I have had a 2000 Excursion with V10 for a long time. This truck uses 5W30 motor oil and I have always used it. Truck runs real good with just under 100,000 miles. I recently bought a 2005 Excursion with V10. I just noticed this V10 needs 5W20 motor oil. I intend to put the 5W20 in it, but I always thought they were identical engines. If the engines are not identical, I could undersatnd this.

I'm pretty sure this was probably discussed before, but new posts get new answers!!!

What's the difference - both in the engine and in the motor oil. I'm pretty sure that the basic difference in the motor oil is that the 5W20 is a little more viscous than the 5W30 at running temp. Would this cause the oil to burn off?

Also, I heard something about semi synthetic. Is that what 5W20 is or is that something for a different thread.

Thanks everyone.

 

I believe sometime in 00 they switched over to the PI heads. They changed the oil spec. 5w-20 is actually less viscous than 5w-30 at temp. Oil burn off will be influenced more by how well the engine was broken in, I believe. Semi-synthetic means it is part petrolium and part synthetic in a blend. The other options are full petrolium and full synthetic. I just switched to 5w-20 full syn with Castrol Syntech.

 

Differiant engines....the 05's and up have 3 valves per cyl. among other things. Since the 05 is used i'd run Motorcraft 5-20 semi-synthetic (factory fill on 08 and up)

 

Excursions never got the 3 valve in '05.

 

Really...well darn it

 

I spent a few hours researching and did not find any mechanical, dimensional, or part number changes when the suggested oil changed.
I suspect it was a CAFE and product availability decision.
A 5W20 will give ever so slightly better mpg. And 5W20's weren't very common in '97 when the engine was intro'd. It would be quite interesting to find out when Ford released Motorcraft oil in 5W20.

My opinion: Run either weight in any year engine. The difference really isn't that much.

In general, a grade up or down is quite fine in any engine. Even 2 grades down in frigid weather or 2 up in hot weather is not likely to hurt anything in the vast majority of engines. Maybe even 3 grades with full synthetic.

BTW, Castrol Syntec is actually a blend.... Several years ago there was a lot of legal system time spent defining what a "full synthetic" is. Mobil said it had to be 100% synthetic base stock, Castrol said it didn't. Castrol won.
Result: Massive head scratching and confusion.... I believe Mobil 1 has since changed to a semi-synthetic to remain cost competive. Both are still extremely good oils.
If you truly want full synthetic, you have to do a lot of research. Redline still is.

 

I have a conspiracy theory. Ford new they were going to eliminate the Excursion, but they didn't know when..... So they went to a 3V engine and put it in the Super Duty. Then they counted up how many 2V engines they had laying around and that was it except for a small surplus that they needed to keep.

I'm pretty sure it is an identical engine. No Excursions got the 3V engine for reason above .

 

That definitely reinforces what I thought. Thanks.

 

Thank you. Great post!

 

I believe there had been discussions about swapping out the engine in the Excursion to the 3 valve, but I think the end result was that it was too difficult. You'll need a new transmission because the '05 had the Torqshift.

You may need to change the PCM and bunch of other sensors, I think. Not worth it.

 

There is a ton of discussion out there on the web about 5w-20 engine oil. CAFE is the main reason for the development of this oil. If it were my Excursion I would not run 5w-20. I had a 2001 Excursion with the V-10 and I ran 10w-30 Mobil 1 in it. Try "BOB IS THE OIL GUY.com" (leave out the spaces when you type in the address) and seach CAFE standards and read about HTHS. You can make up your own mind then. Like I said...I would not use it!

 

Model year 2001, they went with 5W20 across the entire fleet. Whatever the reason, that's the cutoff point.

I still ran 5W30 because the timing chain always sounded louder with 5W20

 

Same here. I use 5-30 timing chain sounds quieter over 5-20.

 

Straight 20 weight synthetic racing oil is rated at 5w20 just because thats how it performs compaired to convention oil. I did not search but I think all 5w20 is synthetic.

 

Well dang. I guess I went full synthetic blend then. I read all over it to see and couldn't really tell.