Which Oil to Use?
 

I just got my 2006 Ranger, it has 104000 miles on it. I haven't changed the oil or filter yet. I don't know what kind of oil the previous owner used. Would there be any problem putting synthetic oil in it?

Ive heard you shouldnt but i see people doing it. I just switch to synthetic after i did my heads. I say go for it. motorcraft filter and some 5w30 (depending on your season).
also dont use valvoline unless you want to stay committed to it, it coats the valve train for protection and i guess if you switch around alot it can add gunk and grime. dont quote me on that though

There is no problem switching to synthetic... just stick with the grade it says on the cap.

mobil 1 synthetic ftw

Agreed.

X2 on Mobil.

I run Motorcraft 5w-20 synthetic blend from Wally world, made the switch from conventional to synthetic (blend) at about 145k miles. The engine is noticeably quieter at an idle with the MC blend in it. Great oil at a great price.

x2. i used to run the same oil, bought from the same store, with a FL400S motorcraft filter

I get Mobil one discount slips at work so I got 10 5qrt jugs for $20 tell me that's a good deal. Now each jug u get a free Bosch filter so Bosch makes an outstanding product and the Mobil 1 filter so I got 10 of them. I'm set for the next 50k miles!

why 5w30 instead of 10w30? sorry ive been a powerstroke man for years and just bought a ranger so im getting re familiarized with gas engines and rangers

original recommendation from ford was 5w30. the 3.0 has been back-spec'd to 5w20 if you want. I tried it for a while and saw no noticeable fuel gain...so I went back to 5w30. if you are in warm climate, you'd have no problem with 10w30.

I used m1 5-20 since new, as the milage racked up tried motorcraft a few times, i now use rp 10-30 with the wix filter. The engine does sound quieter, as for better fuel milageits hard to say but ive always averaged 19-21 mostly highway, i have to change the heads since my symptoms r the same as bad valve seats. I will say i have always ran93 octane, tried 87 power and milage dropped, but my engine did not ping.

Im not in a warm climate in fact its snowing right now... but thank you i will use the 5w30 thats what the previous owner ran in it as well.