Part 2- 2017 Ford Focus RS, 2.3 EcoBoost, 31,700 mi; 5w50 Amsoil SS, 7,000 miles and counting

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About three months ago I started an ongoing maintenance interval testing program for my Focus RS. I am trying to determine the actual OCI for this vehicle.

Part one is available here, with all the background on this car. It’s a 2.3 GTDI car, conservatively tuned, used for daily driving in the city, with about 12-14 autocross events and the occasional track day per year.

I decided to do the next testing at 7k instead of 8k, as I initially planned. The goal here is to keep running the oil and testing it until the tests say change it, and then I’ll know what the actual interval is.

I was honestly concerned the oil wouldn’t make it and I’d be hurting the car. But it seems to be doing ok. 3k miles and nothing has really changed except for a couple things as noted below.


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Gas dilution is up. As expected. Boron keeps going down as the additive package gets used up. Seems like the shearing out of spec has stabilized, as has the base number. Maybe this engine’s physical design contributes to the initial shearing? 5w50 is an unusual spec for a 2.3l 4 cyl., but it is putting out 400 hp/trq and peak boost around 23 lbs. The owners manual says change the oil after every track day, so maybe the shearing is expected and the heavy weight is for surviving the heat and shear on a track day. This engine does get very hot when you push it.

I used Boostane (very controversial, I know) only for two autocross events. It’s an MMT based octane booster. I was getting some negative corrections during autocross, and I decided to run some octane booster to see if it was false knock from debris on course/exhaust set up or actual knock. That’s where the manganese is from in the sample.

Would like to get your thoughts on whether I should keep the experiment going or change the oil. Only one autocross event left for the season, then it’s shut down to be a daily driver only until next March. At that point it will be 13 months since its last change.

Edit -typos
 
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One event left might as well take it for another spin...
Not sure how these engines wear but a bit higher than I'd think. It's not out of line for your type of use though. Pretty sure you're using oem spec'd grade 50 so you're covering your bases there. I like your idea to keep record & compare for your RS.
 
To add another data point for the ongoing debate on air filters. This car is running a K&N filter the entire life of this oil. So interpret the silicon and sodium/potassium numbers with that in mind.
 
As I'm sure you are well aware, Ford Ecoboosts put a lot of fuel in the oil. Extended drains are usually not in the cards for these motors, even with a great oil like Amsoil SS. That iron is already pretty high (though not dangerously so). Did you have the cylinder head gasket recall performed?

Asmoil SS is a very shear stable oil, and it has already sheared well out of grade. Starting viscosity per Amsoil is 19.4 on their data sheet. If it were me, I'd change this oil, especially if you plan on tracking the car again. I track Mustangs, but run with plenty of RS guys, and they see very high oil temps on a road course, sometimes north of 300 degrees. You definitely want a 5w50 in that circumstance.
 
To add another data point for the ongoing debate on air filters. This car is running a K&N filter the entire life of this oil. So interpret the silicon and sodium/potassium numbers with that in mind.
The new Brand Ranks just posted a video, yesterday I think, that showed K&N being very inefficient but has a massive load capacity to go many miles before cleaning.
 
As I'm sure you are well aware, Ford Ecoboosts put a lot of fuel in the oil. Extended drains are usually not in the cards for these motors, even with a great oil like Amsoil SS. That iron is already pretty high (though not dangerously so). Did you have the cylinder head gasket recall performed?

Asmoil SS is a very shear stable oil, and it has already sheared well out of grade. Starting viscosity per Amsoil is 19.4 on their data sheet. If it were me, I'd change this oil, especially if you plan on tracking the car again. I track Mustangs, but run with plenty of RS guys, and they see very high oil temps on a road course, sometimes north of 300 degrees. You definitely want a 5w50 in that circumstance.
Yes, head gasket was done by the dealer before delivery. It was a later production date 2017 and not sold to the first owner until 2018, so it was caught before it was put on the road. I got the paperwork from Ford OASIS (or whatever it’s called now) to confirm.

They did a poor job and created an oil leak in the valve cover and front cover with a horrific RTV job, but I’ll let any former Ford Techs here speak further to that. That was all fixed since I bought it.

If this was the spring, and I had a lot of hard driving to go in the next few months, I’d definitely change it out. But since it’s got one last autocross and about to do nothing more than go to work or snowboarding trips for the next 4 months I think I’ll keep the experiment going just to get the data.

I know exactly what my use case does to these kinds of engines and am under no illusions that I’m going to need to pull it at some point and build a new motor. It’s not if, but when. That’s in the plan so I’m not here trying to find a silver bullet. Just documenting a season of use for science and for others. I’ve read so much speculation on various forums as to the oil on this car and when to change it, but no actual hard data.

Edit— to add further context, Ford Europe recommends 0w40 in this car while Ford US specs 5w50. There’s been no official explanation for the difference.
 
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Edit— to add further context, Ford Europe recommends 0w40 in this car while Ford US specs 5w50. There’s been no official explanation for the difference.
I'd imagine expected ambient temperature has something to do with it. You don't typically see Texas or California type heat in Europe. Ford has to cover their basis. The real question is what does Ford in the middle east, Ford Australia, and Ford in Asia recommend? If those are 0w40 too, then that would be weird, because those places get hot.

For daily driving 0w40 would be fine, even for an autocross. Open track work I'd say no, would thin too much.

I ran 0w40 in my 2012 GT on the track in Texas. I was ignorant as to oil temps and not a fast driver, but never the less it didn't grenade. My 2016 5.0 Supercharged F150 ran 0w40 as well for drag racing, but that was an entirely different use case and she never ran hot. I did run 5w30 Amsoil SS in that same truck, and had fuel dilution issues and high iron, so I went up a grade and iron levels lowered.

GT500 gets 5w50, and that oil is spent after a track weekend.

Sorry I'm rambling. I love your car BTW, an RS has always been a dream car of mine.
 
I'd imagine expected ambient temperature has something to do with it. You don't typically see Texas or California type heat in Europe. Ford has to cover their basis. The real question is what does Ford in the middle east, Ford Australia, and Ford in Asia recommend? If those are 0w40 too, then that would be weird, because those places get hot.

For daily driving 0w40 would be fine, even for an autocross. Open track work I'd say no, would thin too much.

I ran 0w40 in my 2012 GT on the track in Texas. I was ignorant as to oil temps and not a fast driver, but never the less it didn't grenade. My 2016 5.0 Supercharged F150 ran 0w40 as well for drag racing, but that was an entirely different use case and she never ran hot. I did run 5w30 Amsoil SS in that same truck, and had fuel dilution issues and high iron, so I went up a grade and iron levels lowered.

GT500 gets 5w50, and that oil is spent after a track weekend.

Sorry I'm rambling. I love your car BTW, an RS has always been a dream car of mine.
Ford Australia also spec’s it with 0w40. There have been countless forum pages spilled on debating oil on this car, hence my experiment. It is interesting that it sheared the 5w50 down almost immediately and then stabilized.

The prevailing wisdom was that motorcraft didn’t make a 0w40 in the US, and that may be the real reason why. Temps made sense, but then Australia throws that for a loop.

Or maybe it really does need 5w50, but they put 0w40 in it in Europe and Australia to meet more stringent MPG/emissions standards there.

Ramble away. Always nice to get some feedback from a Ford guy.

My autocross group is mostly Subarus, Miatas and a some Mustangs in CAM, but the Mustang guys are really more Mustang than Ford, if you know what I mean.

There’s an awesome guy who actually runs his Ford Fusion Sport that’s been tinkered with who loves my RS. And there is a guy who runs a Lancer EVO also loves the car. But for most people, they don’t seem to get that this car is just a little different than anything else Ford made at that price point. Probably never will again.

Ford GT is my dream car. Wanna trade? ; )
 
If you are in a warm enough area, and you prefer Amsoil, would Dominator 15W-50 be a better choice that would shear less?
 
If you are in a warm enough area, and you prefer Amsoil, would Dominator 15W-50 be a better choice that would shear less?
Probably it would shear less? But I’m more worried about LSPI in this engine than the shear and fuel dilution. Dominator is a great oil but its additive package isn’t designed with LSPI and daily driving a GTDI engine in mind.

And I’m in the northeast.

If this was a track only car then I’d probably try it out, yeah.
 
Since there is more fuel present in the latest sample, which lowers viscosity, but the viscosity is basically the same, that indicates that the oil itself has started thicken. That could be due to oxidation and with that there is the concern about piston/ring deposits increasing. Another possible cause of thickening is there could be more volatilization of the less viscous portion of the base oil compared to the more viscous portion. 7000 miles is a long interval for a high HP turbo engine that gets tracked, even for a great oil like Amsoil SS. The appropriately conservative best choice to make is change it soon. It’s easier to keep an engine clean than to try to make it clean after it no longer is.
 
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