My Ram has 21000,miles on it . Just started doing the famous hemi- tick only on cold start up. Have taken it to the dealer for all my oil changes. They don't use synthetic ,just the standard oil. Should I change to full synthetic now? It says in my owners manual standard oil is recommended / synthetic is fine as long as same viscosity.
There is a 35,000+thread on this, with tons of testing and analysis all paid for by individuals.
Cliff notes is this:
5W-20 isn’t enough, run 5W-30 or higher.
Dino Oil—Pennzoil Yellow Bottle in 5W-30
Synthetic Oil:
Redline 5W-30
Amsoil SS 5W-30
Quaker State Ultra Durability 5W-30
Pennzoil Ultra Platinum 5W-30
Run 7.5-8qts as 7qts Isn’t quite enough for the pickup in the oil pan.
Oil filters matter, more than we thought.
Best filters:
Royal Purple
Fram Ultra Synthetic
Amsoil
2018 Ram 2500 6.4L 4x4
Amsoil SS 0W-40