Still no walmarts in OZ? Just wait a few years- coming to a corner near you. The Waltons are taking over the world.

 

Well I'm running 20/50 dino oil in my 4.6 and it's got 125,000 on it. No Problems. It burns a quart every 2,000 miles and has done this from brand new. When a motor burns this much oil from the beginning, this is not a close tolerance engine. Started with 10/30, then 10/40, now 20/50. Your timing chain will love you for it. Do you really feel comfortable driving in 110 degree heat with the AC on and oil that looks like water? Forget about gas milage...what about engine life?

 

"Do you really feel comfortable driving in 110 degree heat with the AC on and oil that looks like water?"

Yes. Next time you are doing that, jump out there and open up the drain and see just how thin that 20-50 is. It'll look thinner than water, too. These engines don't work on viscosity. They work on flow. There is a difference between tolerances of bearing and tolerances of seals, rings, etc. The latter will contribute to oil usage. The former will get eaten alive by oil that is too thick. Use the thin oil, your cam bearings will love you for it.

 

low tension rings are the reason for oil consumption on ford engines

 

usually valve stems in the case of a high mileage modular motor.

 

Yes, that is correct.

 

my buddy got a brand new ranger that called for the 5/20. He's an old school mechanic and thought he was being smart putting 20/50 in it. The engine developed a nasty sounding knock soon after. I'm don't know for sure if it was the oil, but I doubt it helped.

 

Well, I'm not saying to put 20/50 in a brand new motor. They need a thinner oil for break-in. I started with 5/20 for the first 25,000 miles on my 4.6 and then went to 10/30 and then 10/40 and now after 125,000 I'm running 20/50.
This is just what I'm doing, and to each his own, especially dependent of climate conditions. Where I live it never gets below freezing. I think it is more important to change the oil at regular intervals then what brand you are putting in. I plan on driving this 4.6 into the ground and will let ya'll know when it lets go.

 

I still say, unless you are having trouble holding good oil pressure, the thinner the better. You need flow to get the oil where it needs to be, like cam bearings etc.