Oil Recommendation

[69mach1]

My mechanic suggested I use a heavier weight oil for my 150,000 mile EB.

I like using the once a year oil.

Any recommendations?

Thanks

 

[JasonH]

What is this once-a-year witches brew you speak of? No mention as to annual mileage, engine condition, etc? Any good synthetic in Ford's recommended viscosity and rating should work. For example, Ecoboost wants WSS-M2C946-B1. Not sure what the 5.4 calls for. Your driving habits will have the biggest impact on the oil durability. Frequent highway commute > Short trips in the cold. Some people go thicker if they have a leak. You can also get a used oil analysis from a testing lab, such as Blackstone Labs. Some 5.4 oil discussion links are below.

https://bobistheoilguy.com/forums/threads/5w20-vs-10w30-pennzoil-up-in-ford-5-4l.273894/

https://bobistheoilguy.com/forums/threads/5-4-3v-new-motor-5w30-or-0w40.313756/

https://bobistheoilguy.com/forums/threads/5w20-or-5w30-in-5-4l-ford-3v.320531/

 

[whtbronco]

In my '04 EB 5.4L I used Amsoil 5w-30 Signature Series at first until depleted and then switched to 5w-20. I have changed the oil once a year since new. Currently have 261k miles, have not yet opened the engine, oh crap I just jinxed myself. Here's our other currently owned vehicles with the same oil change interval.

2002 Monte Carlo 11k miles, bought with 5,900 miles in 2019
2003 Monte Carlo 187k, bought new
2000 Ranger 181k miles, bought with 132k miles in 2012. PO reportedly used Mobil 1 since new.
2014 Focus ST(son in laws) driven stupid hard and pushing ~350hp ~140k miles

I switched to Amsoil lubricants ~30yrs ago and have done yearly oil changes on every thing since. Does it work and is it safe, seems to me it is with a quality oil and filter at least. Amsoil recommends 25k miles or 1yr whichever comes first. I change t-case and diffs every 2yrs, trans pan every 2yrs, brake fluid yearly, coolant 3-4yrs.

I have tried many times to disprove Amsoil's claims and failed every time. I gave up trying.