[semi-hijack] While we are on the subject of motor oils and the like, and we have all these experts here: Do oil and gas additives, the kind you can by at the auto parts store, do any good at all? Is there something I can use that will clean my fuel injectors better than the stuff they put in my gasoline already, for example? Or are STP and the like all a bunch of hooey? [/semi-hijack]
To the best of my knowledge there is only one additive that has ever been recomonded by a car maker. * Techron really works.
From Help your money.com
Now if you use a top tier gasoline I doubt you would need any additives.
*Back in the 80’s the additives in gas was leaving hard carbon deposits on intake valves. Techron was the only way short of mechanical removal to get rid of it.
Ok, so what about the STP and Marvel Mystery Oil, etc., especially in regard to adding it to the oil?
I once watched an interview with an executive of a major motor oil producer. He said (my paraphrasing),
“We spend a lot of money doing R&D in an effort to make the best motor oil. If there was a new additive we could add to our oil that would give us an increase in market share, we would do it.”
So the question to ask is this: if those additives are so great, why aren’t the motor oil manufactures putting them in their oil?
I once watched an interview with an executive of a major motor oil producer. He said (my paraphrasing),
“We spend a lot of money doing R&D in an effort to make the best motor oil. If there was a new additive we could add to our oil that would give us an increase in market share, we would do it.”
So the question to ask is this: if those additives are so great, why aren’t the motor oil manufactures putting them in their oil?
The STP additive inserts additional ZDP and some other useful additives as well as thickening your oil.
The problem is that in the intervals that most people run, their additives DO NOT deplete prior to the oil being changed… and even if they did, changing the chemistry in your crankcase by screwing around with the ratio of additives in there isn’t the solution. If your oil’s additives fail during your typical oil change interval, you should shorten your interval or move to an oil with a higher level of additives/additive retention.
Incidentally, STP only has a few times the rate of additives per ounce of let’s say… Pennzoil or Castrol. As such, adding a little 16-oz container to my car’s 6-quart crankcase will only accomplish a small increase in parts per million of the additives in question, principally ZDP/ZDDP and Calcium.
Incidentally, here is an analysis of one of STP’s oil additives:
http://63.240.161.99:8080/bitog/voalibrary/stp-4-cyc-oil-treatment.jpg
Compare the rates of Zinc, Phosphorous and Calcium to the rates found in an late SL-era Motorcraft 5W30:
http://63.240.161.99:8080/bitog/voalibrary/motorcraft-5w30-syn-blend.jpg
and America’s best-selling diesel oil, Shell Rotella T 15W40:
http://63.240.161.99:8080/bitog/voalibrary/shell-rotella-15w40.jpg
Note that while the STP has more Zinc-Phosphorous than the Shell, the Shell actually has higher levels of Calcium than the STP… thus if you added the STP to your diesel pick-up with the Shell in, you’d actually be DECREASING your oil’s protection from acidity that is created by the Calcium.
In fact, even the relatively low-additive Motorcraft has more Calcium than the STP.
Sure you want to monkey around with this stuff?
I will note that even with the 5W30’s relatively low Zinc-Phosphorous levels, adding a small percentage of the STP may not really accomplish a notable level of increase in those additives.
Finally, as the Motorcraft is of a relatively advanced design, you should note that it likely has at least one or two noteworthy additives that don’t show up in the $20 analysis that I’ve shown you… you’d need to do the $9000 kind with a nice spectograph etc.
As far as thickening your oil, if you chose the right oil to begin with, your oil will be plenty thick enough. Thicker oil DOES sometimes make engines quieter, but if you WANT a 20W50 instead of a 5W30, then install a 20W50 at your next oil change.
If your oil thickens or thins very far out of its rated range, you have a mechanical problem and should get it fixed.
Marvel Mystery Oil is a harsh solvent. It is NOT a bad chemical, but it doesn’t belong in a running engine; if you were using it to wash down crudded-up parts during a rebuild I’d be fine with it. It is likely to beat the hell out of any lube you put it in.
Do you really want it freeing up a chunk of crap with the engine running?
If you really want a gentle cleaning solution for your crankcase, I know of one, but MMO really isn’t the best choice.
Pennzoil’s off-the-shelf 15W40, as seen at my local Sear Hardware, had notable Moly in it:
http://63.240.161.99:8080/bitog/voalibrary/pennzoil-15w40.jpg
Give me half an hour and I can dig up several other well-known consumer name brands with Moly in.
Be careful with your bike. Not hard to hurt 'em!
Not likely currently valid. They switch refineries, base stocks and additives around all the time. Most of the rumors like the one you heard are a couple of decades old.
Additives can be put into three categories: those that help, those that don’t help but do no harm, and those that do harm.
There are precious few in the first category. One is Techron fuel additive, as Rick mentioned above, which has been proven helpful in many cases. Not only is it recommended by car manufacturers, but my understanding is it’s even house-branded and sold by some. Another is Lubegard ATF supplement, which was recommended by Saab in a Technical Service Bulletin for a particular problem.
Lubegard makes many automotive fluid supplements. Their various transmission fluid additives have long been used by many (most?) high-quality transmission shops for certain applications. I have seen some positive results in the field with their power steering additive. I don’t know that all their additives definitely help, but from what I do know I have no fear that any do harm when used appropriately.
Probably most additives do little or no good and little or no harm. What they’re selling is not a fix in a can, but hope in a can. The main drawback is erosion of the contents of one’s wallet.
Some, however, can do harm, most especially oil additives with chlorine compounds. They make for impressive infomercial demonstrations, which are carefully constructed to give an impressive visual but don’t relate to real-world operation of the engine. The problem is that they can form corrosive compounds which actually make things worse.
Another thing to avoid is acetone as a fuel additive. I have seen a commentary by a refinery fuel development specialist (sorry, no link available, but this guy absolutely knows what he’s talking about) warning in no uncertain terms not to use it. A debunking of claims for it is seen here.
So with the handful of exceptions mentioned above, use of additives is generally not a good idea, and is sometimes an awful idea.
Penzoil’s additive package contract for their “standard” motor oils actually went out for bid this year. Next year’s oils will have a different formulation.