Curious -
Why does ford recommend 5w30 in the 4.0L SOHC and 5w20 in everything else?
2nd question - Is pennzoil synthetic any good? compaired to Mobil1? - compaired to Ford simi synthetic?

Thanks guys
JJK

 

Ford still recommends 5W-30 for the 4.0L OHV, too.

 

Those are not US-designed Ford engines, but Ford of Germany designs. The German engineers probably refused to "sign off" on the use of 5W-20. They probably had to be dragged kicking and screaming just to approve 5W-30 non ACEA rated oil.

Jim

 

I use 10W-30 or 10W-40, 37k and no problems. I think the reason they 'suggest' these is because of fuel mileage requirements. Since the 5W is a lighter oil than the 10W, theoritacally it won't weigh as much on the internals, and the tiniest fraction of a miles per gallon it may increase multiplied by the number of engines out there decreased x number of barrels of gasoline wasted to running the engine.

Or else Ford got a helluva deal on 5W-20 and since it came from the factory with it, made it the weight of choice. I just went with 10W-30 because that's what I run in the rest of my 5 vehicles. The 10W-40 was bought because they were out of 10W-30...

 

Mobil 1 is fully synthetic, while I think Pennzoil is based on a highly processed dino juice.

 

I don't know how much has changed in the oil systemof the 4.0 engines compared to my 2.8 and 2.9 decendents that I owned, but I ran 10w30 in both of those and they had not gave up yet at well over 200k. RAn plain old Valvoline all climate that some here seem to hate. I took the valve covers off of the 2.8 to replace the valve stem seals at 180k and every thing was spotless, clean enough to eat off of. The 2.8 was in a 1975 Mustang and the 2.9 was in my 1988 Ranger.
Dan

 

jimandmandy hit it perfect. It's a German made engine and they just can't bring themselves to "authorize" a "weak" American spec'd oil in an engine made in the fatherland( I'm mostly German so I can say it ). I think the Lincoln 3.9 V-6 made in Germany was the same. It's kind of ironic since at the time the Ford spec'd Motorcraft 5W-20 semi-synthetic was actually a higher quality oil than the previous GF-3Motorcraft 5W-30 "dino" oil or other GF-3 5W-30 "dino" oils. The new GF-4 Motorcraft 5W-30 is now also a "semi-synthetic" oil. My wife's 2002 Explorer with the SOHC 4.0L V-6 used the older Motorcraft GF-3 5W-30 for 5,000 oil changes and the used oil analysis of wear metals was real good. While you're under warranty and need to change the oil every 5,000 miles I'd have NO problems using the Motorcraft 5W-30 for the entire 5,000 miles, unless you beat the crap out of the truck and fall into the severe service interval. After you're out of warranty then you can use a true syntetic oil and go for 7,500-10,000 oil changes.

Whimsey