Switched to 5-30 Mobil 1

[arsevader]

when should 30 40 or 50 be used?

According to the BMW manual 10w-30 is only good up to 5 degrees celcius.

According to BMW, you can go 10,000 miles on the same oil/filter.

True but I'd would rather err on the side of caution.

James

[parkerbink]

Cut & Paste from Mobil 1 .com

What's the right oil for my car?


Our products in the viscosity right for your vehicle

We've taken what you told us about your vehicle and driving conditions, and using an auto industry database, have determined our products in the viscosity recommended by your vehicle manufacturer. These products are shown categorized by the level of protection they provide. To learn more about a product, click its name.



Current Vehicle:
Year: 1990
Make: BMW
Model: 325i
Engine Type: 6 cyl. 2.5 Liter






Ultimate Protection

Mobil 1 Extended Performance 10W-30
Mobil 1 Extended Performance 10W-30 fully synthetic motor oil is designed for today's longer service intervals. It provides guaranteed performance and protection for 15,000 miles or one year. Mobil 1 Extended Performance products contain 50 percent more SuperSyn, 37 percent more cleaning agents, and 36 percent more anti-wear additives than Mobil 1.

Mobil 1 10W-30
A fully synthetic motor oil, Mobil 1 10W-30 with SuperSyn Technology, exceeds warranty requirements for gasoline engines where an API certified oil is specified. Mobil 1 is recommended by leading car manufacturers as initial fill.

[trent]

Really you should use the most viscous oil you can get away with.

I completely agree with you on this!

[AdamF 88iS]

Fucking hell.

I'm sorry to get all you E30 lovers waffleswaffleswaffleswaffleswaffles hurt, but M20s are not some close tolerance high tech motor like you would like to think. They are mass produced loosly built slap together motors. You absolutly cannot run 5-30 in one unless you live in fucking Antartica. Did the fact that his motor is noisy as hell now not tip you guys off? 15-50, 20-50 or die; and change it every 3k on dino oil, or 5k for synthetic.

[wolf_walker]

I went from 20/50 to 10/40 as an experiment on my piston slaping-valetrain tapping 238K 325i, and it seems to like it. Piston slap seems better, MPG and rev-ability went up. It has not died in the last 2K miles of hard street driving. Quarter million miles, 26mpg average and "normal" power, what more can one ask. ~shrug~ Every non-BMW guy I talked to with motor experience said 20/50 was to heavy, which was my initial thought when the BMW guys all said 20/50. Who knows, you can't prove anything in this kinda deal. I might put in 20/50 again and compare engine noise level, but I swear it's quieter with the lighter oil. ~shrug~

And any motor that can rev repeatidly to 6500+ stock is not a slap together motor, sorry. Go drive a mid 80's domestic and try and do that, see how many times it makes it. Remember what BMW stands for, eh?
No there not all M cars, but come on.

[AdamF 88iS]

And any motor that can rev repeatidly to 6500+ stock is not a slap together motor, sorry. Go drive a mid 80's domestic and try and do that, see how many times it makes it. Remember what BMW stands for, eh?
No there not all M cars, but come on.

Ever built one? You can close your eyes and assemble an M20 man, come on. I didn't say they are poorly engineered, I just said they are setup to be mass produced quickly and with low cost. It's not some hand built masterpeice with tolerances measured to .00000001 and shit. They last a long time because they use relativly heavy duty internals and are not very stressed. If they did 8krpm then that would be reason to be impressed.

[nickmp0wer]

so what would be for for like 40-80 degrees? 10w-40? (m42 engine)

[wolf_walker]

And any motor that can rev repeatidly to 6500+ stock is not a slap together motor, sorry. Go drive a mid 80's domestic and try and do that, see how many times it makes it. Remember what BMW stands for, eh?
No there not all M cars, but come on.

Ever built one? You can close your eyes and assemble an M20 man, come on. I didn't say they are poorly engineered, I just said they are setup to be mass produced quickly and with low cost. It's not some hand built masterpeice with tolerances measured to .00000001 and shit. They last a long time because they use relativly heavy duty internals and are not very stressed. If they did 8krpm then that would be reason to be impressed.

Maybe my view is skewed by being a diesel driver the last decade, but I don't see many other motors of there vintage that can turn the speeds they do and last like they do. Maybe I'm easily impressed. I just don't believe they have the same kinda bearing tolerences as some old domestic motor. I guess I could look it up..

So how does one tell the oil is too thin? What are the signs? Or do you not know till you spin a bearing?

[AdamF 88iS]

so what would be for for like 40-80 degrees? 10w-40? (m42 engine)

In M42 you can get away with 10-40, the hydrolic lifters like a slightly thinner oil. 20-50 is ok during summer on that too.

[arsevader]

Really you should use the most viscous oil you can get away with.

I completely agree with you on this!

Glad someone does. ;)

Most people don't understand oil weights. That's not to come off as an expert but it's true. 10W-30 has become the "do-it-all" weight of oil for most cars but the fact remains that it's not appropriate for a lot of engines, M20s included.

The problem is also that it's reasonably hard to find synthetic oils in the middle of the range catagory (10W-40) so people are going with the lower weight oils.

Even the dealers are using 10w-30 for these cars even though the manual clearly shows it's not correct.

And people are also confusing viscosity with thickness.

James

[wolf_walker]

Even the dealers are using 10w-30 for these cars even though the manual clearly shows it's not correct.



James

And the manual says I can go how long between oil changes? :)


Seriously, how big a difference is 10 points of index, say between 10/30 and 10/40, or betwixt 10/40 and 20/50? My oil pressure comes up way faster with 10/40 than the 20/50 i had in there. That CAN'T be a bad thing, how much difference is there when things are hot? Numbers, film strength/thickness, bearing clearences, give me something more than gut feelings, I've already got those. (and they say 10/40)

It's not that I dislike 20/50, I've used it year round in things like a 78 Lincoln with 215K on it, 76 Chevy truck with 175K, even my VW diesel's ran Castrol GTX 20/50 for years back before they droped the diesel rating off it. But the BMW just does not seem to need it by my time engrained ways of feeling what's right for a motor. Tell my why that's wrong other than "it just is".

please, and thank you.

[arsevader]

And the manual says I can go how long between oil changes?

I don't believe the manual for the e30 actually says.

Seriously, how big a difference is 10 points of index, say between 10/30 and 10/40, or betwixt 10/40 and 20/50? My oil pressure comes up way faster with 10/40 than the 20/50 i had in there.

That's because you are comparing a 10 and a 20. A lower first number will always flow better when cold. That's why you should use a lower number in the winter. The problem comes when your range is too wide. Fresh oil will start to move it's index towards the lower number over time.

Tell my why that's wrong other than "it just is".

I don't think you are wrong. I think that 10W-40 is just fine for these cars. I think that 15W-50 or 20w-50 is a better choice but 10w-40 is perfectly alright. 10w-30 is just plain wrong because it just is. ;)

James

[kowalski]

you can go atleast 10,000 miles with synthetic oil but you have to change the filter every 3000

and if your talking about motors that are built for mass production then i must ask you what motor other then high end sports cars are not built for mass production? for that era these engines are pretty high tech, of course they're out dated now but for their time they were pretty damn good.

[bmwsmurf]

I used Mobil 10-30 on my previous E30, had it for 88k miles before selling it, seemed to work fine. At that time, there was research that showed that some 10-40 oils were not good for cars, because it was trying to do too much at both temperature extremes and ended up being very mediocre. In retrospect, the 10-30 might have been too heavy for the new york summers, but it worked.

Fast forward ten years, if anybody here follows the newer oils from Mobil 1, then you'll know that you need to buy the Mobil 1 0-40 weight European blend for all new BMWs, NOT 5-30, which is too thin. BMW's synethic oil, which is a 5-30 weight, is equivalent to Mobil 1's European 0-40 blend because Castrol makes it and it's a heavier 5-30 than Mobil 1's 5-30. BMW recommends this for year round use, and when I asked them, they said it is fine for E30s as well. So that's what I have in my car now. You can get either for your car.. Mobil 1 0-40 can be found at Pep Boys but they seem to never stock a lot of it... and BMW synethetic is actually slightly cheaper with a BMW CCA discount (4.xx versus 4.99) at the dealership.

For those trying to save money with regular oil, I can never tell which weights to use at the store, there are like 10 brands and too many weight variations. With regular oil, you have to change at 3k miles.. and with syethetics you can ride it up to 6-7 (I change it at 5) so it's not terribly more expensive, especially considering you also don't end up changing the filter as often.

For more info, google 'bob the oil guy'

[nickmp0wer]

i have quite a few quarts of bmw 5w-30 around my house so i guess i'll try that in my 318?