I want to use synthetic oil for my engine, trans, and rear end. I have 90,000 miles on my 94 T/A. What weight should I use with that many miles. I was told that when you use synthetic oil, that you change your oil every 10,000 miles. Is that TRUE??? I also read an artical that says that the full royal purple drive train kit would raise you a couple horses. It's hard to believe that all that can come from oil. How much would it cost me to change my drive train over to synthetic?

 

first of all..........no matter what oil you have...........change it every 3000 or every 3 months.

your oil might be good for longer, but why even bother pushing it with something you cant prove? (ive read all sorts of articles supporting all sorts of opinions.....its tough to know whats marketing bs and what isnt..........you can make a study say anything you want)

the way i look at it........its cheap, it only takes 30 mins, and it will keep your motor healthy............just do it.


i just recently switched to royal purple for my engine, seemed the idle was slightly quieter afterwards.........seems to be good stuff. ($4.99ish per quart).


as for gaining horsepower........maybe if you changed motor oil, tranny fuild, and rear differential fluid all at once...............the combined reduction of friction might be worth 2-3hp or something, but nothing you would notice, thats just marketing hype.

 

Amsoil gets my vote for sure. check them out at. www.amsoil.com

 

Changing a synthetic oil every 3k is simply a total waste of time and money, you're not making your engine last any longer by doing this, people have proven time and again that you can go with longer intervals and get long engine life.

And here is a study which helps to show how long oil can last:

http://neptune.spacebears.com/cars/s.../oil-life.html

If you run synthetic and go with 5-6k intervals, I guarantee you that your engine will not die of an oil related failure before it hits 200k.

 

I have people come in my shop all the time and say "XYZ oil is the best" I ask them "How do you know?" They can't answer that question. I say have you ever seen an oil related failure? I never have since 1975. I use synthetic to prolong oil change intervals. Synthetics can stand up to higher temperatures before breaking down.

I sell Amsoil and I'll tell you that all synthetics are good. If you change oil often (like every 3k miles) any oil is ok.

If you race use a sythetic.

 

like i said........it might be able to last 20k for all i know

but i dont care..............changing oil is easy, cheap, and keeps your motor fresh. theres no reason NOT to do it, unless youre broke and lazy.

btw, ever seen pics of the inside of an engine from someone who does 5000mile drain intervals? ive seen some completely sludged up, and some still pretty clean, both with synthetic. so it can go either way.
id rather not take the chance of my engine getting dirty like that when its so easy to change.

 

Yes I have seen pics of the insides of an engine with people doing long drain intervals, and they look just fine. The 3000 mile oil change is a thing of the past, it's exactly what the oil companies and fast lube places dupe you into believing is the only way to go, even with synthetics. If you want to continue this wasteful practice it's your decision, but you aren't making your engine last any longer than the guy changing his oil every 5 or 6k. Oil analysis results have proven time and time again that the wear on your engine doesn't automatically increase when the oil has 3k on it.

It's not a matter of being broke, or being lazy at all. Even if I was a millionaire I wouldn't change my oil every 3k.

 

I am using RoyalPurple also, I change my Oil every 5000 miles, No engine problems at all. Put headers on the t/a and dynoed 312 hp 346tq Been using mobile one also, so basically there is no fear of leaving it over 3000 miles, just check it and keep it maintained.

Now for our brake fluid and rear end it is good to use red line oils will keep car very strong. brake fluid also.

 

If you want to change your oil every 6000 miles, thats up to you. There is other reasons for keeping fresh oil in your car every 3000 miles. What about condensation? I don't car what your running, water is not good. Why take the chance on such an expensive investment. Maybe the oil would last. I know that I would'nt keep it in my engine that long. I call it insuranse. It all depends on your driving habits and the car. I'm running a 12# blower which makes alot of heat. That in turn will break down the oil quicker. All I'm saying is, who wants to take the chance?

 

If i change my oil every 3k miles, and race ...do i still need synthetic, or is non synthetic fine?

 

Maybe I should give a little bit more details. I like to do oil analysis when I change my oil (and sometimes in between changes too) and I've never seen water in my oil. That's because any condensation that gets in there will get burned off as soon as the car is driven a few miles. So there are no worries there.

The only time I see a problem with extending my oil changes is in the wintertime, when I see a little bit more fuel in the oil, but that's only when it's extremely cold like this winter was.

I strongly urge you guys to do oil analysis yourselves, that is the best way to determine your own oil intervals for your driving conditions. Then you'd quickly see that 3k is too soon and unneccessary.