I'm wondering what weight oil to use in my 2V 5.4 on its upcoming oil change. Last time I used Mobil 1 5w20. I will continue to use Mobil 1, but wonder if 5w20 or 5w30 would best suit my needs? What is the difference between the two. Advantages? Disadvantages? I'm looking to have the truck run as smooth as possible. On cold starts, the engine sometimes makes a noticeable (only to me) ticking noise, and once warmed up, I (again, no one else) can pinpoint a slight noise that sounds like a mild piston slap at idle.

I'm not trying to open a can of worms about what oil is best, I just wonder what is best for my application.

Simply put, which weight will make my engine quietest?

 

meant to put this in the engines forum...

 

Whenever I switched to Mobil 1 synthetic at 14,000 miles - I went to the 5w-30, I don't know much about oil all I know is I asked at the local Xpress Lube and they said that I would lose .6 mpgs. I don't feel like I've lost much of anything, and the engine warms up A LOT faster. Also much quieter on start-up, no ticking or any other weird engine noise. Supposed to last longer too, the oil change place still recommend every 3000 though

 

Ford recommended 5W30 for early 5.4 2V's, then switched to 5W20 for the later years. Both weights will be fine, although 20 weight oil is light for Texas weather. As for your cold weather noise, both weights are the same at 5W and are not likely to remedy the problem.