My thought is that it is gradually consuming oil (at that mileage it is no
mystery) and that the drop during freeway use is a combination of burning
oil and of evaporating water that has gradually accumulated in the oil in
city driving - unless the oil was recently changed. Not really much you can
do about it except to make sure you use only API certified oil; some that
are not API certified (like Amsoil) have excess ZDDP, which may not be a big
problem with low oil consumption but will quickly poison your catalytic
converter if you burn much oil. Same applies to STP - unless they have
changed formulation recently it could kill your catalytic converter. For
more on that see http://www.lnengineering.com/oil.html

Mike

<techman41973@yahoo.com> wrote in message
news:52f6197c-6293-4831-b042-f9501eabc1cf@o4g2000pra.googlegroups.com...
>I have noticed that my Accord has been using oil on long freeway
> drives (400 miles +)
> I seem to be low 1/2-1quart after a long freeway drive.
> I may also be losing oil on normal driving (but its probably less).
> I don't see any leaks when the car is parked. Not sure if its being
> burned or whats happening to it.
> Has anyone else experienced this on their Honda engine?
> Do those oil treatments help? Which ones would you recommend
>
>
>