So what's everyone's opinion on royal purple motor oil and using it in the 5.4's? I know it's extremely high for oil, so I won't say is it worth what it cost because I know there are very good oil brands for a lot less... So I'll ask, Is it a good choice to put in the truck as opposed to say, mobile 1 full synth.?? I've seen a few test for it on tv and they do a good job at makin it look superior to others but then again that's "tv" for ya! So let's hear some thoughts on this subject, and people experience with it.

And yes I searched for it!!

 

I generally run mobile 1 with a k&n filter when I do my own oil. I go with 10w-30 instead of the 5w-20 since that is what mobile 1 recommends for truck engines. I've heard good things about RP but never had the money to spend on it.

 

In my '95 302 I ran Castrol GTX High Mileage 10W-30 because it had way over 75K miles. After hearing all the cam phaser horror stories of the 5.4L's in the '04-'08 models, I'll only run 5W-20 in my 2006 5.4L. I run Mobil 1 Full Synthetic 5W-20 with a motorcraft filter. Reason being, Ford engineers designed and tested these engines with a 5W-20 synthetic oil and motorcraft filter, so there must have been a good reason they recommended them! Stick with what the engineers recommend lol

 

I also run mobile 1 fully synthetic in my 5.4. I ran it in my new motor I put in my ranger and never had a problem with it so when I bought my 04 f150 3 months ago with only 30,xxx miles on it I changed the oil and went with mobile 1. But I've always wanted to try RP because on all the tv shows like horsepower tv, or muscle car tv and others alike they all run RP oil so obviously it's some pretty good chit? And I always want the best for my vehicles so I've been considering RP oil and wanna hear everyone thoughts or experience with it?

 

I am also considering Royal Purple for engine, transmission, and gear oil.. It has great reviews...

 

Last year I purchased a case of 5W-20 RP Full Synthetic and when I ran it last winter on a cold start up, the engine wasn't any slower sounding at turning over. It may as well have been warm!

Due to cost of RP I just switched to 5W-20 Mobil 1 Full Synthetic and now it's winter and suddenly my truck is a lot slower when turning over at a cold start.

I wish I had stayed with RP because the slower start annoys me. I know it's to be expected, just the sound annoys me.

IDK if it is actually the difference between full synthetic Mobil 1 and RP, it could be my battery I suppose, but really any Full Synthetic will be better then a blend or non synth. so just get whatever you can afford and still be happy with!

 

Yep.. More great reviews... Can't wait till it's time to add mine... Did you run it in your transmission and hubs also?

 

I ran RP in my Mustang. Ran it for 7k miles and it looked brand new.

Now I just run regular Motorcraft but I'll probably switch to 10w-40 on my next oil change.

 

When it comes to keeping my engine goin trouble free I will pay for the high priced stuff. As long as it's worth it and it is as good as they make it look? I'm sure it applies to oil as it does anything else in life "u get what u pay for" so I'm thinking about switching from mobile 1 full-syn to RP full-syn. I just want to hear people's experiences with it and if they think it's worth it and could possibly keep these shoty cam phazers from giving me problems by running a good oil like RP?

 

I have it in my axles, but not my transmission. I bought my truck used and couldn't find any records of transmission flushes done to maintenance specs. So I have decided to wait until I need a new tranny and then start on a schedule rather than spend several hundred dollars on RP ATF and risk my tranny kicking the bucket cuz of the oil change.