synthetic oil is the only thing that has been used on my 98 lumina since it had its for oil change down (i bought it from a guy who got it from his dad who had it as a work car)
It has 230+ and still runs very strong, i would drive it anywhere.

Do the synthetic oils really maintain the engines life longer?

also, i got an 02' blazer with 43k on it, i got it when it had 40k. As far as i know only regular oil has been used.

what do you guys think about switching to synthetic? Do you completely put 5/6 qts of the syn in or i have heard you should do it a qt at a time until you reach the 5th oil change. My friend had a 98 blazer and switched from synthetic to regular a few times and his motor blew up.

just curious, any help will be appreciated. I will stick to the paint and leave the enternal engine ?'s for you guys!

 

Oil will not cause an engine to blow. The main difference between synthetic and conventional is that synthetic is much more pure. Due to this, they are much more stable at the extremes.

I switched my Bravada over when I bought it with 72k miles on it and never had a problem caused by the type of oil. I switched my old Intrepid over at 96k miles and proceeded to put another 100k on it with synthetic changing the oil every 5-6k miles and that car didn't use a drop of oil between changes. I will not hesitate to change over my new Rainier to synthetic at my next oil change.

I don't think your friend had a problem that was caused by the oil. Simply put, oil is oil.

 

The thing is, you can't switch to synthetic, then back to regular, because there are chemicals in the synthetic will allow the rubber and fittings in the oil system to function properly, but when you switch back, the fittings and rubber parts become brittle, sometimes crack and usually leak. This could put deposits in your oil system and if the motor does not get enough oil cause the motor to burn up and sieze. This is what I have learned from my American Oil Changing Association Training I had when I worked at Saturn/GM. So once you switch stick with it.

-Lenny

 

Please show me a source that states that you cannot switch back and I'll believe it, but everything that I have read suggests nothing of the sort. And I myself have made the switch before without issues.

BobistheOilGuy.com is a great resource for information.

Here are a few articles found there:
Racing Oils - Has some information on how engine oil comes together.
Synthetic Oil article from Detroit, Michigan Truck and Automotive Engineers

 

Ive heard that you cant go from synthetic back to conventional. But dont have any sources that say you can or cant. I know i wouldnt try it.

my only problem with synthetic is that it seemed to make my engine louder. guess it could be the oil i used or maybe its just me.

 

I don't have any sources I could link to you, but from the training I recieved, which I admit was from a dealership, and the stories I have heard from people, it is just better to not switch between the two. Evidently the synthetic has some sort of chemicals in it that reside when you switch back to regular oil and then those two mixing together or some bull**** eats up gaskets and what not in the engine/oil system causing them to go bad and then if you are not paying attention to them, like most saturn owners (IMO from my experience) you run out of oil and overheat or seize an engine due to lack of oil. just my opinion. I would rather play it safe than sorry.

-Lenny

 

I ran conventional in mine for quite a while and then switched to Syn. I've heard its better to go form conventional to synthetic blend, and then to fully syn over the course of about 4 changes.

 

At about 122k miles, i switched from regular to synthetic (Mobil 1). After about 2000 miles, i was down a quart of oil, after never burning a drop before going to Mobil 1. I switched back to conventional oil after that and everything is back to normal again.

I've read the research and all... but with my one experience of switching from conventional to synthetic, it didn't work out too well.

 

I know this is an older thread, but I'm thinking about going to synthetic and had a question. I have 140k on my blazer right now and would like to switch, but I heard it not a good idea to switch when the mileage is that high. Anybody have any experience switching with higher mileage?

 

There is just so much misinformation, urban legends, and old wives tales out there about oils. You can switch back and forth from syn to dino oil if you choose without any damage to the engine. The only issue might be that going to syn will soften some seals that have hardened over time and loosen some crud that was attached to them, causing it to leak past and creating a temporary oil leak. This should disappear after one or two oil change cycles.
That being said, the 4.3 engine just does not require the use of syn oil. You're not going to see any measureable and verifiable gas mileage increase. Any quality dino oil will keep these engines perfectly happy. Check out the threads Kyle posted in his reply.