What weight oil for two Ford engines?

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Jun 2, 2009
Two vehicles:

2014 Ford Edge, about 42k on the clock, 3.5L NA engine (no turbo, no DI). Runs fine, has been getting a diet of 5W-20 its whole life with 7500 mile OCI. I use either Mobil 1 or QSUD. Mostly highway driving for its life, and especially now (wife has a 35 mile daily commute, one way).

2018 Ford F-150 5.0 Coyote V8. Starting this year, this engine is dual injeted so it will probably get a little fuel dilution. 2500 miles on the clock, getting factory fill changed at dealer next week (for free, which is why I'm doing it) where they will likely use 5W-20 Motorcraft blend. Will run that to 7500 miles (so a 5000 mile OCI). I will change 5000-6000 mile OCI after (twice per year) with Mobil 1 or QSUD. Mostly city driving with 10-15 trips to northern WI (2 hour drive one way) per year. I also have a fiberglass 16 foot boat that weighs about 2500 pounds that I tow in the summer, but don't go very far with it.

My goal: best engine protection, want both of these vehicles to last a long time. I'd also prefer, though it isn't a huge deal, to use the same weight oil for both vehicles.

I'm wondering if it would be better to switch to 5W-30? I don't want the oil to be sheared down too much by the end of the OCI and the 30 weight leaves a lot more room.

I'm more concerned about the F-150 because of fuel dilution. Also, the upgraded 5.0 for this year increases the sump to 8.8 quarts from the previous 7.7 quarts. That move makes it seem they are worried about heat, even though there is an oil cooler on the engine. From what I have found, tolerances haven't really changed for 50 years so that isn't a good reason for thinner oil. The main reason I've seen to stick with the thinner oil is due to cam timing. Not sure if there is any truth to this?

I've seen a lot of people on the F-150 forum who have switched their 5.0 Coyote (before it was dual injected) to 5W-30 or even 5W-40. There seems to be a lot of people who think that the lighter oil is only recommended for CAFE. As evidence they point to the 6.2L recommendation being changed to 5W-30, when it had been 5W-20 (that engine is now only in the Superduty, not the F-150, so it it exempt now from CAFE). Also they cite some of Ford's engines (and other company's) recommending heavier oil in other countries that don't have CAFE, for the exact same engine. The 3.5L Ecoboost used to recommend 5W-20 until Ford apparently found that wasn't enough protection and now recommend 5W-30. There are also a few quotes mentioned which are supposedly from former Ford engineers that say 5W-30 is better for engine protection.

I have a pretty big stash of 5W-20 that I could return or exchange for 5W-30.

Even the Edge is in manufacturer powertrain warranty for another two years or 18k miles.

I'm wondering if it would be smart to get an oil sample analysis done on both at the end of the next OCI to see shearing and (in the truck) fuel dilution? Then go from there.

I would think that at current OCI on both vehicles running the same weight oil as now would work well and last a long time, as in past 300k miles easy. Why bother to change.

An oil analysis never hurts if you want to spend the extra money to see how things are running inside the engine.
Using a name brand 5w20 oil as recommended in both engines changed at regular intervals will serve both engines for a long time.

The driving on the edge sounds super easy on engine oil.

The truck should have an oil life monitor and it will suggest a lot longer than 5000 miles. My 2016 F150 with the 2.7 comes out with an interval that ranges right around 10,000 miles nearly every time. I change at 7500-8000 miles.

The increase in sump size is likely due to the change to direct injection (and one port injector) and fuel dilution and not heat generation. The 16 foot boat is a toy to your F150. I tow a nearly 5000 lb boat to Canada with the little 2.7 and its like it isn't even back there...

A lot of people use a 30 weight or a 40 weight because is whatever they used in their older other vehicles. I remember when people complained 5w30 was too thin yet I ran in every car I owned that called for it to no issues. In the meantime, I've run multiple modular motors out to nearly 200,000 miles before selling them with no motor issues period on 5w20 (except for a 3V 5.4, but that was bad timing chain design and seals and using a heavier oil more or less just masked the sounds of the issues...)

Don't overthink it and enjoy...
FWIW the 5.0 Coyote in my Mustang calls for 5W50 because it is a Track Pack car. That being said, if I were you, I would run a synthetic 5W20 in whatever brand had the combination of warm fuzzy feeling and availability and change it at whatever interval makes you feel the best while the vehicles are still under warranty.
Buy whatever is spec'd for the F150, keep the receipts for warranty and run it in the Edge. I assume the warranty on that is going to be up soon.

Run 5W30 in the F150 and go from there. You could also run 10W30 to be one of the cool kids on BITOG but IDK if I would do that in Wisconsin.
My dad had a 2011 F-150 with the 5.0. He used Mag 1 synthetic 5w-20 or 0w-20. Changed when the oil life monitor said too. Just traded it in at 120k, but still ran like the day he bought it.

Like previously stated Ford uses up to 5w-50 in the 5.0. so it seems tolerant of a wide viscosity range. If you were worried you could do a uoa to get a fuel dilution %. However, as shown in several Ecoboost UOAs fuel dilution does not directly correlate to increased wear at oil change intervals recommended by Ford.
Run the factory weight and do a UOA to see how things look. Fuel dilution is a condition on the EB motor, not the 5.0. And even with fuel dilution, there are no UOA’s here that show any wear problems.

I think the internet is really gotten itself spun up on fixing a perceived issue, not a real problem. For example, go find yourself a Ford manual for the first year the EB motor was offered. It calls for 5W-30. I too believed what I read here and on other forums until someone pointed out the manual calls out 5W-20 for the motors other than the EB and 5W-30 for the EB.
Ford is now finally recommending 0w-20 if you are in a colder climate. I’ll be using this in my 2018 5.0 supercrew lariat 502a with 3.73 gears. But I’m in Canada. And we get a pretty cold winter so I would benefit from it. Will be running it year round and following the oil life monitor for the intervals.

Still waiting to see some uoa’s for these new engines. I don’t think there will be much of any fuel dilution. The new dual fuel ecoboost has very little. The 5.0 should have much less then that engine.
For “best” protection the 5w-30 is what I would run. However unless you plan on doing a lot of hauling or put a bunch of weight in the bed of the F150 I don’t think you will see a benefit. The oil cooler should do its job and keep the 5w-20 in grade when you’re working the engine hard.
Use the 5W-20 and you will be fine. I run Motorcraft 5W-20 in my 14 Mustang GT and it runs fine. My fiance' bought a new F150 with the 5.0 last year and she plans on running the 5W-20 as well. Her son has a 2014 F150 with the 5.0 and he runs 5W-20 Motorcraft in it and has since new and he has almost 130,000 miles with no issues.

I think people overthink this viscosity thing.
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