What oil do you use?

[nando]

They should just get rid of 20w50 if that was true.
or do some modern engines still require 20w50?

no engine requires 20w50.

it's pretty obvious most people have no idea what the two numbers mean. for example, a 0w50 does not protect any less than a 20w50 - it just pours a lot better when it's cold. you don't usually see oils with that big of a "spread" because, especially with mineral oils, they have to use a lot of additives to get it to pour at low temperatures, which results in less base stock (and less protection). a synthetic just naturally pours better at a lower temp without extra additives.

or, if they don't have a lot of additives and they have a large "spread", they're really expensive. see TWS 10w60 for example.

you basically want the lowest 1st number you can get, with a base stock that's not so watered down with additives that there's not much actual oil. a 20w50 is definitely not better than a 15w50 - but it's (slightly) cheaper, and you could use it if you lived in Saudi Arabia or something. :p

[griffincox]

The problem w this is that the filter is not good for 8000 miles

Source? A "good" filter can last 15k miles or more.

[griffincox]

mobil 1 0w-40 full syn. Anyone used these before? First time trying these out

Thought about running it in the winter. I run it in almost everything else (newer, lower miles). It's a great oil. But a little thin for an M20 in a warm climate.

[NeedaE30]

Mobil 1 15w-50 with half a quart of lucas oil stabilizer and either a MANN or a Mobil 1 oil filter depending on whats available and closest. stay FAR away from Fram/purolator and please avoid using store brand oil like auto zone brand or super tech shit from wal mart.. I swear its recycled oil...:roll:

[amcink]

Lubro Molly 10w-40 every 5K miles

[gtdragon980]

I use rotella 5w40 synthetic. Runs silky smooth with it. I used to do the 15w40 but I figured the synthetic 5w40 should be a tad bit better.

[Earendil]

read the owner's manual it tells you what oil to run based on the temp. and unless it's winter and below freezing. 20-50 is the best. and 5-30 is never to be used. there are many dyno runs to show that 20-50 non-synthetic is the best for your M20

How would a dyno run tell you anything about whether you car was suffering increased friction/wear from a less protective oil?

It does when these supra's run 700-1100HP DD/track and use the stuff with great benefits with wear, adequate oil pressure, and superb lubrication.

So yes.. to DD any 700HP car reliably would be the epitome of reliability.

But when talking about a good oil vs a bad oil for a DD, we're talking about whether the engine goes 150K, 300K or 500K miles, not something a person with a custom 1100 HP is worried about. They're probably happy if they make it to 100K without needing a rebuild.

[Earendil]

a 20w50 is definitely not better than a 15w50 - but it's (slightly) cheaper, and you could use it if you lived in Saudi Arabia or something. :p

I'll probably be switching to Mobile 1 15w-50 and not changing my oil after ever track day. next year. My Engine oil used to get nasty black in a short period of time, but after 3 track days and three oil changes it's coming out really clear. When I went oil shopping this last winter the M1 15w-50 was twice what the GTX 20w-50 was for whatever reason, so I never looked back. Now it looks like it's only 50% more, which is easier to call "slightly cheaper" :)

Of course, if you're DDing you car and changing the oil ever 6 months, it's a lot harder to not budget an extra $30 for oil to get some quality stuff.

[nando]

I use rotella 5w40 synthetic. Runs silky smooth with it. I used to do the 15w40 but I figured the synthetic 5w40 should be a tad bit better.

you are correct, but the next question is which has adequate levels of ZDDP for an M20? the 5w and 0w oils tend to have under 900ppm which isn't enough. the 5w40 will definitely be better on cold starts but will be no good if it wears grooves in your cam.

I'd really like to try M1 5w40 turbo diesel truck in my M20 - pretty sure it's SM rated as well. it makes our POS Subaru not sound like a total POS Subaru - but it's difficult to find and almost 30% more expensive. Last time walmart had some, I bought 4 jugs, as half the time they don't have any at all. with other oils I've tried the Subaru is really, really loud when cold - closest thing I can find is a shell 10w40 but it's too thick for cold starts.

[tinkerputzer]

When I went oil shopping this last winter the M1 15w-50 was twice what the GTX 20w-50 was for whatever reason.

Some walmarts have 5 qt jugs of M1 15w-50 for around $25.

[digger]

i've been thinking about using this

http://www.penriteoil.com.au/pis_pdfs/1510%20TENTHS%20PREMIUM%200%20JUNE%202013.pdf

[Earendil]

Oiy! Let me end all this right now with a link I pulled from a discussion the Pro3 guys were having.

Check out the article labeled "Motor Oils, ZDDP, and Vintage Engines"

http://www.intermarque.org/images/IMM1008.pdf

Among the links they have in there is one to the Mobile 1 product guide, who they say is one of the most forcomming companies with what they put in their oils.

http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf

Looks like I'll be switching to 15w-50 for sure now :)
The rest of you do as you will, but you might want to avoid the noted oil grades at the very least!

[ak-]

Rotella T 10-40 or whatever it might be.

[Cletonius]

Mobil 1 15w-50 with half a quart of lucas oil stabilizer and either a MANN or a Mobil 1 oil filter depending on whats available and closest. stay FAR away from Fram/purolator and please avoid using store brand oil like auto zone brand or super tech shit from wal mart.. I swear its recycled oil...:roll:

The Napa branded diesel oil is supposedly the same as rotella 15w40. At least that's what my buddy who works there told me. Can anyone verify?

[deeze30]

Thought about running it in the winter. I run it in almost everything else (newer, lower miles). It's a great oil. But a little thin for an M20 in a warm climate.

on the jug it said it's formulated for Euro cars but i guess they meant newer cars lol