Are the Ford 4.6 motors tolerant 40 wgt oils?

[gulfstream]

Greetings:

Could I get away with 5 and or 10w-40 oil in a 4.6 motor. Are the clearances tight? The motor has 260,000 plus original miles on it.

Thanks!

 

[dave1251]

Yeah. If you go south of the border 10W-40 is the light oil. My BIL uses 10W-30 in his 2004 4.6. There is a lot of people whom still subcribe to the theory lighter oil does not protect as well.

 

[Titan]

Get away with it? Probably. Go look in the Used Oil Analysis section though...I just put up a 4.6 Ford Modular engine with over 10,000 miles on a mix of 4 quarts of 5-20 and 2 quarts of 5-30, and I've never seen a better 4.6 report. SO, thicker oil certainly isn't required in these engines...I'm not sure what you are trying to accomplish. Does it "consume" oil now?

 

[ekpolk]

A couple members have experimented around and concluded that their 4.6L V-8s became sluggish and less responsive on thicker oils. I recall one specific example (can't recall the member) where the owner changed from 5w-20 to GC, which of course, is a very thick, nearly 40 wt, 0w-30. He said he didn't like the feel of it at all.

I'd suggest you do your own experiments to see what you prefer, in your car, under your unique operating conditions. The optimum approach would be to take your time, and combine both subjective observation with a couple UOA results.

 

[Panzerman]

Alot of 15w40 have the claim of being for mixed fleets of gas/diesel. F150s come with 4.6s, so Iam sure there are ones out here that get that. I dont think it would hurt a thing. When I was in Trucking with my parents, we use 15w40 in everything because we had it bulk, I know alot of people that did and still do. This was in Pennsylvania, where it gets very cold, without any problems. 15w40s are a tough, clean oil that is very durable, the most durable, if warranty isnt a issue, use it with cofidence.

 

[mikemc]

What has the engine seen thus far? Whatever it has been using seems to work given the miles. If the UOA section is a good yardstick, these engines seem to thrive on thinner oils.

 

[Lost1]

Originally Posted By: gulfstream
...The motor has 260,000 plus original miles on it.

Then I would keep using exactly what you've been using.
Why fix something if it isn't broke...

 

[ConfederateTyrant]

Amsoil ASL and TSO thickened into 40 weights (mid 13 cSt area) in my 4.6 engine and I never knew the difference. Performance and gas mileage did not change.

I am going to try the 0w-20 in my car next and see if things change. Though It'll be 4 quarts of 0w-20 and 1 quart of Series 3000, it should still be a 20 weight.