotection when you need it.
Cut with Mineral Spirits? That'd burn off pretty fast. No worries about that one.
I live in a moderate cliamate and it really doesnt get that cold for that long, so 0W40 is perfet year-round (for me).

0W oil is not "racing" oil, it's the same oil as the rest, but cut with more mineral spirits...which means less (per unit volume) of the additives that are meant to do the protecting.

Wow. Uh.... where you get your information from?

head on over to the forums at www.bobistheoilguy.com (http://theoildrop.server101.com/cgi/ultimatebb.cgi) and do some reading.... because what you "know" is frightening me.

I get my info from the companies that make the oil. I race motorcycles as a hobby and have spoken to a lot of oil people in the past decade. I don't think they'd all tell the same lie.

Obviously, synthetic oils won't be cut with mineral spirits/oil, they're cut with the synthetic base. Regardless, the lighter oils offer less protection by virtue of their base/additive ratio.

The author above brings up another trade off with the light oil. It will certainly flow through the engine more readily at start up in cold temperatures, but it will also leave a thinner film on the engine's internals. So you start it up and get oil where it needs to go a little quicker but there is less oil in the places you want it to be before you touch the key. Which is worse?

Bottom line: The people who engineer these machines are probably more aware of what the machines need to stay running than we are. If you're going to experiment you're taking a risk.

Excellent post, that should sum up this entire thread:

Bottom line: The people who engineer these machines are probably more aware of what the machines need to stay running than we are. If you're going to experiment you're taking a risk.

Excellent post, that should sum up this entire thread:

Agreed!

And I must've missed the part that said 0W40 is a light oil. Guess I should pay more attention...

Bottom line: The people who engineer these machines are probably more aware of what the machines need to stay running than we are. If you're going to experiment you're taking a risk.

True, but at the same time, the e36 was designed with 1980-90's technology. I never saw 0W40 on the shelves before 2001.

Agreed!

And I must've missed the part that said 0W40 is a light oil. Guess I should pay more attention...

0W40 is heavier than 5w30... that w doesn't stand for weight... it stands for winter... the 0 and 5 represent cold weather pumpability... If you're not playnig down around down near the lower limits (below freezing, below zero) then there's no difference in the oils. 0w40 is thicker than 5-30 at room temp and engine operating temp

But it's always a tradeoff as to who to listen to, the guy who made the oil, or the guy that made the car... Here's a hint though: the guy who made the car wants it to appear cheap to operate, and doesn't really care if it lasts past 100k miles, the guy who made the oil would like you to buy his oil often and forever... you decide.

benz, bimmer etc want that motor to last 200k miles or they'll lose some of their prestige. it's not the used car owner they are worried about, it's the new car owner and his/her peace of mind knowing that their motor can/will last so long.

case in point - my E30 is 20 years old and has 230,000 miles on it and cranks right up without a cough of sputter.

-Ron

...back to the question.
The only issue I have with the 0W40 formula is that it's not as available as the 0w30 or 5w30 stuff (if that's your benchmark). The last time I went to get some, it wasn't on anyone's shelf and I was about to order a case. Then finally it started showing up again. I even went to a quickie change joint and asked the techs if they had any on-hand. They gave me one of those looks--> :confused <--

Oil is like politics and religion. A very passionate subject with lots of contradicting opinions and not easy to debate without getting irritated. The real experts are few, yet everyone's right (including myself, of course).

So long as it's changed when it needs it and is run at the right levels, you should be okay. Most oil-related problems are due to neglect anyway.

...back to the question.
The only issue I have with the 0W40 formula is that it's not as available as the 0w30 or 5w30 stuff (if that's your benchmark). The last time I went to get some, it wasn't on anyone's shelf and I was about to order a case. Then finally it started showing up again. I even went to a quickie change joint and asked the techs if they had any on-hand. They gave me one of those looks--> :confused <--

Oil is like politics and religion. A very passionate subject with lots of contradicting opinions and not easy to debate without getting irritated. The real experts are few, yet everyone's right (including myself, of course).

So long as it's changed when it needs it and is run at the right levels, you should be okay. Most oil-related problems are due to neglect anyway.

Heh, it's definitely a market thing... 0w40 supersyn is everywhere up here, but I've never even SEEN 0w30 supersyn..

probably depends on where you live - 0w40 mobile1 (not my first choice) is readily available at walmarts in PA and NJ.

0w30 seems to have been phased out with 0w40 around my areas as well. I used to run 0w30 in the E36 in the winter but went back to 5w30 since I'm not on the idea of going to 0w40 'European Car Formula'.

anybody notice the new weight 0w20? Fords and Hondas apparantly use it.

-Ron

I used to get the 5W30 BMW synthetic. It was fine. And with the BMWCCA disount, it's the same price as anything I can get off the shelf.
Then I looked in my manual and checked around a bit. In the warmer climates, my manual recommends 5w40, so I just went with th 0w40 stuff.
I was REALLY checking to see if 15W50 would work, since that's what I run in the bike and I'd just assume have one or two weights of oil than three (the Tahoe is still running 5w30).

The 0w30 is as readily availale here as the most common 5w30. Yes, I have been noticing the 0w20 stuff. What's next? Sewing machine oil?

So who'd y'all vote for? -kidding-

I vote for WD40. :D

as it is in my E36, I use Castrol Syntec 5w30. I used to use Mobile 1 5w30 but it burned allot for what ever reason. Castrol doesn't burn any where near as much. :dunno

the E30 gets Valvoline High Mileage 5w30 (hype? who knows).

I vote for WD40. :D

as it is in my E36, I use Castrol Syntec 5w30. I used to use Mobile 1 5w30 but it burned allot for what ever reason. Castrol doesn't burn any where near as much. :dunno

the E30 gets Valvoline High Mileage 5w30 (hype? who knows).

In my previous car I used to burn M1 5w30 a lot too... that was my primary reason for switching to M1 0w40.... it deoesn't burn off...

Yeah, the new 0w20 and 5w20 oils are newest gas mileage rage... I bought a Mountaineer with the venerable 302 V8... which they suddenly say 5w20 is the ideal oil for. :rolleyes I use M1 5w30 in that, as M1's 30's are really thin for 30's...

bought a Mountaineer with the venerable 302 V8... which they suddenly say 5w20 is the ideal oil for.

So, should I switch to 5w20 from 20w50 in my 87 Mustang 302 V8? :rolleyes

Ask a dealer and I bet they'd say yes. :(

So, should I switch to 5w20 from 20w50 in my 87 Mustang 302 V8? :rolleyes
use gear oil - 80/90 works best. :D

I used to use Mobile 1 5w30 but it burned allot for what ever reason.
.


Crazy, mobil1 10w30 burns pretty quick in my 97m3. I check my oil level twice a week, and always need to add a little. :(