Please give Pros and Cons on Synthetic motor oil. I have my 91 FB, and was told because of the low miles (73,plus) I should switch to synthetic at my next oil change. Opinions please.

You can find pages upon pages of info about this over at the Fullsizechevy.com forums. You don't need to switch to synthetic. Synthetic is much more expensive, and is higher quality, longer lasting. It has great detergent properties. However, regular ol' dinosaur whiskey works just fine if you regularly change oil, keep a clean air filter, and don't want to pay $4.00 a quart or more. Synthetic will free up a few horses, maybe 5-10, which is truly remarkable just by switching lubricants. If you want the additional life-span per oil change and a few extra ponies, it's worth it. If you don't want to pay for it, non-synthetic works great.

Be careful what you ask for. These oil debates sometimes get very heated.

I've done tons of research on this topic - and came to two inescapable conclusions:

1) There is no such thing as miracle oil.

2) Synthetic has a slight edge over dino oil, primarily because it offers superior wear resistance, and it's molecules do not break down with age or heat.

I just started using Amsoil in my '87 DeVille with the much maligned 4100 engine. It gets driven about 6 thousand miles a year, and I change the oil once a year. The filter gets changed at 6 months. It's been in there for 2500 miles so far, and I plan to start sending samples to the lab for testing every thousand miles after the 3K mark. If you want to follow the results, check out my blog at www.cadquest.blogspot.com (http://www.cadquest.blogspot.com)

Though all of our vehicles have always been on the "classic" oil with 3k change intervals like a religion, twice my father did a Synthetic blend in the '93 Fleetwood and the damn thing was transformed--ran like a scared rabbit and definately felt like the engine had been freed up a bit.

It wasn't a monumental difference, but it was immediately noticeable. Switched back to the old stuff the next change and have continued to do so ever since. Still has serious balls to it, but isn't as "zingy" as it was with the Synthetic.

That experience, plus the fact that it tends to keep things a little nicer inside the engine, has led me to think that I myself will probably become an all synthetic user, but we'll see...

I never noticed any difference in performance by using synthetics although I'm sure there could be. I just switched to synthetics on my Fleetwood and plan on changing the oil after 5k miles worth of use vs. the standard 3k. Figure since it now has a sports car motor in it, it should be treated like one.

I never noticed any difference in performance by using synthetics although I'm sure there could be. I just switched to synthetics on my Fleetwood and plan on changing the oil after 5k miles worth of use vs. the standard 3k. Figure since it now has a sports car motor in it, it should be treated like one.

That's the plan I was just thinking about. If I were still using all conventional oil, I'd stick to 3k; but if going synthetic, 5k would be more reasonable.

That's the plan I was just thinking about. If I were still using all conventional oil, I'd stick to 3k; but if going synthetic, 5k would be more reasonable.

For me, changing oil is the cheapest insurance for maintaining an engine and giving it a longer life. Irv Gordon and his Volvo 1600P made it to 2,300,000 miles!!! 2 Million plus?! So why take chances? In the long term I'm sure you'll save on fuel economy and mechanical work. That is, if you plan on driving the car long and maintaining it new.

As for the debate between Synthetic vs Dino oil, whatever you choose, Irv Gordon suggests using a certain oil and sticking not only to the type, but the brand as well.

It may have been sheer coincidence, but I think I picked up a little horsepower and about 4 mpg on the highway by swtiching to synthetic. Didnt change around town mileage though.