The 5/30 is thicker at higher temperatures (summer time) while the 5/20 is
thinner at the same higher temperatures. At lower temperatures they are the
same. The oil is multigrade.

Just remember that the thicker the oil the more resistance it causes the
engine parts. But if it is too thin it's hard for it to stick to the parts
that need to be lubricated since it will flow like water, especially at
higher temperatures. 5/20 is a measurement of thickness/thiness (viscosity)
at both lower (5) and higher(20,30) temperatures.

Unless the engine is of very high performance then 5/20 and 5/30 might have
different results on the performance. For the average honda, 5/20 and 5/30
don't make too much difference. Of course it depends much on the weather as
well. If you're in Alaska you'd use different oil than if you are in
Florida.

--Viktor

"R Thompson" <rthomps9@columbus.rr.com> wrote in message
news:EH9_b.4023$Ze2.1583@fe1.columbus.rr.com...
> All Honda engines are using 5W20 now, even retroactively back to at least
> the 2000 MY.
>
> "Jazz Man" <tigereye@hotmail.com> wrote in message
> news:cH9_b.16065$XR.4105@newssvr29.news.prodigy.co m...
> > Hello;
> >
> > Just had my 2000 accord with 4cyl in for tis 30k mile service per owners
> > manual.
> >
> > Dealer may have used 5/20 instead of 5/30, can this cause any harm to
the
> > engine
> >
> >
> >
>
>