Yes, about $4 per qt. I have no justification for this expense other than
the _slight_ increases in the numbers as given below and that a local
rebuilder suggested strongly that I try it. This is the guy who keeps about
30 Jensen-Healeys on the road in the Altanta metro area.
Of course, quick math tells you that at 29 mpg, you'll burn 103.5 gallons
over a 3000 mile oil change interval, which works out to $124.20 at $1.20
per gallon. At 33 mpg, you'll spend $109.10, giving a $15.10 savings when
using synthetic vs regular oil. If you assume that Castrol GTX is $1.00 per
qt, and IF you don't burn or leak a lot of oil, you'll spend about 4 qts x
$4 = $16 on Valvoline synthetic and about $4 total on Castrol GTX, for a
loss of $12 over the 3000 mile oil change interval. Adding gas savings and
oil loss gives a total savings of $15.10 - $12 = $3.10 when using the
synthetic vs GTX. In reality, I probably burn and leak that savings over
3000 miles. But, at least I don't eat the whole cost differential between
synthetic and regular oil.
I have not completed my study of whether I'm having to add more or less
synthetic per 1000 miles than regular oil. I expect to have those figures
by the end of summer (the mileage tests were done over the course about
about 20 tanks of gas). So far, I'd say there is no gross difference. I
bring this up because many people have stated that they developed a lot of
oil leaks when they switched to synthetic oil. I have not found this to be
true for me on a gross scale, anyway.
I have fun monitoring this stuff. But please note that switching to
synthetic oil may give no benefit in YOUR car in terms of mileage. Even
without mileage savings, a $12 loss every 3000 miles doesn't seem like much
to me, given that I enjoy playing around with this stuff. OTOH, some folks
enjoy the challenge of running cars as cheaply as possible. I can
understand that different kind of fun, and that going synthetic may not be
fun for them. It's all a big spridgetly world.
TTFN,
Jeff
At 3:53 PM -0400 8/12/99, Ulix Goettsch wrote:
> Hi Jeff,
> is it expensive?
> Ulix
>
>
>
> On Thu, 12 Aug 1999, Jeff Boatright wrote:
>
> > I'm using Valvoline 20w50 full synthetic in my 1275 cc BMC A-series engine.
> > I find that it gives me slightly higher oil pressure compared to Castrol
> > GTX 20w50 when hot (190+ F) - about a 3 psi increase at 900 rpm idle. When
> > I switched, my idle went from 900 to 1200 rpm (since reset, of course) and
> > the mileage jumped from 29 to 33 mpg.
> >
> > I make no claims about the stuff - I'm not in love with it, I'm not
> > sentimental about it, I have no ego invested in it, I'm just reporting what
> > I found.
> >
> > YMMV,
> >
> > Jeff
> >
> >
> >
> > Jeffrey H. Boatright, PhD
> > Senior Editor, Molecular Vision
> > http://www.molvis.org/molvis
> > Mailto:jboatri@emory.edu
> > 404-778-4113
> >
> >
> >
>
> Ulix __/__,__ ___/__|__
> ..............................................(_o____o_)....<_O_____O_/...
> http://students.washington.edu/~ulix/ '67 Sprite '74 X1/9
Jeffrey H. Boatright, PhD
Senior Editor, Molecular Vision
http://www.molvis.org/molvis
Mailto:jboatri@emory.edu
404-778-4113
|