gyates93

I've just recently switched my truck to 5W50 synthetic after exhausting a 48L supply of free Castrol GTX and I have to say I'm impressed. The truck has 375K km on it and valve noise has noticeably reduced and the truck has more oil pressure. I was worried about oil leaks after switching to synthetic but so far so good, knock on wood. My truck does consume a little oil when running at high RP
​​​​RPM, I am hoping for an improvement here as well.

Does anybody have any thoughts about this switch? I know this is a little thick compared to the manufacturer's suggestion for the 3.0 but the truck is still starting nicely and it is VERY cold here in NS so I'm pretty confident.

millball

In your cold climate, and with your high mileage engine; looks like you have a winner.

ev13wt

Not sure 50 weight is a good idea. It is so thick at operating temp, might be too thick for some oil passages. The higher oil pressure is an indicator for this.
I would put 5 or 10w40 max in a high milage.

GO_BLUE!

I have a couple quarts of Amsoil 5W-50 weight oil that added to my 3.0 3VZE with 158K miles. (~4.6 quarts, oil capacity). I filled the rest with Amsoil 0W-30. Both oils are 100% synthetic and the first thing I noticed is the higher oil pressure and quieter engine. That said, gas mileage is down a bit and I'm not sure my truck warrants such a thick oil. Maybe in summer, but definitely not winter. And I live in San Jose, CA where it never gets below freezing. And the 5W-50 is $14 bucks a quart which is roughly the same price as a gallon of Shell Rotella T6 5W-40.

I think 5W-40 is probably the heaviest oil I'll run (in the future) but since my engine really isn't "worn" yet. The 0W-30 is where it seems to be happiest. If I had more miles like you do then I'd consider 5W-50 but that oil is quite thick and probably shouldn't be used for small trips... low mileage travel that I do around town. The good news is that the Amsoil lasts 10K - 12K miles or even more, which is a year's worth of driving for me. And I have about 3/4ths a quart of 5W-50 left over, so if I head to the desert or death valley or Arizona, then I can use it to top-off whenever I get a little low.

The bottom line here is - - 5W-50 probably isn't worth it, in terms of cost and value. These engines don't have a turbo and spec is (I think) 5W-30. Shell Rotella t6 5W-40 diesel oil is perfect for the summer (for me.) especially on long trips. But if you have a higher-mileage engine and you don't care about the price, then run 5W-50 and be prepared to listen & watch carefully for the effects such as lower gas mileage. Do you really need a thick oil churning around in there? If you're on the highway or in the desert Southwest a lot, the 5W-50 makes a lot of sense. Especially for long trips. Use a quality oil filter (Amsoil, Royal Purple, etc) and you can get 10K-15K miles out of a quality 5W-50 synthetic oil.

I'd love to hear more experiences with 5W-50.

https://www.bobistheoilguy.com/forum...Number=1265934