Do "miracle" oil additives really work?

[gerharddvs]

[jessright]

I have allways been of the school that regualr oil changes is all that is required.  In the case of an older engine with alot of miles on it.  You can wash away deposits in an engine that have accumulated over time and the oil pump will not be able to create adequate pressure.  Consequently rendering the motor usless (well, good for a rebuild).  :lol:

That being said,  there is a guy in suburban Atlanta,  runs a high performance motorcycle shop.  Builds race bikes etc...  he swears by Marval Mystery Oil (a fuel additive!).  Says it lubricates the top-end,  valve seats and areas were engine oil does not travel.

J

[MarkB]

It depends on the specific product and the application but mostly the adage "If it seems to good to be true, it probably is" or "If it worked as well as they say, why aren't the oil manufacturers using it?" applies.

Of the two you mention, the claims are unsubstantiated:
Prolong: http://www.ftc.gov/opa/1999/09/prolong.htm
Duralube: http://www.ftc.gov/opa/1999/05/duralub2.htm

Marvel Mystery Oil is largely composed of solvent (as is WD-40, see http://householdproducts.nlm.nih.gov/cgi-bin/household/brands?tbl=brands&id=13005001 ) and as such has legitamate application where you want to remove deposits and apply light lubricatation. I've seen recommendations to add it to crankcase motor oil and run the engine for a bit to loosen deposits prior to a fresh oil change.  This idea may have some merit.

[Dragonfly]

I am an Rx-7 enthusiast , and anyone who is familuar with Rx-7 is familuar to some degree with  the rotary engine.
In a rotary oil is injected into the cumbustion chamber to lube the apex seals.
Sometimes this oil wont burn off properly and will leave heavy carbon deposits on the leading edge of the apex seal.
We swear by MMO (marvel mystery oil). It attackes and destroyes those oil carbon deposits and conditions the rubber seals in the motor.
I run small amounts fairley regurlary through all my non-rotary vehicles.
It seems to do a good job keeping the deposits down.

[GeeP]

I agree with jessright.  Regular oil and filter changes combined with good operating practice are key.  If you follow those basic rules you'll find your engines lasting a very long time.

I have a Chrysler 2.5L 4cyl I just overhauled @ 485,000 miles.  Top end was fine except for some mild cam spalling.  All main bearings were perfectly fine, not a scratch.  The cylinders however were shot - to be expected.  .040"  bore out and she's running again.  Change the oil and filter every 3,000 miles.  Just the cheapest Wal-Mart oil and filter I can find.  The oil meets NGLI spec. No need for anything more expensive.

As for MMO, I'm convinced that it's actually MIL-5606H aviation hydraulic fluid.

[Rema1000]

nope.  They don't.


heh.  Or, rather:  most failures occur because of improper care (just my opinion).  If you take reasonable care of your GS, then you're already in the top 30% or so of motorcycle owners.  If you take really good care of your bike (like: brake fluid and oil change each spring), then you're in the top 2% of owners, and using oil additives might move you to the top 1% at best.

So... maybe they make a difference.  But just caring for your bike will make a much bigger difference, regardless of what brand of oil you buy (yes, even $0.88 Wal-Mart oil).  Care is more important than chemistry.

[The Buddha]

Marvel mystery oil was mostly a light penetrant and some additives and a solvent ... whihc slowly evaporates in the temperature ... or so I thought from what someone posted on the savage mailing list few months ago ... So wd40 and additives sounds about right ...
Cool.
Srinath.

[scratch]

If you take really good care of your bike (like: brake fluid and oil change each spring), then you're in the top 2% of owners, and using oil additives might move you to the top 1% at best.

And if you change your fork oil every two years, you'll be in the top 0.5%(?).

Didn't we have a discussion that determined that WD40 breaks down petroleum products? So, if it's in MMO, why would we put it in our oil?

[callmelenny]

IMHO these miracle ingredients fit into two catergoies

1. things designed to remove stuff
2. additives that claim to add functionality to the system

#1 MMO and others like it are mostly solvents I think and may help remove deposits. But at worst, they are wasted money and are burned up out the tail pipe. I know some pilots that burn MMO as a gas additive and also add it to the crankcase right BEFORE an oil change. As a group, pilots seem to  be pretty careful about what goes into their engines.

#2 These often contain PTFE like compounds that claim to coat and protect parts. I'm am more dubious of these claims and also concenerned that added particles might cause harm. This would seem to be particularly true with motorcycles with "wet" clutches.

I'm not an engineer, just my $.02  :dunno: