Will switching from Synthetic to Dyno oil harm my engine?

I have a 99 Altima with 66,000 miles on it now. I've been using Mobil 1
since 40,000 miles and to be frank I dont see the cost benifits to use mobil
1 on a "economical" car. Is it safe to switch back to dyno oil or will it
harm my engine?

thanks

 

There is NEVER a "cost benifit" to using sythetic oil. I hope you haven't
been trying to go 15,000 between changes? Switching back and forth isn't a
good idea IMHO but if I was going to switch back, I'd change to dino oil
and then change it again in about 1000 miles to help "flush out" whatever
was left and then change every 3000 there after.

 

Yes, it's perfectly safe to switch back (and forth again) if you want.
The oils are fully compatible with each other. If you change oil at
the usual too often intervals there is no real benefit to synthetic
except for really cold places if you have trouble cranking on regular
oil.
--
Elbridge Gerry, of Massachusetts:

"What, sir, is the use of militia? It is to prevent the
establishment of a standing army, the bane of liberty. . .
Whenever Government means to invade the rights and liberties of
the people, they always attempt to destroy the militia, in order
to raise a standing army upon its ruins." -- Debate, U.S. House
of Representatives, August 17, 1789

 

Maybe it's just that us AZ guys think alike, but the answer is "yes" - there
are no risks at all with switching from synthetic to dino oil. In older
cars, especially those with an uncertain oil change history or lots of hours
in hot environments (like Arizona, for example), switching from dino to
synthetic can dissolve deposits that old and hardened seals were depending
on. The affected seals can then leak - the same applies to using "engine
flush" products, as I found out the hard way when I was young and more
foolish.

Synthetic and dino are totally compatable, and blends are available. Some of
my friends use one quart of synthetic when they change their oil, and they
probably get most of the benefits of synthetic at a much lower price. In my
mind, the main value in synthetic is the much higher detergency. If oil
changes are kept up with dino oil, the engine itself stays clean inside, but
PCV passages and throttle bodies build up deposits that can be expected to
cause trouble eventually. In my 85 turbo Volvo, the turbo is still going
strong at 230K miles because of the regular oil changes, but I've had the
throttle body off for cleaning several times. I always have to use a drill
bit to clean the vacuum nipples when I wait more than a year or two. Last
year the actual hoses in the crankcase ventilation system plugged up with
deposits (these are like 3/8" hoses!) and I had to replace them. Lost 3
quarts of oil blown all over the engine when that happened on the freeway -
about a pint a minute. The Volvo gurus tell me these things don't happen
with synthetic.

Mike

 

No cost benefits? It depends. Changing oil less frequently when using
synthetic could be a cost benefit right there. If you live in a cold
climate, using synthetic makes startups easier on the engine, the starter
and the battery. 3 long term cost benefits right there. Wear and tear of the
engine is reduced. Another long term cost benefit. It has been my personnal
experience that gas mileage is better. My Chrysler minivan gave 27 mpg with
synt compared to 25 with dino. Another cost benefit. I once drove my minivan
a few hundred miles with an overheating engine caused by radiator that had
given its last breath. Kaput! I was in the middle of nowhere and had no
other choice but to keep driving. Arrived in Montréal area, I stopped at a
garage to have a new rad installed. The mechanic who did the work couldn't
understand how the engine was still running. Can you spell "cost benefit.?
And to answer you question, YES, it safe to switch back and forth.
JP

 

This nonsense has been around since the advent of synthetic auto engine
oil three decades ago. It wasn't true then, and it still isn't.

The only place synthetic oils have "higher detergency" is...in your mind.

 

It's perfectly safe. You don't have to do anything special -- no "flush"
of any kind is needed. Just make sure to use an oil of the viscosity grade
and service rating called for in your owner's manual.

DS

 

I use Castrol or Valvoline dino in my cars, change oil and filter (
Motorcraft Fl400-S) every 90 days or 3,000 miles, and have never had
an engine problem related to oil. n e v e r.

Go figure. If you want to spend the extra $ on synthetic, it's your
money, be my guest.

Lg

 

Old rumors are hard to kill.

Gotta agree there.

Oh, n btw, I run nothing but Valvoline full synthetic in both cars and
in my moorcycle. I change my oil about every 10,000 miles and it's
usually not even dirty enough to change then. If you change your oil
every 3000 miles, synthetic would be a waste of money.

 

Yeah, eh?

Agreed. Upon buying a 2.5 litre LeBaron with 70k miles on it, I put in
Mobil-1 10w-30. For the next 8 years and 90k miles, I changed the oil
every 10k to 16k miles (depending on conditions) and the filter twice as
often. It's still running on the original engine for the new owner.

Agreed *except* for extreme-hot and/or extreme-cold conditions.

DS

 

3000 mile oil change? Talk about things that will never die.

 

I've tried this on multiple times on multiple cars. I haven't been
able to find any negative effects going back to organic oil.

 

Older cars with small engines last longer with very frequent changes.
The newer models are designed to allow a longer period between
changes. But for those foolish enough to use ScrewyLube type places,
they get what they deserve even at 3K.

 

SNIP

Dino oil is, indeed, good. Nobody will deny it. But what other folks here
are trying to say is that a good quality synthetic oil is soooooo
muuuuuuuuch better.
;-)
JP

 

Hello every one I ran upon this group the other day. I live in Nebraska
where it is pretty cold at times. I have a "95 Sentra with 144k on it,5
speed. I just recently swithced to Vavoline Max Life 5-30. It is supposed to
be designed for cars over 75k, so far so good but is it worht the little
extra you pay? Any thoughts on this would be appreciated. Bill in Norfolk

 

This topic never fails to generate long threads, and I don't think many
people will change their minds. I'm no expert - I just pay my money and take
my choice. But these guys think synthetic is better than dino in nearly
every way - especially in cold weather:
http://www.autoeducation.com/autoshop101/oil-change-1.htm and succeeding
pages. Their take on oil change intervals is on page 9
http://www.autoeducation.com/autoshop101/oil-change-9.htm

Mike

 

I tried MaxLife once but didn't see any changes one way or the other. I like
Valvoline, so I may have used it a second time but after that the expense
just seemed too much. As the saying goes, "can't hurt, might help." Except
the price, of course.

Mike

 

I wave my left arm in a semicircle eight times every hour on the hour
between 8AM and 8PM weekdays (10AM and 12AM weekends) and have never been
attacked by a pink crocodile. n e v e r. Go figure.

Correlation does not imply causation.

Well, let's do the math, shall we?

Castrol or Valvoline's at about $2.10/qt including tax.
Mobil-1's at about $5.10/qt including tax.
An FL400S filter is about $4.20 including tax.

Let's say your car takes 5 quarts and you want to drive it for 60,000
miles.

If you're changing dino oil every 3k miles, that's 20 filters and 100
quarts, so $210 worth of oil and $84 worth of filters. Total oil costs in
60k miles, assuming the engine consumes none: $294.

If you're changing Mobil-1 every 9k miles, that's 6 filters and 30 quarts,
so $153 worth of oil and $25.20 worth of filters. Total oil costs in 60k
miles, assuming the engine consumes none: $178.20.

"Extra money" spent on synthetic: one hundred fifteen undollars and eighty
uncents.

-DS

 

Dan, if I read your post correctly (and I didn't check the math), isn't the
Mobil-1 regimen *cheaper* when compared to the dino regimen?

 

Shall we read it slowly?

one hundred fifteen undollars....