I want to go to a synthetic, but I was wondering what Ford Mo.Co. was tying to achieve in the first place by using the 5w-20 in the 5.4L (?)

I want to go with Mobile 1, but would the 0w-30 or the 5w-30 best maintain whatever Ford was trying to do with the 5w-20?

 

If you want to use mobil 1 product that is closest to the spec to a 5w20.

You can use the 0w30. It has a viscosity of 9.7cSt @ 100c.

To be classified as a 30wt. it must have a viscosity of 9.3cSt.

Whereas the 5w30 is listed as 9.9cst @100c so it is a little thicker

For instance amsoils 5w20 is 9.0 cSt which is just barely a 20wt.

So with the 0w30 you would be .4cSt over what is considered the maximum viscosity for a 20wt oil.

Really its all really close and in reality most conventional oil's will thicken up to a 30 wt anyhow over a 3000 or 4000 mile drain.

For instance a conventional oil 5w20 with a 100c viscosity of 9.0 might have a wt. increase of 14%.

So over the time the oil is in the engine, if it does increase 14% the 9.0 would go up 1.26cSt, which would make it 10.26 cSt. about a midweight 30 oil.

So you see you will actually be closer to the desired grade after a few thousand miles using Mobil 1 0w30 than you would use a conventional oil.

I hope all of this made sense, if you need more explaination let me know I'll try to clarify!

 

MSparks, what weight oil are you running in your truck? Are you using Amsoil or Mobil 1?

 

I'm Running Amsoil Series 2000 0w30.

Though my truck is a 97 and calls for the 5w30. I have talked with Amsoil's tech services numerous times and their recommendation for anyone with a truck that calls for the 5w20, is to run the 0w30 if they want the extended drains. Now they have a full synthetic 5w20 but it is only the XL7500 which is good for 6 months or 7500 miles.

 

....Tony walks into the corner and curls up into the fetal postion and begins to cry ....


...man am i tired of this subject......


Tony

 

So who forced your finger to click on the thread???

 

Msparks: Thanks for the info. I'll try 0W-30 in synthetic. Sorry I posted this under ENGINE as I couldn't find the BORING category....Actually I thought it was a legitimate Q, thanks.

 

It was a very good question Winder. Once again MSparks reports some interesting oil information.