Thread: Effects of Synthetic Fluids on my S/C GTP

While various manufacturers of synthetic lubricants have done dyno test and have shown about 3 - 7 hp gains (depending on engine) from switching to synthetics, I would not switch over to a synthetic motor oil solely on that premise.

To answer your question about seals and gaskets, no, there are none in modern engines that are incompatible. I think you'd have to go back to the early 70's or so before you'd find any engines that had those kinds of issues and thats assuming they are still running OEM gaskets and seals.

You'll hear reports also that switching from conventional to synthetic and not being able to switch back and vice versa, and those are all nonsense. You can switch back and forth to your hearts content.

Hopefully that info will help you out some.

I run royal purple in mine but it expensive as hell, but supposed to be one of the best. The thing I dont like about it is the only way you can tell it is starting to wear and burn up is buy smelling it because it is purplish black to begin with. I'll probably just go back to Mobile! synthetic due to the cost.

Originally Posted by Uno99

I run royal purple in mine but it expensive as hell, but supposed to be one of the best. The thing I dont like about it is the only way you can tell it is starting to wear and burn up is buy smelling it because it is purplish black to begin with. I'll probably just go back to Mobile! synthetic due to the cost.

Lol, smell and color have nothing to do with an oil's health anyway. The only way to really tell is to have it analyzed. If an oil is dark, that's good since it's picking up and suspending carbon that would otherwise turn to sludge. Cracks me up when people say "my oil turns dark fast, so I have to change it often".

Originally Posted by Jess3103

IMO I used royal purple in my 05 GTP. I had ALOT more done to that car and LOVED the royal purple. When I got the 07 I changed all fluid and added Royal purple. I went to have my oil changed before a road trip and it was about 500miles away from being 3,000 and the Tech guy asked when is the last time I changed my oil!! He said it looked as if I hadn't changed my oil in a good 6K miles! So im not sure if I got some bad oil or what. But I went back to Mobile 1 Syn. I know he was not bs'in me because he is my uncle! LOL.

The key word in that sentence is "looked". Royal Purple isn't a conventional oil and you can't treat it like one. You can't look at the oil to see if it needs changed. The best way to know if a synthetic oil needs changed is to have it analyzed. Or just change it at regular intervals. But synthetic oils can go much longer oil change intervals than 3000 miles. So first, there was no reason your oil needed changed when you changed it. Second, you can't just look at a synthetic oil to see if it needs changed.

Originally Posted by Zef_66

Second, you can't just look at a synthetic oil to see if it needs changed.

You can't do that with any motor oil.

If its milky, thats coolant in the oil.

If its thin (and thats a very subjective measurement) you probably has some amount of fuel dilution, but in most cases if you can tell its effect on the oil visually then its WAY past the danger point.

Lastly, different motor oils react differently from engine to engine, even engines of the same type, configuration and so on. You could take L67 engine #100 and L67 engine #101 directly off the assembly line and put the same identical oil in them and drive the cars in identical fashions and in identical conditions and they will wear and react in completely different ways. The only real way to tell how well or how bad a motor oil is holding up in an engine is with oil analysis. Anything other than that is speculation at best.

^^^^ word