Thickest oil used in Ford 4.0?

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What's the thickest oil anyone has used in a Ford 4.0 V6 (2007 Mustang)? Of all the oils I've used in it,so far the "thickest" 10W30 has been the smoothest. Synths make it feel loose and sloppy. Thinking about trying a mineral 10W40. Anyone ever use or try a 40 wt oil in one of these engines? I was thinking someone here did but I can't remember who it was.
 
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I'm sure someone somewhere runs a 50 weight in that engine, but why?
It's a plane Jane v6.
Run whatever 20 or 30 weight and it will last forever.

Personally I'd run 10w30 Maxlife and call it a day.
 
Yep 10W30 Maxlife. That's what I have currently in my Explorer with the 4.0. Runs perfectly. I believe Maxlife is one of the thicker 10W30's.
 
Thicker is not the right choice for that engine.

It's a low revving, overhead cam, hydraulic ROLLER engine with about 300 feet of timing chain and teflon guides.

You want a high-detergent 5w30. Period. Whether you choose to make the wrong decision is your own accord.

-D
 
Originally Posted By: DemoFly
Thicker is not the right choice for that engine.

It's a low revving, overhead cam, hydraulic ROLLER engine with about 300 feet of timing chain and teflon guides.

You want a high-detergent 5w30. Period. Whether you choose to make the wrong decision is your own accord.

-D

What's the cause of wear on Teflon guides? Must be operating in boundary lubrication so wouldn't a thicker oil possibly reduce the wear? The timing chain system is a bit of a weak spot on these motors I believe.
 
My father drives a 2007 Ranger 4.0. Mobil 1 5W30 since new. Its nearing 200,000 kms on it and sounds like the day he bought it. It uses no oil. He just uses Fram cheap oil filters too.
 
When I had a 2005 Mountaineer with the 4.slow, I ran RT6 in it for back to back intervals one time. No issues and I didn't notice anything different than running a normal 5W-30.

Traded it in at 100k miles for a minivan, so never experienced any of the chain issues.
 
Most of the chain issues were in pre-2004.

My 2002 had it was an engineering issue.. not an oil issue.

Those engines were never spec'ed for 20wt

so a thicker 5w30 or even m1 0w40 are good choices.
 
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I have a 2001 Explorer Sport Trac and I have used Mobil 1 5W40

but I don't think they make it anymore. That engine ran great

5W40.
 
Originally Posted By: aquariuscsm
Synths make it feel loose and sloppy.


That's an interesting observation. People say synths being slippy-er than conventional is just a myth, but I don't know. Observations like this, and the drain-off effect seem to suggest otherwise.
 
Originally Posted By: Merkava_4
You could try a thin 10W-40 like Chevron Supreme. Good oil.


Isn't VWB also one of the thinner oils? GTX and PYB I'm thinking are the thicker ones?
 
Having a lot of experience with the 4.6 2v I learned some neat tidbits.

The chain guides wearing is highly dependent on the chains themselves. If the chain links were stamped out late in the die's life it makes the edges rough and will rip the plastic guides up faster than if the links were stamped out when the die was new.
Thicker oil does incur a fuel economy penalty however a 40 grade is far better than a 20 grade in respect to the tensioner guides wearing out. It leaves behind a thicker oil film at start up which from what I've seen with mine is the primary time of wear.
Mos2 seems to help. When I put a new tensioner and guides in my 2v at 200000km I also began using mos2. When I tore that engine apart at 300000kms and compared the wear on the guides compared to new ones the only wear I could see was at the ends,and it was very slight. When I originally replaced them at 200000km on the engine the guides were so badly worn the chains actually dug into the metal behind the guides and effectively destroyed everything necessitating complete replacement of everything behind the timing cover.
The only change few the first 200000kms and the last 100000kms was mos2 and I ran a 40 grade during the summer. The car also got a nitrous kit at the same time as I did the chains and tensioner.
So the combo of using a 40 grade and mos2 almost eliminated visible chain guide wear.
So fwiw thicker oil can in a real sense lessen guide wear however an engine is more than just chain guides,so you've gotta consider the whole package.
 
Originally Posted By: aquariuscsm
Isn't VWB also one of the thinner oils? GTX and PYB I'm thinking are the thicker ones?


You are correct sir yes.
 
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