Ive heard all the good things about switichin to Royal purple synthetic oil, but i have also heard alot fo rumors..... Is it actually BAD to switch to royal purple systhetic motor oil after running regular oil through her for 50,000 miles?

i know that stuff is expensive but from what i read it has amazing benefits..... much cleaner, more power (5-8 hp? thats crazy), llonger change intervals (id still change every 3,000) and even cooler running temps

 

I've never heard of anything regarding it...

 

If I understand your question right, it's not specific to Royal Purple, but switching from mineral to synthetic has "caused" problems for "some" in the past.

As far as Royal Purple, I've heard good and bad as I've considered adding that to my Stang also. I've heard that the oil itself can break down after a certain amount of heavy use. Those aren't my words/thoughts, but what I have heard from others.

Of course Horsepower TV replaced the oil, transmission, and gear fluid and gained like 8-10 hp.

Let's see what everyone else has to say.

 

I think any hp gains you would get would be minimal. I run mobil1 synthetic in my engine, but I run amsoil synthetic in the tranny and rear end. I dont think they help anymore than another brand, or even that much over a mineral based oil, but i can go longer between changes, which is a plus for me.

The reason i havent tried RP or Amsoil in teh engine is just because of the price, availability and how much i have to change my oil.

 

I've been told by a few mechanics that Royal Purple is the only oil dyno proven to add a couple horsepower, but that was probably only in race engines and I never actually saw a dyno report. I use either Castrol Syntec or Mobil 1 in my 109,xxx mile fox and it had conventional mineral oil in it till 97,000 miles. When I switched I never noticed any problems or leaks.

A recent MM&FF magazine had a reader letter response that said people may think synthetic causes leaks because it will actually uncover engine problems that a marketing gimmick like "high mileage" oil would conceal, such as a leaking piston ring that was not detected before because of the "conditioners" in the high mileage formula....alright I'm done.

 

i use MOBIL 1 10/30 in my 92(103K) and Castrol 5/20 in my 04(19k)didnt really notice and performance gains. just switched b/c i dont dog my cars, but i do like spirited driving and synthetic doesnt breakdown as much w. mileage. i only change the oil in my 92 2 times a year(i only put 8k on it)and thats just b.c i want fresh oil for the winter. i change the oil in the 04 every 5k. i know it can go longer and the oil looks brand new when it comes out. but i get them done for like 20 bucks for full synthetic

 

I never noticed a performance increase when I switched oils either and I never expected any. I change my synthetic every 4k and its fairly black by then (i'm running 5w30 right now for winter)