I've been poking around the 'net a bit and speaking to some different oil company techs about the SL rated oils, and the soon to be SM rated ones.
The SL's which we currently use are supposed to have better deposit control at higher temperatures. No one--and I do mean no one--can say just how much higher the temperatures can get with SL (than with SJ) and still provide "good" (whatever "good" is considered to be) deposit control.
But that's not what I wanted to talk about...
Anyway, the 'round the corner SM oils are being formulated to take even more of the zinc and phosphorous out. (This according to the Shell/Pennzoil tech I spoke to this morning). Other stuff will replace the ZDDP for anti-wear duties. Probably more moly...
Anyway, I have done some checking into the STP product. It's often maligned, but in most cases unjustly--I would think. The formula is tested extensively in all oils (syn included) and is compatible with the oil for any gasoline powered engine--old or new. The do not recommend it for diesels. Not sure why that is...
It would seem that the majority of horror stories regarding STP are from folks who over-used the product. Some have been known to just "add a bottle" of STP when the oil level drops by half a quart. Pretty soon, STP is all you've got. And the viscosity of the blue bottle STP product is 500 cst at 100C. The 4 cylinder forumula (red bottle) is a 200 cst version.
I was told that one 15 ounce bottle of STP into 4 to 5 quarts of 20W50 motor oil would change the viscosity to an approximate 25W70. The guy I spoke to at STP said the engineers had provided that info, and he didn't know why the winter weight came up only 5 points while the hot oil weight went up 20 notches.
Anyway, that's certainly on the thick side. Probably too thick for many engines. I'm thinking about 2 ounces per quart of oil would make around 25W "heavy" 50 or something such. I'm not as concerned about raising the viscosity as I am replenishing the ZDDP which is systematically being removed from our oils (all in the name of environmentalist-wacko-ism for the most part).
It might also be interesting to see how much the 4 cylinder version of the STP (the 200cst) stuff would raise viscosity. The STP tech guy didn't have that info.
I'm currently not finding a lot (if anything) wrong with boosting an oil's shear stability (which the increased viscosity should do) and at the same time putting back some of the barrier additives that have been proven to work for years.
Upset the oil chemistry?
Would this necessarily always be true?
The addition of STP to whatever oil you're using does not void any manufacturer's warranties. That begs the question "How bad could it actually be?"
And to the oft asked question "Why don't the big oil companies, who spend literally millions on their product R&D, put such an additive into their oils?"
The answer may be, in this age of an EPA run amock, "they can't."
Dan
[ March 02, 2005, 01:44 PM: Message edited by: fuel tanker man ]
The SL's which we currently use are supposed to have better deposit control at higher temperatures. No one--and I do mean no one--can say just how much higher the temperatures can get with SL (than with SJ) and still provide "good" (whatever "good" is considered to be) deposit control.
But that's not what I wanted to talk about...
Anyway, the 'round the corner SM oils are being formulated to take even more of the zinc and phosphorous out. (This according to the Shell/Pennzoil tech I spoke to this morning). Other stuff will replace the ZDDP for anti-wear duties. Probably more moly...
Anyway, I have done some checking into the STP product. It's often maligned, but in most cases unjustly--I would think. The formula is tested extensively in all oils (syn included) and is compatible with the oil for any gasoline powered engine--old or new. The do not recommend it for diesels. Not sure why that is...
It would seem that the majority of horror stories regarding STP are from folks who over-used the product. Some have been known to just "add a bottle" of STP when the oil level drops by half a quart. Pretty soon, STP is all you've got. And the viscosity of the blue bottle STP product is 500 cst at 100C. The 4 cylinder forumula (red bottle) is a 200 cst version.
I was told that one 15 ounce bottle of STP into 4 to 5 quarts of 20W50 motor oil would change the viscosity to an approximate 25W70. The guy I spoke to at STP said the engineers had provided that info, and he didn't know why the winter weight came up only 5 points while the hot oil weight went up 20 notches.
Anyway, that's certainly on the thick side. Probably too thick for many engines. I'm thinking about 2 ounces per quart of oil would make around 25W "heavy" 50 or something such. I'm not as concerned about raising the viscosity as I am replenishing the ZDDP which is systematically being removed from our oils (all in the name of environmentalist-wacko-ism for the most part).
It might also be interesting to see how much the 4 cylinder version of the STP (the 200cst) stuff would raise viscosity. The STP tech guy didn't have that info.
I'm currently not finding a lot (if anything) wrong with boosting an oil's shear stability (which the increased viscosity should do) and at the same time putting back some of the barrier additives that have been proven to work for years.
Upset the oil chemistry?
Would this necessarily always be true?
The addition of STP to whatever oil you're using does not void any manufacturer's warranties. That begs the question "How bad could it actually be?"
And to the oft asked question "Why don't the big oil companies, who spend literally millions on their product R&D, put such an additive into their oils?"
The answer may be, in this age of an EPA run amock, "they can't."
Dan
[ March 02, 2005, 01:44 PM: Message edited by: fuel tanker man ]
