Oil help sythetic or nooo

I bought my v6 grand prix gt and forgot to ask the dealership if they had used or if there was ever sythetic oil used in the engine. I mad my first oil change on it and kinda have noticed a difference in the way its driving. The car has about 100,000 miles on it. I have to do my next oil change and was wondering if i should put the sythetic in or regular again? and if i add sythetic will it cause leaks because of the mileage. and if the engine always used sythetic and i start adding regular oil will it screw it up? What do you sugggest.


thanks

I bought my v6 grand prix gt and forgot to ask the dealership if they had used or if there was ever sythetic oil used in the engine. I mad my first oil change on it and kinda have noticed a difference in the way its driving. The car has about 100,000 miles on it. I have to do my next oil change and was wondering if i should put the sythetic in or regular again? and if i add sythetic will it cause leaks because of the mileage. and if the engine always used sythetic and i start adding regular oil will it screw it up? What do you sugggest.


thanks

GM dealerships do not normally use synthetic motor oil unless specifically asked for by the customer or there is a requirement for it so high probability it is regular dino oil. Do not mix synthetic with regular and vice versa.

You can switch to synthetic even with 100K miles but make sure all the existing seals like valve cover, oil pan and front and rear crank seals are good first. If leaking technically you should replace them first before using synthetic. See info below which covers the causes leaks myth.


Source: Amsoil

Converting really high mileage engines:

Very high mileage vehicles may still be good candidates for conversion to Amsoil synthetic if they have been well maintained and are in good condition.
If you have no visible oil leaks or oil burning/consumption try this: drain the old oil and change the filter. Install new petroleum oil and a new oil filter and drive the vehicle till it is thoroughly warmed up. Now add the Amsoil engine flush and use according to directions on the can.

Flushing the engine with new oil and filter will give you the best possible flush. The new oil and filter can hold more contaminants and give you a cleaner engine. Drain the oil/engine flush, change the filter again and install the Amsoil motor oil of your choice.

As the newly installed Amsoil synthetic motor oil continues the process of cleaning the engine, deposit's; some of them microscopic will be removed leaving microscopic voids. Over a period of time the additives in Amsoil will fill in and reseal these voids. This process can take a few hundred to several thousand miles depending on the mileage and condition of your engine.

During this phase some engines will have slightly elevated oil consumption till the engine is cleaned up and the voids filled. This is normal and only last for the time needed for the oil to condition and clean the engine.

Most people don't even notice this phase and usually oil consumption ends up being much less because Amsoil synthetic motor oils are so much less volatile than petroleum oil (does not evaporate at high temperatures)

The "synthetic oil's cause leaks myth":

Synthetic oil does flow more readily than petroleum oil does so if you have a leak it will tend to leak from it more freely. This however is caused by an all ready failing seal. Not by the synthetic oil itself.

Petroleum motor oils are notorious for forming what's know as a "false seal" Varnish and crud will build up around a failing seal and help keep a more viscous petroleum oil from leaking. Synthetic oils that are highly detergent will clean off the build up and expose the all ready failing seal. There's your leak!

For this reason we suggest that our oil's only be used in mechanically sound engines. If you have a leaking seal replace it prior to installing Amsoil motor oil.

We have also seen many cases where older engines are starting to seep oil because some motor oils have poor long term seal compatibility. Exposure to these low grade oils causes the seals to harden and seal poorly.

All motor oil, synthetic and petroleum alike contain chemicals as part of the additives that are added to the oil that are there to keep engine seals pliable and to cause mild swelling so the seal works properly.

The additive's in Amsoil motor oils are so good at conditioning engine seals that there have been many cases where engines with slight oil seeps sealed back up after a few thousand miles of driving. That being said if the seal is shot all you can do is get it fixed, no oil will fix it ours included.

Personally, I think you can mix any combination of synthetic to dino and not notice any difference from the driver's seat.

Your wallet is guaranteed to notice the difference at each oil change interval.

My thoughts are that millions of vehicles have driven billions of miles on dino oils. If you have the need to take advantage of the "good" properties of synthetics (typically related to high-temp service) then the extra cost might be worth it.

The beauty is that everyone gets to make their own decision.

Morons or anyone without common sense probably wouldn't. :lol:

The main reason why the two should not be mixed as a general rule or practice is because oils are complex mixtures of additives and base oils that can be destabilized when mixed. Obviously there are synthetic blend oils available which is a mix of mineral and synthetic oil but it is done by the manufacturer in the proper ratio. Last time I checked a container of Mobil 1 synthetic motor oil it recommended not mixing the two so I'll trust their expert judgment over anyone elses.

oils are complex mixtures of additives and base oils that can be destabilized when mixed.

That's a new one on me that engine oils can be destabilized by mixing. My simple thoughts are that a synthetic oil has a synthesized molecule...so all the molecules are the same.

As opposed to a dino oil which has a range (bell curve distribution if you like) of molecular weights.

The high temp service of synthetics (again in my thinking) are because the very ends of traditional distribution aren't in play: lighter molecules don't vaporize and heavier molecules don't "crack".

I use synthetics in 4-cycle air-cooled engines. That is all.

One or the other, DO NOT MIX.
I personally would stick with the conventional oil especially not knowing the past. Changing to synthectics at this point may cause leaks and unusual wear. Pick a good oil and stick with it. It may take a couple of changes to get things in line but it will work out.
Check the following website for an educational insite.
www.machinerylubrication.com (http://www.machinerylubrication.com)

Changing to synthectics at this point may cause leaks and unusual wear.

This is incredible. Somehow going to another "SM" or Service-M class oil, although one with a synthesized petroleum molecule is going to cause unusual wear?

I think you are recalling the old farm tractor stories of people who ran non-detergent oils for years on end, filling the crankcase with sludge, the tractor was parked for 10-50 years and some enterprising restorer came along, filled with the latest 10W40 (detergent) which promptly starts trying to "dissolve" the sludge (or at least entrain the particles) and carry it to the filter to be removed. Lube system problems can then develop.

As mentioned in my post. The website that I directed you too, takes an educational insite on the realities of different base stocks and additives. There are numerous articles on this web site to be obtained with detailed explanations and views. This is not an effort to sway you one way or the other. It is more of an avenue of different point of views to help you make a decision.
Everyone has an opinion and I respect yours.