Synthetic Oil

Is it never to late to go synthetic? Are there any benifits to using it?

That is a broad question.
Synthetic will not restore a worn out or high mileage engine.

If you are going to use it switch it over when the engine is low mileage.

It last longer and gives a lot better lubercation in cold and extream hot conditons.
But does cost more but balances out with longer lasting oil changes and less engine wear.
But remember it gets dirty just like regular oil.
So keep a good oil filter and good filter changes with it.

My truck has 70,000 on it and run very good .It uses no oil. Would I benifit by changing to synthetic or would that screw up the whole thing.

Use the synthetic. You will get better gas milage.

OK what brand and weight? I heard Amsoil was good. I have the 4.8L

I use Amsoil in everything I own. In my truck which has the 5.3 I use 5w30 all year round. The filter and oil change requirements are: Oil every 12 months or 25,000 miles(whichever comes first) and the filter every 6 months or 12,500 miles. Go to their website www.amsoil.com (http://www.amsoil.com) and check it out. I have never had any problems with their products.

Amsoil was one of the first to come out with synthetic oil.
And is still one of the best.
Mobile one is another top one.
But there has been a lot of changes made for newer engine requirements.
MT

OK, Amsoil 5-30 is what I'm going to use.

But remember it gets dirty just like regular oil.
So keep a good oil filter and good filter changes with it.
That is good advice. I use A C Delco filters and change just the filter half way through the time I have the oil in my engine.For example, I leave my synthetic oil in my engine between 10,000 to 12,000 miles. I'll change just the filter between 5,000 to 6,000 miles and top off the oil to make sure it is the proper level on the dipstick.

Keep in mind synthetic stays much thinner and can accelerate any oil leakage you may have. At 70k miles you should be ok but I wouldn't start using it in a vehicle with over 100k or that has any leaks already. I made this mistake in a Subaru Legacy I bought with 108k miles. I started using synthetic and by 130k miles I had replaced more seals and gaskets than I could count. The synthetic found every tiny hole that the regular oil had gummed up and cleaned them right out.

Keep in mind that using any dino commercial hd type oil such as shell rotella t, chevron delio, or esso xd-3, will also cause leaks and issues in high mileage engines as they are also very high detergent oils. It's not only the synthetics you have to look out for.

AS stated by others use the Amsoil 5w-30. However I would recommend using their engine flush prior to the installation of the new oil. This will clean the engine first. I recommend this oil exclusively, it is truely the best out there.
For more info see www.synthetic-lubricants.com or Amsoil.com

Keep in mind that using any dino commercial hd type oil such as shell rotella t, chevron delio, or esso xd-3, will also cause leaks and issues in high mileage engines as they are also very high detergent oils. It's not only the synthetics you have to look out for.

I'm running Rotella-T in my '88 350 - which has 282k miles on it, no leaks.

Keep in mind that using any dino commercial hd type oil such as shell rotella t, chevron delio, or esso xd-3, will also cause leaks and issues in high mileage engines as they are also very high detergent oils. It's not only the synthetics you have to look out for.

It's not so much the detergents as the fact that synthetic doesn't burn and thicken on the outside of a motor like dino oil so it won't plug it's own leaks. Also in the cold when all the metal shrinks the synthetic stays thin and can flow out any tiny gaps. I'm not knocking synthetic by any means. If I bought my truck with lower mileage I would definitely use it. My last 3 cars saw nothing but synthetic. In my truck I use regular oil and Lucas oil stabilizer and it seems to like it and run pretty quiet.
I've seen many old cars that didn't leak until someone cleaned the gunk from the motor that was clogging the little holes. Synthetic effectively flushes out the holes.

They say any regular oil of a brand name is probably made by the same company with a different label and is equal in performance. Is this true with synthetic?

different companys add small amounts of different "stuff" in there products, I always run 5w30 mobile 1 synthetic, and some lucas, which makes a noticable difference in engine noise.I change my oil every 3000 miles, and always change the filter with the oil. Not a problem with new silverado @ 52k, and not a prob with 88' 305 w/ 250k, sold it running strong

Check out "bobistheoilguy.com" forums and you will find more than you ever wanted to know about oil.