Can I switch back to synthetic oil without flushing?

Okay, here's the deal, bear with me it may be hard to explain:

At around (just guessing) 5000 miles I had my new Honda serviced and
they recommended I change the oil because even though it was only 5000
miles it was over a year old. They explained that this would make the
car run better and last longer so I went for their medium grade
synthetic oil.

Then, about 5k later I took it back to the same dealer and asked for
an oil change. Not knowing that you shouldn't change back to regular
oil without flushing I told them to put in regular oil. They did.

Now it's 5000 miles later and my light came on for the first time
indicating 15% whatever, for an oil change. I mentioned that I had put
synthetic oil in it once but now am thinking of sticking with regular
oil.

But the guy told me that synthetic oil and regular oil don't mix and
any time you start with synthetic oil, you have to stick with it or
else do a flush first. But then he said, "But with synthetic oil you
don't need to change it as often, so you don't really need an oil
change even though your light came on."

As you can imagine I am now totally confused.

First of all:
Shouldn't the dealer have told me the first time that once I started
on synthetic oil I had to stay with it forever or else flush the
engine?

2nd: When I took it in for the 2nd oil change and told them to put
regular oil in it after they had put synth. in it the first time,
shouldn't they have told me, then: No, we can't do that. Your car has
synthetic in it, so we can't put regular oil in on top of it.?

3rd: Why did my light come on, saying 15% if I don't really need to
change the oil? Is it set according to time, or according to how the
oil is breaking down? (The guy at the shop today said it was just set
by time, to light up after 5k miles. But if that's the case, why has
it never gone off before now? (I have a little over 15k on it.)

4th: How many miles SHOULD I have gotten on the synthetic oil before
changing it? And now that I have changed it anyway, what damage have I
done by switching back to regular oil, and next time should I go with
synthetic or regular??

I think someone is b.s.'ing me. Is it the dealer who sold me the synth
in the first place, or is it the mechanic who is now telling me I
should always stick with synthetic oil and can't change back to
regular oil without flushing first? And since I have already changed
back without flushing, what harm was done?

 

Total BS. Maybe at some point in the distant past there was some truth
to this, but these days, there is no reason to care.

http://www.mobil.com/USA-English/MotorOil/Car_Care/AskMobil/Flushing_Engines_Prior_Synthetics.aspx
http://www.mobiloil.com/USA-English/MotorOil/Oils/Oils_FAQs.aspx#Mobil_1_Extended_Performance_FAQs5
http://www.mobiloil.com/USA-English/MotorOil/Car_Care/AskMobil/Switch_Shorter_Drain_Intervals.aspx
http://www.mobiloil.com/USA-English/MotorOil/Synthetics/Myths.aspx
http://www.amsoil.com/frequent.aspx

Ed

 

Thanks for the reply and links.
I called Honda and confirmed that I had indeed switched back to
regular oil last time I went there.
The guy there assured me that the type of synthetic oil I had used in
the first place was something like a "half and half" type and so it
allowed me to switch back and forth so there was no harm in switching
back to regular oil last time.

However when I told this to the independent mechanic who is servicing
my car today, he said, "What? That's crazy!" But I assured him that I
had already switched to regular oil last time so I may as well use it
again this time.

I read some of the threads about synthetic oil and it sounds to me
like it's controversial at best, in terms of whether or not it is
really "worth" the extra money. Since regular oil changes for my car
go for around $22 on sale and synthetic goes for about 3 times that, I
am skeptical as to whether or not it's really worth it, especially
when I am the kind of person who changes his oil every 3-5k instead of
the 15k so Honda recommends.

One question though: Using regular oil (OR synth oil) is there any
problem with changing it TOO often? The guy at Honda last time said he
really didn't recommend I change it after 5k miles, and I was kind of
shocked that he would say that given that usually they are looking for
ANY way to get me to spend more money there...

 

no, you called the dealership--an independent small business, not
related at all to American Honda Motor Manufacturing.

He can do pretty much whatever he wants as he services your car.

Honda didn't sell you a car, and Honda doesn't service your car.

 

There is no substitute for actual facts. Get your oil tested by
Blackstone Labs, do it at varying intervals, and find out exactly what
YOUR driving patterns and car demand with respect to oil changes.

Who's asking--you or your wallet?

Other than paying more money for something that may not be necessary, no.

See my above suggestion on testing your oil. Get the FACTS.

 

No, because that's not true. Mineral and synthetic are perfectly
miscible.

Some less-expensive "synthetics" are a combination of mineral and
synthetic.

No, because that's not true. Mineral and synthetic are perfectly
miscible.

Some less-expensive "synthetics" are a combination of mineral and
synthetic.

What model have you got? What country do you live in?

The second guy. But he may not be BSing you; he may be genuinely misled.
A lot of people believe that nonsense.

None whatsoever. You can change from one to the other with each oil-
change, if you wish.

 

Nope. That's a /good/ thing for your engine. The more the merrier.

 

Correct! The DEALER did those things.

The dealer is NOT "Honda". They are a totally independent company that owns
a Honda franchise. They can sell you anything they like, whether Honda
approves of it or not. Franchise laws tend to tie automakers' hands when it
comes to this sort of stuff.

 

indeed!

 

daily? weekly? superstitiously?

 

the guy's just trying to sell you the more expensive stuff -
particularly because you've been talked into it before.

conventional/synthetic oils are completely intercompatible. synthetics
are often better, but i'm not sure it's not worth using them if you're
going to change the oil that frequently.

stick with whatever you prefer. imo, synthetics are worth the money
because they have premium additive packages that keep your seals in good
condition, last much better, they do provably protect better, and they
offer slightly better fuel economy. if you're going to use them, leave
them in for the full manufacturer specified change interval or the one
per the engine computer, not this 5k mile nonsense.

and do NOT get an "engine flush". very bad.

 

But don't you have to take it back to the dealer you bought it from to
get warranty service, even if that means towing it across the country"
(For those noobs, this was a very old, tiresome and, eventually,
fruitless thread with an idiot that thought that the dealer warranted
the car, but that the company sold it to you. I think Tegger gave up
on the fool before I did. So Tegger is much smarter than me. Trust
him.)

--

- dillon I am not invalid

Toby (Tri-Umph That's the Sweet Truth)
March 1998 - June 2010
What a dog. What a dog!

 

oh, man, I'd forgotten about that.

That wasn't Al, was it?

who was that...?

 

I consumed a great deal of alcohol during that period, mostly to
forget the turd. But he's gone and we're not.
--

- dillon I am not invalid

Toby (Tri-Umph That's the Sweet Truth)
March 1998 - June 2010
What a dog. What a dog!