I've been using crude based Castrol 5W-30 oil for my '94 Accord because
that's what my Honda Service used while I was taking my car there. The
Owner's Manual calls for various types of maintenance service at every
7,500 miles that includes oil change, of course. I've been also having
oil change only at midway of these mainteance intervals. So basically
I've been changing oil at every 3,750 miles.
Lately I've been wondering if I could save those "mid-term" oil changes
if I switched to synthetic oil. I'd like to hear some expert opinion on
that here and if the recommendation is yes, what type of synthetic oil
would take me as well to 7,500 miles as the Castrol crude based takes me
to 3,750 miles.
unless it's alaska or nevada, that's hardly relevant either.
at 3750, that's irrelevant too.
try to look at the big picture - the guy's almost certainly a troll
given that this topic has been beaten to death countless times before.
and you're not helping with your inconsistency between your
recommendation to stick to the owners manual on any topic EXCEPT oil
change intervals, where you go completely nutso and would have people
superstitiously changing their oil every day if you could.
You surely fall under the "Regular" maintenance interval, which calls for
an oil change every 6,000 miles or 12-months. The "Severe" interval calls
for 3,000 miles or 6-months.
Personally, I'm not comfortable leaving oil in for a year on an engine with
as many miles as yours. Have you considered changing your oil twice per
year? That would give you a 6,000 mile / 6-month change interval, which
seems reasonable to me.
However, you may also want to consider the possible beneficial effects of
your previous frequent changes. Your attainment of 300K is likely partially
due to those frequent changes. Older engines produce more blowby and load-
up the oil with deposits more than newer engines. It is wise to /increase/
the frequency of oil changes with age. My Integra has just over 380,000
miles on it. I change my oil at about 3,500-4,000 miles.
My "not comfortable" statement referred to the 1-year interval for
"Regular" service in the manual I have. I guess I should have put those two
paragraphs together so it was more clear that they were directly related.
My proposal for you was to change from replacing your oil 3.2 times per
year to 2 times per year. This would still be in keeping with the factory's
recommendations for "Regular" service..
that's an encouraging departure from "You can never change your oil too
you need to get some facts under your belt on this topic tegger. you're
happy to stick to the book on most things, but on oil changes, your mind
is completely warped. spend the money on oil analysis like professional
[aerospace, marine, military, railroad, haulage] engineers and fleet
managers do. and learn not to let superstition rule your life.
The downside of this strategy is that the cost of the oil analysis is a
significant percentage of the cost of an actual oil change.
So, how often should you do an oil analysis?
Just taking the sample is not trivial (or free). And my experience is that
the Post Office does not want to handle the samples via mail (even though
the companies that do the analysis all say the Post Office SHOULD handle the
For a while I would take a sample every other oil change (where I followed
the actual vehicle manufacturer's oil change interval recommendation, not
Jiffy Lube's). I never got back an analysis saying my oil was kaput. I
finally decided not to do the analysis any more since I was clearly not
exceeding the life of the oil given my driving parameters.
If I decided to go to greatly extended intervals, I'd take samples somewhere
between the vehicle manufacturer's recommended interval and my target to
narrow down what was safe.
For me it is just easier (and not much more expensive) to just go with the
vehicle manufacturer's recommendations for change intervals and oil
requirements. They appear to be very conservative. The Saturn Vue I owned
had the GM oil life monitor system. It never recommended an oil change
brefore 9500 miles and the sample I sent off after changes at this interval
came back as "good." (in other words, the oil could have gone a lot
further). My Sister never changed the oil in her old Civic before the
odometer driven reminder turned red (7500 miles) and while the rest of the
car was a rolling POS at 150,000 miles, the engine ran like new.
The excessive oil change habit is hard to break. It took me 25 years to
break it, but from now on, it is the manufactuer's normal service schedule
and recommended oil for me (if they say synthetic, then I'll use it,
otherwise, I'll use what I consider the best quality conventional oil).
so let's see. at about $25 for 5 quarts of synthetic and $25 per test
at blackstone, if you're someone like tegger changing their oil 4 times
a year on a 12k mile annual, you can change your oil, test it three
times, and still be even. change it once and test it once, and you're
$50 ahead. i don't think cost is the issue.
do it a couple of times to see what your numbers are. more if you're
trying to maximize, but three should get you what you want - your own
reliable change schedule based on your own typical usage.
eh??? all you do is stick the bottle under the oil stream next time you
do a change. and if you're taking it to iffy lube, they'll do it for you.
how strange - my experience is that they definitely will. take the
pre-printed blackstone letter with you if you're having a problem.
you and most of the rest of the nation.
most people are better focusing their angst on crappy oil filters -
there is some real garbage out there. even oem. usa-made honda oem
filters for instance almost always have defective anti-drainback valves
after just a few thousand miles. even cheapo walmart [champion labs]
filters do better than they do.
wix are the way to go for me.
both engine management systems and engine oils have moved on since the
1950's when the 3000 mile change was recommended. you need to too. use
ordinary oil and go ahead and change it per the owners manual. if you
want to use synthetic, you can exetend that period considerably.
if you don't believe, pay for oil analysis and get the hard facts for
yourself. [it's cheaper than paying for constant oil changes like
you're doing now!]
oh, and most "synthetic" oil these days is mineral based. a little more
refined maybe [they call it isomerization], but mineral based
nevertheless. don't get suckered into the hype unless you know what
you're doing. or paying for.
I can't get excited about synthetic...
With modern oils, the big issue is contamination. (The oil itself is
still a wonderful lubricant come the end of a change cycle.)
Synthetics get contaminated just like any other oil.
If you care about the car, plan to keep it a long time and/or make a lot
of short trips, change more often!
If not, take the change intervals out.
There are way to many variables to cover in a post here... but I'd stay
with the mineral and save the money. Keep in mind that oil is cheaper
than metal any day.
PS, Look at your manual again and see if it says something about severe,
dusty conditions or some similar wordage... it probably does. Those
recommendations more 'real world'.
After about 180,000 miles with Mobil 1, I find it absolutely astounding
that the head is still shiny-silver inside. No varnish. At all. Synthetics
seem to produce far less varnish than mineral oils, and to be much better
than mineral oils at keeping contaminants in suspension.
My head gasket failed after the first 200K, which were passed with Castrol
GTX and an oil-change interval of not more than 3,000 miles. When I got the
car back, the head had been totally cleaned of all the brown varnish which
had previously been there. At that point I switched to Mobil 1, and have
not looked back. I've owned the car since new, so I know exactly what's
been done to it over the years.
I forgot to to answer the OP's question regarding synthetic oils. And my
answer is, "The stuff is awesome! Use it, for sure!".
Yeah, well some of us find that varnished finish on the engine's innards
attractive. Reminds me of how nice the wooden hull, mast, and boom
looked on my old 1950's vintage sailboat after I refinished them each year.
Hell, next thing you know, I may have a sign painter put a name and home
port across the trunk of my Accord...
WHOA.... a while back, some said in another newsgroup that using
synthetic on a older car (same engine not rebuilt) might produce some
leakage since the stuff is thinner. Personally I'd go with what the
manual states or more frequently and never look back. This oil
analysis advice is un-necessary for most people.
The idea that synthetic will cause oil leaks is ancielnt wisdom that no
longer applies to the sort of synthetics you buy today. Once old (and
possibly incorrect) old knowledge gets burned into the collective mind it
seems impossible to eliminate. What might have been at least partially true
for the original Amsoil and Mobil synthetics from 30 years ago, no longer
I agree that if you are going to follow the vehicle manufacturer's oil
change schedule, an oil analysis is not needed (unless you just want to know
and / or overcome your fears that lead to ridiculously short oil change
intervals). However, if you are looking to go to extended oil change
intervals, then they are a good idea.
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