I have been taught by my oldskool dad to NEVER use synthetic oil....that regular ol' Valvoline is the best, lol. Well all my friends use synthetic in their new GTO's , Vettes', ect....and when they drain it, the stuff still looks NEW!!! I was wondering if it would hurt anything to go from regular oil to synthetic on a car that has ONLY seen regular oil and has over 60K on it?! Whats your opinions on synthetic vs regular while your at it. This is a 96' z28 so I am talking the LT1. Thanks for your time---

 

do it up, you can go back and forth from synthetic to regular and you wont see any problems.I do it all the time, I usually run syntec 5W30 in summer and put plain regular oil in for the storage months.

 

Their is no harm in running synthetic lubrication at all. I sell AMSOIL, http://www.karsnkwb3.com, and have used it in all my cars and my Z ever since i've had them. I abided by the 25,000 mile interchange (you still have to swap filters at about 12,500 cause the oil will outlast the filter if it's a mechanically sounds engine and also you need to use top notch filters like the AMSOIL filter or Hastings). True synthetics (Castroyl Syn-Tec isn't synthetic, they just took hydroprocessing to the next step giving it synthetic like qualities) are lab created compounds, not refined. They consist of short carbon strands, not long carbon strands. They hold their viscosity better under temperature change and wear. You're best synthetics are you PAO (polyalphaolefin) base stock synthetics. PAO is extremely hydrogenated (the olefin-carbons are saturated with hydrogen) thus giving it extreme thermal stability. Thats why AMSOIL projects a 25,000 mile oil change with their full synthetic and Mobile 1 with their 15,000 oil change. Oil itself doesn't break down, it's the contaminants within oil that break down and oxidize and become acidic. With synthetics, it's all lab created and very very few contaminants find their way in it. But with you basic basestock 2&3 oils (which are mineral oils and the most commonly used in automotive applications) they are refined with contaminants and impurities already in them. So thats why you can only get 3,000-5,000 miles with them. Also, synthetic basestocks will give more usefulness to additives. In such, this means that they can cut back on anti-oxidives and such and worry about more detergents to keep any kind of build up that might happen from happening.

So from that whole speel, it is completely safe to run Synthetics, and majority of synthetics on the market won't void warrenties (AMSOIL and Mobie 1 doesn't). The great debate between which oil to use is a matter of personal opinion. I bought some AMSOIL a long time ago to give it a shot and ran a S.O.A.P on it after roughly 25,000 miles and the lack of break down (i.e. iron, aluminum, nickle content) convinced me to swtich and thats why I became a dealer. But let me make this clear, i have recieved some bad complaints about AMSOIL, not that anyone on here is stupid, but WHEN MANUFACTURES RECOMMEND A CERTAIN PROCESS OR APPLICATION, IT IS THE BEST CHOICE TO FOLLOW THEM AND NOT HEARSAY. The people that have the most trouble with AMSOIL (from my experience) have not followed manufactures specs because they thought some how they were smarter than the manufacture or they used it in an application that was not mechanically sound. I can truthfully say I have never had one complaint from a client where they used AMSOIL by manufactures specs and in a mechanically sound engine.

 

Wow, that helped me ALOT. I read on this site in another thread, that if you have worn seals and gaskets with micro holes in them , the synthetic may start NEW engine leaks. I guess since the synthetic molecules are smaller, and can fit through the micro holes!? Do you agree? Thanks again---

 

I did it and have had no problems. If you have seals or gaskets that are close to leaking with regular oil and change to synthetic you will probobly get some leaks.
My drain plug began to leak when I changed and I got a few drop near the front of the pan.

 

My rear main started leaking when I switched it to Mobil 1 when I bought the car, previous owner used regular oil. No nig deal, the switch was worth it. I have the motor torn apart right now and it looks excellent inside. Either way you go, it'll be fine, but there really isn't any reason not to run the synthetic.

 

That's exactly what I did. I got the car at 60k and immediately swtiched to fully synthetic - Mobil1 (no real reason). At the time I wasnt fully aware of the possible consequences. Switching to syn on an older car sometimes does open up small leaks. I was lucky enough not to have any. The car's been running great for 40k now.

 

Great, thanks alot guys.....my one friend SWEARS by Mobil one and said that Walmart is having a sale right now, lol That will be my next stop today---

 

Wal-Mart, here I come. Thanks for the heads-up!

 

6SpeedShifter - How many miles do you have on your car? Let me know how it goes. My dad was the same way... I told him I thought I'd go with synthetic and hes like no your not.

Plus I didn't want to mess with a gasket overhaul or leaks so I went with mobils "clean 5000" non synthetic and to tell you the truth it looks VERY thin and I didn't have any problems using it... I think the previous owner used Castrol, he wasn't really sure.


Anyways, LMK how it goes and how many miles u have on your car? I have 130k so it isn't exactly new. I think mobil suggusts you should only run mobil1 on new cars.

 

I've got 196,000 miles on my car, and the previous owner used the regular old auto zone stuff.

I'm guessing I should just stick with regular oil then right?

Once I get it rebuilt though, I will probably go for synthetic.

 

This is kind've my position. I'm just gonna run what I put in it. After college when I build my 355 I'll switch over to synthetic.

 

If your car isn't of high milage, before you switch over run some engine flush throught their to break down and build up that might occur. BE CAREFUL, i wouldn't do it to a car that has 90,000 or over on in cause it could cause break up that has occured to wash away and expose some leakage areas. And the reason that synthetic has recieved that view of making leaks or bringing them out is cause it can maintain is viscosity level with more efficiency than conventional oils More even viscosity means more chances to uncover any nice little cracks and holes.

 

I currently have 106k and have been running synthetic for the last 46k. At the time that i switched, I didn't know much about the dangers associated with such change. Maybe I am just luckly. Anyway, now that I am more educated on the subject, I firmly believe that it doesnt matter what oil you use (synthetic or not) as long as you change it regularly. This being said, if I could go back those 6 years, I never would have switched to synthetic.

 

I use both at the same time.

After break I chnge the oil and put 3 quarts of Dino oil in it and 2 quarts synthetic.

The dyno oil has some properties that synthetic doesnt and on a regular oil change schedule the dino oil will maintain it's viscosity easily with the help of the synthetic.