The question of which oil to use in a motorcycle has been discussed and cussed for as
long as I can remember and still doesn’t have a definitive answer. Deciding on which
type of oil to use is like picking out your clothes, what beer to drink, and the list goes
on. You buy what you like.
As you may already know, oil choice is highly personal and riders can be fierce in the
defense of their favorite formulation. Recent comments on our website were made in
context of people blindly relying on the Internet without knowing where the information
is coming from or who is providing it more than an indictment of a particular oil, but it
did elicit some reader questions. We use and recommend motorcycle-specific oil for
two reasons. First, we are making recommendations for our customers and readers
and they don’t all ride the same motorcycle, nor in the same conditions. Case in point,
the owner’s manual for the very popular Yamaha WR250R specifically notes to NOT
use diesel grade oils. Additionally, we don’t have time to run every formulation or brand
of oil on our bikes for evaluation. Second, we have developed a network of experts
from all aspects of motorcycling and we’ve been lucky enough to learn from all of them.
This includes experts in the oil industry, race engine builders, aftermarket parts
developers, etc. The advice has always been the same – use motorcycle-sprcific oil.
We’ve never claimed to be experts in the field of rating oils, but we do claim to be
informed by experts.
A Shell Oil rep was contacted about Rotella use in motorcycles. Bottom line, they don’t
market it for motorcycles but if an engine doesn’t specify a gasoline spec higher than
SM and viscosity of Rotella is the same as OEM, the rep saw no problem. Shell did say
that it is not a motorcycle-specific oil and that their motorcycle-specific oils (not
generally found in the U.S.) have additive packages that differ from regular Rotella.
Shell said the JASO ratings itself is no guarantee that the oil is optimally formulated for
a motorcycle, only that it should be compatible with a wet clutch. Rotella does have
more additives than automotive oil so that helps.
Maxima Oil was contacted and they were much less flattering about Rotella’s abilities
as a motorcycle oil. As soon as we have more Maxima info we’ll include that in a future
article.
Bottom line, if you like Rotella and it meets the engine specs, use it. For our purposes,
we’ll continue to recommend motorcycle-specific oils for the same reasons the Shell
rep pointed out – additive packages are specifically designed for motorcycle engines.
Also remember that most motorcycles have an integrated transmission that uses the
engine oil for lubrication. Transmissions create very high pressures called shearing
forces and that’s why there are more and better additives in motorcycle-specific oils.
If the oil you use now is working well for you, that’s great. Go with the oil you feel
comfortable with; that way you’ll never second-guess yourself and you can spend your
time enjoying your motorcycle. We’re only passing on information we’ve collected from
expert sources.
A few oil facts from the experts:
Car oils are mandated by the EPA to contain zinc and phosphates. Car oil contains a
500 parts per million rating.
Car oil is also mandated to have OCP Polymers. Car oil uses Group 2 base stock
which is the lowest rating.
Motorcycle oils are also mandated by the EPA to contain zinc and phosphates.
Motorcycle oil contains a 2000 parts per million rating (4 times higher than car oil).
Motorcycle oil is mandated to have OCP Polymers. Motorcycle oil uses Group 5 base
stock which is the highest rating.
BIG SINGLE GEARING
This is another highly contested area in motorcycling, but again, we’ve consulted
experts in this field before using or recommending which combination to use on a big
single like the KLR650 and DR650. The experts convinced us long ago to never gear a
big single higher (larger front sprocket, smaller rear or both).
