I'm running only 5W-20 in my 4.6 from here on out, unless there is some massive oil price increase that forces me to dip into the 5W-30 reserves that are built up for the other vehicles.

06VtecV6, I can get full synthetic 5W-20 cheaper than I can get Mobil Clean 7500, since it's only available locally at Checker for $4.89, and only in 5W-30.

Well, first you've got to be willing to go 5k ..after you manage that hurdle, you need to integrate that to 6 months (as many of our membership are finding out that 10k a year is about it). Fear factor does play a role here. If they can manage to escape the 3k/3m prison, I don't begrudge them the added (and maybe totally unnecessary) security of using a synthetic. That's been PP's claim to fame, imo. It wasn't all that much more expensive than a conventional oil.

Crazydude, Run the MC5w20 and Motorcraft filer. That and the 4.6 were made for each other

MC5W20 is a solid oil and the yellow bottle is a solid oil too! Unless you are in extreme cold, want to extend your OCI out past 6 months or 6,000 miles (just a rule of thumb on my part nothing more) go with A or B above and pocket cash!! Your 4.6 will run forever on either oil. In this day and time saving money never goes out of style :!!

MC5w-20 is a well proven product and is a great value.

THey both are.. It would be hard to pick a favorite and since I may be moving soon I haven't been stashing..So I buy whatever is cheapest when I need to change the oil. I am tempted to start buying a bunch of both brands and move with it if I do decide to move.

That's funny....my last house hold goods trip on my move to CO was me a few house plants and 3 cases of oil (2 amsoil TSO's and a case of Delo) in my c4 corvette. Don't trust anyone else to protect your stash man!!!

I have a 2004 MGM also. I've tried Motorcraft, Mobil 1, and Pennzoil Yellow bottle. I have to say next time I will probably go back to the Motorcraft. I think it has a slight (be ever SO slight) advantage - according to my butt dynometer! :)
The Pennzoil Yellow Bottle is okay (no complaints) the Mobil 1 was unimpressive, especially for the price.

FWIW, all those oils were 5W-20 with a Motorcraft FL820S filter.

I just think the PP will keep things cleaner and another thing that is always on my mind 5w20 seems to do well but why out of this country does the same motors require 5w30? could it be c.a.f.e.?? Again i use 5w20 motorcraft in my modular v-8 and on my Moms grand marquis with great success and i use conoco phillips 5w20 and Mobil dino 5w30 at my shop in the big drums..
we use purolator oil and air filters and never had an oil related issue in the last 10 or so years that could point directly at our oil or filters..Another thing now i believe conoco phillips makes motorcraft oils but who is to say tomorrow someone else starts making it>? I know for sure the PP is unbelievable at keeping engines clean i saw it with my own eyes many times tell me your thoughts. :)

I have a hard time believing that the 5W-20 prescription is driven by CAFE...or at least SOLELY by CAFE. Our '03 Dodge Grand Caravan called for 5W-30 oil. Beginning in 2005, the same 3.3/3.8 engines were switched to 5W-20 oil. At the enthusiast level, we do not know if there were any design changes INSIDE the engine. EPA MPG estimates did not change. Is CAFE figured on the EPA estimate, at the whole number? If so, the CAFE figure would not change. If that EPA estimate is actually calculated out to the tenth or hundredth, and is only rounded to the whole number for the window sticker, then maybe CAFE was affected.

However, that reasoning must at least be questioned when Chrysler didn't switch ALL of its engines to 5W-20. The brand new 4.0L V6 in the Pacifica and new minivans...it's not even 5W-30 -- it's a 10W-30 in those engines. If CAFE is the reason for 5W-20, why not use 5W-20 in everything? Similar for Ford -- they began using 5W-20 in most vehicles, and retrospecified it for many. But I know that SOME engines were specifically DIScluded from that retrospecification...some Focus 4-bangers if I recall correctly. Ford stands to gain nothing in terms of CAFE for retrospecifying an oil...whether someone with an '01 CV uses 5W-20 or 5W-30 is immaterial to Ford.

CAFE may have SOME bearing...but in my estimation, it can't be the only reason. We've seen so many positive UOAs from 5W-20 oils that maybe, just maybe, it's at least as good as the heavier weights in terms of protection, volatility, and shear!

i agree with you on most of what you say
What i was saying is that why in other countries do they spec 5w30 on engines that call for 5w20 here in the us.. Also 5w20 reduces heat at the bearings because 5w20 flows better and reaches overhead cams faster than 5w30.
We use 5w20 on many engines at the shop and in my car also so im not totally against 5w20

I don't know. I'm sure it has to do with prevailing convention/tradition (much of the rest of the world still "likes" thicker oils), and then because of that, general availability of oil in the market place. You can't get 5W-20 oil in a lot of areas of the world. I can't answer why the same engine might use 5W-20 here, and 10W-30 or 10W-40 in other areas of the world.

I'm only thinking that the answer of "CAFE" to the question of why WE use 5W-20 oils may be partially true, and seems to miss some points of the discussion (like why automakers are still using 5W-30 and even 10W-30 oils in particular applications).

In addition, I might be wrong, but I don't think GM uses 5W-20 in ANYTHING, does it?

There is bearing design and an oil pumps capacity to consider when approving oil viscosities for an engine. THe engine designers can then acertain if it is safe to backspec an engine to 5w20 or not. If the engine designers find that 5w20 would fail to provide optimal protection for an engine it is not recomended.
Engine design is likely a major factor in why some engines still require 5w30 or even 10w30. THis could have to due with bearing formulas or other factors we are not aware of.

I agree...but we're curious about why the SAME engine takes 5W-20 over here, but over the pond might be specified for 10W-30.

I have to go with market availability and acceptabilty. For Years CAFE and Emissions requirement have been viewed as a somewhat negative aspect of American Auto Markets(and Japanese ones to an extent).. Emissions requirements besides there obvious benefits to the air quality have pushed improvements in ignition controls and fuel injection that have improved performance and longevity.
CAFE Does much the same thing.
What these requirements have done is helped to Form ILSAC as the emissions warranty requirements and increased fuel economy requirements put more pressure on auto manufacturers and PCMO Makers to work together to meet these goals and others.
In Many contries these emission warranties are not in place and the fuel use is controlled by taxing the end user not regulating the manufactuerer. In these countries there is no need for ILSAC certified oils and therefore PCMO standards are very different and what is marketed is based on that minimum standard.

This would explain why Many euro cars Require synthetic oils. THere PCMO's do not have to meet the stringent testing that ILSAC PCMO's do and therefore they require on viscosity and synthetic oils for there protection.