SSZ2891

What are the benefits on synthetic oil in our cars. Personally I have a 90 305 TBI 5 speed Camaro. Write your thoughts on advantages to the use of synthetics. Any notable performance differences felt? Worth the money? What are the best.. Mobil 1?

Air_Adam

The inside of both my old 350 and my LT1 are spotless - look brand new inside. My LT1 has used synthetics most/all of its life, and my 350 has since I finished breaking in the new cam a few years ago. Both have a rear main seal leak, but otherwise never lose any oil, and the oil only starts to get dark around the 5k mark... I usually change it at 6-7k, and it still comes out pretty clean. This is the main reason I use synthetics.

They both start easy and build oil pressure right away even when its -40* outside too, so it stays fluid even at really stupid temps.

For a mild street driven SBC, you probably won't notice any real difference between the name-brand full synthetics. Use whatever you have in a weight you like. I use a 5w30 in the LT1 in the summer, 0w40 in the winter, and 10w30 in the old 350 (only really sees summer use now).

SSZ2891

what about if it has 130000 miles on it and just start using synthetics now. some people say that it might clean away the gunk around gaskets and lead to leaks...

wildjyoung

iTrader: (6)

That is true, that sometimes using a synthetic will clean and cause leaks. However, synthetics contain "swelling agents" that cause the seals to swell. Perfect example is my 1994 Trans Am with 105,000 on the LT-1. I just bought it and switched to synthetic. It developed a leak for about 2-weeks, which then dissapeared.

You are not going to hurt anything by going to synthetic. Whatever anyone tells you, Synthetics are not thinner, they will not harm your engine. At the same time, they will not necessarily add to HP. Air Adam is exactly correct in what he told you.

Saabster

iTrader: (2)

Yeah, synthetics are just better lubricants. If you drive your car hard, like a lot of people on these sort of forums, I think it's a worthwhile investment.

SSZ2891

so what would you say as far as brand. does it matter or are all synthetics basically the same.

Saabster

iTrader: (2)

Them is fightin words.

five7kid

iTrader: (14)

Yes, it matters, because no, they are not all the same.

The "major" brands like QS, Vavoline, etc., use a "Group III" type "synthetic", which is just hydrocracked petroleum. They wouldn't be called "synthetic" at all if not for U.S. regulatory fiat, a non-technical decision that declared that "highly refined" is essentially the same as "synthesized" (The U.S. is the only country in which Group III lubes are allowed to be marked as "synthetic"). Group III are cheaper to produce, have better properties than "standard" petroleum-based lubes, but inferior to "Group IV" PAO true synthetics. The bad news is you can't tell by reading the bottle what you're buying.

The brands with PAO's are Mobil 1, AMSOIL, Red Line, and Royal Purple. However, both Mobil 1 and AMSOIL have at least one line that is Group III.

wildjyoung

iTrader: (6)

I have heard that the "Holy Grail" of synthetic motor oil is German Castrol. It is 100% PAO with a really good additive package.

It is a 0W30 that is from teh Castrol Syntec line. However, it shows European formula on the front and stated made in Germany on the back of the bottle.

I H8 WWD

iTrader: (5)

I use Royal Purple 10W-30 (10W because its my first Synthetic oil change). Might switch to 5W30 afterwards if no leaks are formed for cold starts and it is was is recommended with my motor.

My buddy blew up his Ford SC (over rev), drove it over 5 miles without any oil and it was fine upon tearing the motor down. Not the parts that blew up, but the parts that didn't were fine, and still had a nice slick oil on them. He used Royal Purple. So this is one test that I was actually able to see myself which aided me in my decision for Royal Purple.

five7kid

iTrader: (14)

I had a similar thing happen with an '80 Citation, except the oil pump committed hari kari and I didn't realize it for 5 miles, and I was using AMSOIL. This was the day after the car turned over 150,000. I pulled the pan, fished out the broken oil pump parts, checked the bearings (they all still had a film of oil on them), installed a new oil pump and oil pump drive shaft, ran the oil I drained out through a paint filter and put it back in the crankcase. The engine ran fine for another 100k miles with oil changes once a year before the body fell apart around the engine.

el_muerte

Because synthetics don't break down as rapidly as mineral oils, you can go a lot longer without changing your oil, although you should still do the filter at the regular intervals. I heard of one guy who ran Amsoil in his car for something like 100,000 km, getting a sample analyzed every 5000 km, and it held up fine, though it's definitely not something I'd recommend doing.

ncmail

I would rec commend Amsoil. I used it for a few years and fell in love with it enough that I am now an Amsoil dealer.