STech 15W-40 CI-4/SJ and RTS 5W-40 CJ-4/SM blen

[Pantdino]

For my 1995 BMW M3 with 157,000mi I bought 8 gallons of SuperTech 15w40 CI-4/SJ, thinking I had scored a great deal because the SJ has more ZDDP than the SM oils coming onto the shelves. But then I posted here and STech was described as being a "3000 mile oil."
I live in Los Angeles, where we seldom see less than 40F temps.

from other posts on this site,
The STech CI-4/SJ has:
TBN 9.02
Ca 3016
Mg 9
Ph 1179
Zn 1226
Bor 0
Moly0

the RTS has:
TBN 8.3
Ca 820
Mg 1298
P 1067
Zn 1294
Bor 61
Moly60

If I had to do it all over again I wouldn't have bought the STech, but now I have 8 gals of it.

If I mix these 50:50, would that be a good mix for this car?

Thank you

 

[Chris142]

The ST car oils would not be my 1st choice for extended drains. This is a HDEO and looks like a great oil. Same stuff thats in my peterbilt.

 

[jstutz]

personally i dont think i would mix them. The RTS is a low Ca high Bor and Mg formulation and the ST is a standard kinda high Ca blend. I dont know that it would hurt per say but i dont know that it would be better. Without arguing about which is better because i think the debate would go on a long time, but the ST HDEO is at worst case a very good oil and it will run fine in your BMW. If you are concerned about it, shorten your ocis a little and use it up, but i just use it up with normal OCIs.

 

[Familyguy]

Why not sell the ST oil to someone else at some small loss and just get a decent oil for your M3? Surely you can find someone here that has a more appropriate home for such a fill. Even if you gave it away to some needy BITOGer, we're only talking what...$80 worth of oil?

 

[Pantdino]

Originally Posted By: Familyguy
Why not sell the ST oil to someone else at some small loss and just get a decent oil for your M3? Surely you can find someone here that has a more appropriate home for such a fill. Even if you gave it away to some needy BITOGer, we're only talking what...$80 worth of oil?


How about if I just save the ST for my DeTomaso Pantera, with its 351 Cleveland? But 8 gal will last me about 6 years at once a year change because I drive it little.

I drive the BMW about 7K miles per year and change the oil about every 3500 miles. Once I used Mobil 1 and the UOA showed the oil (base excess) was about used up at 5000mi so I don't do extended OCIs.

 

[Familyguy]

That would be an ideal oil for a 351C.

 

[Rand]

I wouldnt mix.. they use very different additive chemistry.


That oil should be fine for 6month/ just use it.

 

[HTSS_TR]

Why don't you return those 8 gallons of SuperTech to Walmart, if you don't have receipt they will give you Walmart credit to buy something you need.

 

[m37charlie]

In a 95 M3 I'd run Mobil 1 0W40 or Redline 10W60.

Charlie

 

[Pantdino]

Originally Posted By: m37charlie
In a 95 M3 I'd run Mobil 1 0W40 or Redline 10W60.

Charlie


I have considered that, but the car takes 8 qts and @ $7 per qt for the M1 0W-40 I'm not sure its really that much better than RTS for my commuting uses.

I'm also not sure its formulated for an older engine.

 

[Pantdino]

So I filled with the RTS 5W-40 and was rewarded for doing the right thing
This morning my car thermometer read 39 deg F but there was ice on the rear window, so the engine was probably colder than that.
With the 15w40 Delo I had been using I would expect to hear a few seconds of lifter clatter upon startup at that temperature, but with the RTS there was only some minimal tappet chatter.
Guess 5W really does flow better than 15W!

 

[D-Roc]

AME is always an option. Some of these temps are just not cold.
It was -32C here this morning. The AME started coming through my BMK-11 about the same as it does at about a few degrees below 0C (unaided) I had my block heater plugged in and not my pan heater. So, the oil's going to be stone cold.
I once aimed a laser thermometer at the pan. The time I did that it was about 35 celsius most places on the engine, some colder than others. My pan was -22C.

 

[jstutz]

5w40 is awesome for winter when a HDEO is warrented. Its a little pricy but compared to the cost of the vehicle or gasoline, its not too bad. Good Luck

 

[Rand]

Originally Posted By: D-Roc
AME is always an option. Some of these temps are just not cold.
It was -32C here this morning. The AME started coming through my BMK-11 about the same as it does at about a few degrees below 0C (unaided) I had my block heater plugged in and not my pan heater. So, the oil's going to be stone cold.
I once aimed a laser thermometer at the pan. The time I did that it was about 35 celsius most places on the engine, some colder than others. My pan was -22C.


What is AME? and If it was -32C I'd move or get a pan heater

even something like
http://www.amazon.com/dp/B000BOABS6/ref=...ASIN=B000BOABS6

would be decent.

 

[m37charlie]

AME is Amsoil's synthetic 15W40. Because it is synthetic, it has a pour point of -42C. and its' viscosity @-20C. is only ~4400 cP, quite a ways from the limit for 15W40 at that temp of 6200cP (I think). But it is $7.90/qt and for that price Mobil 1 0W40 comes close to what BMW designed that engine to run.

FWIW I have that little Kat's heater. I'm going to try it on the diesel generator of my camper, which refuses to start below 25F. (with 15W40 in it).

Charlie

 

[Pantdino]

Originally Posted By: Familyguy
Why not sell the ST oil to someone else at some small loss and just get a decent oil for your M3? Surely you can find someone here that has a more appropriate home for such a fill. Even if you gave it away to some needy BITOGer, we're only talking what...$80 worth of oil?


If this is a good fill for a 351C it is probably also a good fill for my Fiat Abarth 850TC, which runs a 1050cc pushrod 4 cyl motor made in the 70's. So I will be able to use it all up before it expires. Otherwise that would have been a good idea.