Re: oils, by Robin Chung
From [email protected] (Robin Chung)
Date 23 May 1997 01:42:15 -0700
Message-ID <[email protected]>;
Here we go again with the MC-oil claim...
This is mostly marketing BUNK!
Motorcycle Consumer News ran an article comparing bike oils and regular
synthetic oils. They disspelled all the rumors about MC-=specific oils,
both empirically and theoretically. In the end, even an MC-specific
synthetic oil won't run any better than a good full synthetic like Mobil1.
According to an article in MCN 2/94 (motorcycle consumer news), the
bike-specific oil versus regular "car" oil argument is bunk. The "car"
oils are actually as good as any semi-synthetic/dinosaur juice bike-oil.
For the same money, you are better off buying Mobil 1 Synthetic in your
bike for the same price as bike-specific semi-synthetic stuff. If you're
going to buy $9/quart MC-synthetic, you're paying double for the same
protection a regular synthetic could give you.
The synthetic (full) oils run fine in motorcycles as reported by the
Cal-State Physicist who ran the tests. In both real world and test bench
conditions, the Mobil1 synthetic outperformed all the bike-oils (Mobil1,
Castrol Syntec, Castrol GTX, Honda HP4[MC/syn], Spectro 4). In fact, the
Spectro4 was the poorest performing oil in the lot. The tests charted
"Relative Viscosity Retention" which is a measure of oil lubrication (VI)
breakdown over time/mileage. (VI retention is the index that MC-specific
oil marketers always try and trumpet over other non-MC oils.) The
conclusions were basically:
1. The Viscosity of synthetic based oils generally drops more
slowly than that of petroleum-based oils in the same application.
2. Comparing figures for Viscosity retention for the same oils
when used in an automobile would indicate that motorcycles are indeed
harder on oils than cars. (MC's share transmission and engine oil.)
3. The viscosity of petroleum based oils, whether car or
bike-specific, drop at the same rate when used in a motorcycle.
4. There is no evidence that motorcycle-specific oils outperform
their autmotive counterparts in viscsity retention when used in a
5. The greatest drop in Viscosity Retention occurred at 800 mi.
(Edited for brevity.)
The claims made for MC-specific oils destroying car catalytic converters
due to the zinc/phosphorous additives (Zinc dialkyldithiophosphate - ZDDP)
is also bunk. There is a federally mandated limit for the zinc additivies,
and it is the same for cars and bikes. BMW's run MC-oil as well in their
fuel-injected catalytic converted bikes. A corollary claim, that
MC-specific oils contain 'more' of ZDDP additives to protect against
extreme wear, is misleading. As stated above, ZDDP is limited by federal
regulations for all oils, and ZDDP is necessary only in extreme wear
conditions like metal-to-metal contact. This should only happen
in the event of complete lubrication failure.
When asked for responses from the MC-oil companies, MCN got no
conclusive scientific reply. All the MC-oil spokespersons stated the
usual marketspeak about (sheer stable polymers, extreme pressure
additives, etc.) but these are included in the non-bike oils as well.
Surely, MCN does not doubt that a bike-specific full-synthetic would not
perform better, but probably no better than full-synthetic Mobil 1.
And Mobil 1 costs about the same as bike-specific semi-synth. oil.
Folks, it's marketing. plain and simple.
(MCN, Feb 94:)
Relative Viscosity Retention
0 mi 800 mi 1500 mi 2500 mi type
---- ------ ------- ------- ----
Mobil1 100% 86.6% 83.0% 79.1% syn/auto
Castrol Syntec 100% 78.1% 74.5% Not tested syn/auto
Castrol GTX 100% 72.2% 68.0% " " pet/auto
Honda HP4 100% 69.2% 65.6% " " syn/MC
Spectro 4 100% 68.0% 63.9% " " pet/MC
The test bike was an 84 Honda V65 Sabre, oils sampled at 0, 800, 1500
miles (and the mobil1 tested at 2500 miles because its VI drop was
markedly less than the other oils.) Test performed over the course of
10,000 miles, over 1 year, 70% city, 30% freeway riding; in the test
order of Castrol, Spectro, Mobil and Honda.
Though the article admits that spectro's Golden Spectro synthetic oil
would probably have performed better than their non-synthetic spectro-4,
MCN doubts whether it would have been any better than the cheaper Mobil1
synthetic oil. The MC-specific-oil claims seem to be nothing more than
There have been some reports that motorcycle manufacturers were warning
against using API-SH certified oils. This appears to be the case only for
non-synthetic 'SH' oils which use molybdenum-based friction modifiers to
meet their 'energy conserving' requirements. An oil engineer I spoke with
verified that there had been some problems with non-synthetic 'API -SH'
oils in 'combined transmission engines' (i.e. motorcycles), but that this
was only in oils that used moly-based friction modifiers. As far as I am
aware of, Mobil1, for instance, does not use moly-based friction
modifiers. The newer 'SJ' certified oils are apparently fine.
I don't work for mobil1, nor any other oil company. Personally, I've used
mobil1 15w50 in all my bikes (SF Bay Area CA, where it's pretty temperate
year round, changing every 3,000 miles or so) over the last 6 years,
accumulating around 100,000 miles. Bikes ranging from an VF500 to a
CBR600F2. around 15,000 to 20,000 miles a year, mixed
commuting/sport-riding/track. None of my leakdown tests or
valve-adjustments have shown any adverse results of using non-MC oil.
It's your money...
Robin Chung 92 F2 pilot "Gillian"
Senior Performance Architect, MTI-V, XX Aspiring F1 Vehicle Dynamicist
AMA#699255 HRC#HM402849 FAX:(510) 642 4769
"do the words 'orenthal james simpson' mean anything to you?" 5/12/97