Hi All,

I was going to change the engine and rear diff oil on my 2018 2.7 ecoboost. For the engine, I was going to use 05-30 full synthetic (either mobile 1 or valvoline). Is that an appropriate selection?

For the rear diff (9.75 gears, locking rear diff, and 3.73 ratio), I was going to do Lucas oil 75w-90 or 75w-140 full synthetic. Are either of those appropriate?

The truck is just daily driven at this point.

Edit: these engines oils are my personal choice:o https://mobiloil.com/en/motor-oils/m...ual-protectiono https://mobiloil.com/en/motor-oils/m...e-high-mileageo https://mobiloil.com/en/motor-oils/m...e-high-mileage These oils state that they meet or exceed the certification listed in my 2018 owners manual for the 2.7 ecoboost.

-kehyler

 

You have not consulted your owners manual have you? Because if you had you would be posing different questions as it is all fully detailed.

 

A diff fluid change on a truck that's not even a year old yet? Is this a joke...where is the hidden camera?

 

Unless you've driven through 1 foot or more of standing water, with the chance that the vent took in some water, you don't need to change your rear differential fluid for a long, long time. Check your manual for the required lube viscosity.

 

Pennsoil Ultra 5w30 oil. Because Noack

Motorcraft diff oil that is suggested in the manual. No reason to change the diff oil already unless you have water in the oil or you tow heavy and often at high speeds.

 

If you are doing engine oil and differential oil fluid changes way way way way early, do the transmission and coolant ones too. Don't forget to swap out the windshield washer fluid for fresh one too.
Or you can just use the oil life monitor to do the engine oil change when it becomes necessary and do the worry less, drive more thing. Really, the owners manual does show recommended service intervals and activities to be performed - it works well for your daily driving usage.
Worry less, drive more.

 

Sorry, I wasn't asking about wether or not it was reasonable to change early, nor was I asking about what's listed in the owners manual (both of which I already knew). I was trying to ask if my two selections were good.

 

"Good" meaning what? The diff oil doesn't even match the owner's manual spec., does it? Kind of an odd question, for a brand new truck. I put all kinds of fluids in my old Pathfinder after it hit 150,000 miles. Not when it was new though.

Found an owner's manual online. Pretty nice. Page 419. Says 75W-85 synthetic is recommended for the front and rear axles. Good luck.

http://www.fordservicecontent.com/Fo...US_05_2017.pdf

 

Q1: No
Q2: No

 

The diff oil of 75W-90 was because I didn't know they made 75W-85 Synthetic. Maybe one of the major brands makes it and I don't know. I'll look.