Saturn & synthetic oil?

First pardon me for cross-posting. It is not meant to irk anyone but to ask
as many people knowledgeable about GM cars as possible.
When I recently purchased my 2007 Saturn ION 2, the first thing I asked the
service people is when can I switch to syntetic oil.
They recommend waiting until at least 10-15,000 kms to make the switch and
use ONLY Mobil 1.
Just as if other companies don't make good quality synthetic oil. Sheesh!.
But I can live with that. Mobil 1 is excellent stuff.
What makes me perplexe is when they said not to use synthetic in the
standard transmission. I don't understand their reasons why.
So, is there anyone out there who can explain why I shouldn't use synthetic
gear lube?
Thanks

 

Your car is new so you can afford to wait and see for a year or two.

It seems GM uses mostly ATF and Synchromesh fluids in their manual
transmissions. ATF is synthetic, and I think the GM/Penzoil Synchromesh
is too. Synchromesh is good stuff and the fluid of choice for Mitsubishi
transaxles. If your transaxle uses 10W30, ask if you can run GM's
Synchromesh fluid in it instead.

If you do mostly short trips you should still change your engine oil
frequently (4 months/2000 miles) even when running synthetic. Frequent
short trips causes the engine oil to become acidic due to moisture.

I myself prefer Mobile 1 and is the only synthetic I will use in my
cars. My Dodge Stratus has over 137,000 miles on it, still sounds and
runs great, and gets me 31+ MPG on the highway. I lost an engine to
Amzoil many years ago and won't use any of their products. The engine
had 30,000 miles on it since being rebuilt, using conventional 10W30
oil. Three months after switching to Amzoil 10W30 the #5 main bearing
failed which also took out #4 rod bearing.

--
Gyz

07 Saturn Sky
98 Dodge Status ES
94 Mitsubishi Eclipse GST

 

I do not know of any good reason why you should not switch over
immediately to synthetic oil for your engine. I've heard the stories
of engines breaking in better with conventional oil. However, some
auto manufacturers use synthetic in their engines straight from the
factory (Daimler Chrysler). Also, the break-in periods for engines
nowadays is more like 500miles/800km, so I'm not sure why you would
need to wait 10-15,000km. I switched to synthetic (Mobil 1) on my
2005 Chevy at the first oil change without any problems.

 

Rings wont break in otherwise. I think when the C5 came out they had
some crazy long oil change interval for break in because it was filled
with mobil 1.

On a side note I do leave mobil 1 in cars up to a year or up to 3000-
4000 miles (oil filter is the limitation). The 3 month thing is getting
more and more outdated as API standards increase on conventional oils.
(for good running motors that is)

AFAIK all GM trans fluids now are synthetic or semi-synthetic. Look at
your owners manual. Does it say what it calls for and what the change
interval is? If it calls for new fluid within the warranty period change
it. After the warranty is up don't concern yourself with it again. Only
be sure it doesnt get low.

 

snip

Thanks for the info.

Snip

Are you absolutely, positively sure the oil caused the failure?
I have used Amsoil for many years and have had great results in my cars,
motorcycles and lawnmowers. I know other people who rave about it too.
In the early years, (early 70's), seals shrunk with Amsoil but seal swelling
agents solved the problem.
I think Mobil 1 was causing the same problems but I am not 100% sure.
Police fleets, trucks fleets, racers, etc, use Amsoil and other synthetic
oils with good results.
Did you have an oil analysis done to prove it was the cause of the main
bearing failure?

 

The car was a 68 Datsun 2000 roadster SRL311 (I was 6 when I bought it
:O). The engine had been rebuilt by the shop that I worked at (before I
started working there). The engine had 11:1 oversized pistons and a high
lift cam. I drove it hard, no doubt about that, and the previous owner
had even raced it a few times. It ran 30,000 miles on conventional oil,
probably Vavoline or Penzoil 10W30. Three months after switching to
Amzoil the engine failed while driving to work.

I told my Amzoil sales rep about the failure, and he gave me a number to
call them directly. They denied it was their product and would not even
come out and take a look. I knew I was screwed, and at the time I
couldn't afford to fix the car, so I sold it.

I have read that synthetic oil lacks some of the shear strength (correct
term?) properties of conventional oil. For example, the synthetic oil
blends for gear boxes are significantly different for this reason, and
not just in viscosity. It could be the engine would have failed running
any synthetic oil, but I doubt that. In my opinion Amzoil is just a
wanabe, while Mobil 1 has the expertise and patents to create the real
thing.

If you've had good luck with Amzoil, and you car is factory stock, you
have no reason to switch.

--
Gyz

07 Saturn Sky
98 Dodge Status ES
94 Mitsubishi Eclipse GST

 

Had to be the oil, racing does not wear engines very much. I'd guess a
typical NASCAR or USAC engine can go 100k with no problem as long as they do
the required oil changes.