is it bad going fro regular oil to full synthic back to regular then back to synthic

previous owner used regular oil then went to Pennzoil synthetic then back to regular would it be bad if i started to go full synthetic after this next oil change?

 

No it wouldn't be bad. Full synthetic is the way to go imho.

And as far as the switching itself there should be no problems. You have a fairly recent year truck (I'm assuming 05-15) which has a modern engine designed for the possibility of being run with synthetic oil.

No problems.

 

It's not hurting anything. You can mix them if you want.

 

No issues, use whichever you like, Dino or Synthetic.

 

yeah 2007 with 67k miles 4.0 v6

 

Most synthetic blend oils are full Dino and synthetic so you have your answer use either one
TOM B

 

X2

 

How would synthetic oil hurt an older engine (say from the 70's or so)?