I don'tk now of any car that takes 6 quarts....

In the words of Smokey Yunick, a legendary NASCAR engine builder, organic oils are as antiquated as the Model T. I agree. Synthetic oils hold up at higher temperatures for much longer periods of time than organics. Organic oils can not stand as high of a temperature range as synthetics. Therefore, organic oil can actually dry up (like form a heavy residue and film on everything) and clog up the engine. Synthetics will hold up to higher temperatures for longer periods of time without breaking down and I believe everyone should run it if they can afford it. But make sure you get a full synthetic. If you're not paying about $6 a quart, you're not getting a real synthetic. There are these refined "mineral" oils or something to that affect that are refined organic oils, which are still better than regular mineral oil, but it's just flat out scamming to call it "synthetic" because a true synthetic is "lab grown" for the purpose of lubricating an engine....

 

Plenty of cars take 6 quarts.

My Dad's 02 Mustang GT takes 6.5 Quarts.

And I am pretty sure that the 06-07 Monte Carlo SS 5.3L takes 6 quarts.

 

I'm sure it will last 5,000 miles but most conventional oils will these days. Try it in your car and see how well it likes it. See if the engine is quiet or not and if you use any oil while running it. Last I knew, Mobil conventional oil is what GM uses from the factory.

As far as claims that synthetics can go longer than conventional, that depends on what oil analysis shows. Every engine is different and what might work great in one engine, might not work great in another.

I've posted before why I don't like Mobil 1 and in my case oil analysis did not support doing extended oil changes with Mobil 1. My engine did not like the stuff and it was noisier using it and it used more oil than when I ran conventional oil. I wasn't getting my money's worth so I went back to conventional oil. I'm not saying I wouldn't have had better results with a different brand of synthetics but with the great oil analysis results I was getting with conventional Chevron oil, I saw no need to change.

I see a lot of people on various websites saying that X brand of synthetic oil can go X amount of miles with no proof to back it up. I bought into the talk until I actually did a series of oil analysis over a period of time and realized that in my application, extended oil changes with the synthetic oil I was using wasn't going to happen. Sorry for the long post and good luck with whatever you use.

Wayne

 

sorry when i wrote that i missed where you said 4 quarts. i do not have an owners manual, partially why i got a deal on my car, but have one in the mail. im sure they last for more miles and run cleaner but i swear ive read on hear that they reduce mpg's. i have a lead foot and my tim's don't help either. i only get 20 as it is, so im cautious about the syn. thanks for the replys.