Which Oil Weight?

[starcrwzr]

Ok, it was time to change the oil in my 2016 Sunstar LX (Ford V10), first time for me since I owned it. So I looked up the recommended oils in the Ford Manual and they the top four listed say 5W-20W. So that's what I bought, Castrol GTX 5W-20 Full Synthetic. After draining the old oil, and getting ready to pour in the new, I see on the oil fill cap that it says 5W-30W! What's going on? Should I drain the new oil I just put in and put in the 5W-30W? I live in the mountains east of San Diego and we do get some snow up here but most of our trips are during non winter months. Just getting ready for a trip from Home to Flagstaff for a week or two and wondering if I've made a mistake.

[starcrwzr]

Looking back at the manual, there's a little tiny footnote number above the part number. Going to the next page, down at the bottom, it says "1Reference the reservoir cap for proper fluid." Wish I'd seen that before I bought the oil.

[vito.a]

I really don't think it's that big of a mistake. If your engine was 2 years newer it might even specify 5W-20.
As the EPA standards get tougher and CAFE (corporate average fuel economy) kicks in manufacturers are specifying lighter weight oils with little to no change in the engine.
On top of this you used full synthetic which is definetly better than 5W-30 non-synthetic.
I would run the oil and not worry about it. Just go back to 5W-30 at the next change interval.

[grindstone01]

I disagree, 30w oil is a thicker than 20w oil and if the engine tolerances are designed for 30w oil then that is what should be used. You do not want to run a lower viscosity (thinner) oil at engine operating temperature.



(copied from Google)


The 40 in a 10w-40 simply means that the oil must fall within certain viscosity limits at 100°C. This is a fixed limit and all oils that end in 40 must achieve these limits. Once again the lower the number, the thinner the oil: a 30 oil is thinner than a 40 oil at 100°C etc.

[Mudfrog]

Most owner's manuals list different viscosities that are ok to be used in the engine, usually based on what the expected outside temperatures will be during the oil's use. From just looking online, it appears your manual doesn't show temperature ranges.

The 5W-20 is one of the recommendations, actually the first one listed, so i'd say it was fine.

Edited to add: Well shoot, went back and read again. I see the footnote in the manual now. I'm kinda thinking it'd bug me too much to let go so I'd probably go ahead and replace with the 5W-30

[grindstone01]

Originally Posted by Mudfrog

Most owner's manuals list different viscosities that are ok to be used in the engine, usually based on what the expected outside temperatures will be during the oil's use. From just looking online,it appears your manual doesn't show temperature ranges. The 5W-20 is one of the recommendations, actually the first one listed, so i'd say it was fine.

That may be true for the first number which is the viscosity at cold start up temp and is usually a short time period. The second number is the viscosity at 100c or operating temperature which is usually the temp the engine runs at for most of it's operation which is determined by the thermostat not the outside temp.


I found a earlier post (05) on this same engine oil question might be interesting.
http://www.irv2.com/forums/f84/ford-...w20-33479.html


Many postings on this V10 engine oil just searching google:
https://community.fmca.com/topic/429...ed-oil-weight/

[EdInArk]

Originally Posted by vito.a

I really don't think it's that big of a mistake. If your engine was 2 years newer it might even specify 5W-20.
As the EPA standards get tougher and CAFE (corporate average fuel economy) kicks in manufacturers are specifying lighter weight oils with little to no change in the engine.
On top of this you used full synthetic which is definetly better than 5W-30 non-synthetic.
I would run the oil and not worry about it. Just go back to 5W-30 at the next change interval.

Or, even one year newer

Our 2017 specifies 5w20. I do use a full-synth 5w20.

[Mudfrog]

Originally Posted by grindstone01

That may be true for the first number which is the viscosity at cold start up temp and is usually a short time period. The second number is the viscosity at 100c or operating temperature which is usually the temp the engine runs at for most of it's operation which is determined by the thermostat not the outside temp.

Very true, I would not want to run 20W in an engine that required 30W. My reply above was made because the manual showed 5W-20 as being one of the recommendations. I went back and read again though, and spotted the footnote in the manual stating to use the numbers on the oil fill cap. I've since edited my previous post.

Most owner's manuals have an "engine oil viscosity" chart inside their pages. They normally have a "preferred" viscosity that covers the widest temperature range. There is usually an optional viscosity, sometimes more than one, that the manual says is ok if outside temps are in range. I'm kinda surprised the Ford manual doesn't have it.

[Ray,IN]

FWIW, the engine in a MH is classed as severe-duty use. Were it I in this situation, I would drive around locally for 20 miles then change to the specified oil-including filter change. Sure you're out about $50, but you just flushed the engine with a high-grade oil and discarded contaminates in the old filter. That has to be worth something.

[Waiter21]

If it was mine, its not a big deal... leave it alone..

In my MH, I use 10w30.. In my cars I use 5w20 or 5w30 in the winter and 10w30 in the summer..

[04fxsts]

Interesting, our 2015 V-10 and my 2004 F-150 with the 4.8 both call for 5W-20 and also use the same oil filter. Jim.

[starcrwzr]

Well, I've decided to leave in the 5W-20. Did some research and got lots of opinions from people that said it would be fine. I was curious and downloaded the 2017 F53 manual, and guess what, 5W-30 is not even listed, only 5W-20. I seriously doubt there were any major engine changes between the 2016 and 2017 so I think I'm safe. Thanks for the input everyone.

[AITG]

FWIW: there's a tech on YouTube who has quite a following as Fordtechmakuloco. He recommends 5W-30 for cam phaser life. Since he worked in a dealership and did a lot of engine work I chose to take his advice. However, one change of 5W-20 won't make a difference. My V10 factory fill was 5W-20. After 1100 miles I went to 5W-30.

[TLGPE]

Maybe they just had some left-over filler caps.................

Ya never know.

Tom