2017 Ford Focus RS - 2.3 EcoBoost, 39k, 5w-50 Amsoil SS, 5.1k miles

[Enviro5609]

I previously did a longer term interval stress test here

Thought I’d share a longer term update. Decided to go with just 5k for the OCI after the fuel dilution I saw last time. Ford’s intelligent oil life monitor said 25% at time of sampling. It does seem to be more than just a simple mile or time gauge. The longer term stress interval took it down to 0% at 10 months, 8.9k miles. This is 25% at 7 months, 5.1k miles. 1 year or 10k or 0% is the standard OCI per Ford.

Professionally tuned, KN filter. Bolt ons, but engine is stock. Catch can system installed.

This year I haven’t been able to go to the track or autocross, and it shows.

Interesting data point versus last year where it was being tracked and auto crossed spring through fall. Car is still tuned. Only difference is this 5k miles was just street driving only. Tuning an engine may increase the likelihood of some kind of sudden, LSPI/superknock event, but it doesn’t seem to promote any increased regular wear and tear.

Wear held up much better, as did the base number, but fuel dilution and shearing is about the same. Boron depletion continues to be rather quick.

Manganese is still showing up even though no Boostane or race gas was used during this OCI. Once that stuff gets in there, it sticks around, apparently.

It appears that this motor simply loves to shear down oil. I know the Motorcraft 5w50 got a lot of flak for shearing, but it’s probably just the design of the engine itself. DI, small displacement, high boost and high temperatures in this application. The fuel dilution isn’t enough to cause the shear from 50 to 40, in and of itself. At least I don’t think so.

I could always try another brand for comparison, but options for AP 5w50 are pretty few and far between. Redline is an option, but I already bought another 6l of Amsoil for the next change.


Takeaways— Track and autocross driving absolutely puts extra wear on the engine. Tuning alone doesn’t, if done well by a professional. 2.3 EcoBoost motors will shear just about anything and love to eat up boron additives. DI causes fuel dilution. MMT additives don’t go away quietly, even after an oil change.

 

[KCJeep]

What tune did you use and how much hp are you making now?

UOA looks fine to me. I wouldn’t do more than 5k regardless of use.

 

[Enviro5609]

What tune did you use and how much hp are you making now?

UOA looks fine to me. I wouldn’t do more than 5k regardless of use.

Randy at TuneWerks did the tune. Peak 342 hp and 407 torque at the wheels with a street dyno.

Hard to say what it is at the crank. With the drivetrain on these cars, parasitic losses are high and variable. The PTU is always engaged to the crown gear, and the RDU clutch packs switch on and off through a pull. Even if you put it in “dyno mode” to disengage the RDU for a chassis dyno, the PTU and rear drive shaft is still spinning. It makes coming up with consistent parasitic loss ratios difficult. It’s about 60hp and 100trq over stock at peak, which is about what we were aiming for. I don’t think I’ll ever know the precise crank numbers without pulling the engine and putting it on a dyno, and I’m not doing that.

 

[JoelB]

Man that thing must be fun to drive.

 

[Enviro5609]

Man that thing must be fun to drive.

It’s an absolute weapon. The acceleration and handling feels like a proper rally car.

Honestly though, I still do miss my Fiesta ST for around town now and then.

With the RS, you either need to be on the track or breaking the law to really push it for more than a couple seconds.

 

[KCJeep]

Randy at TuneWerks did the tune. Peak 342 hp and 407 torque at the wheels with a street dyno.

Hard to say what it is at the crank. With the drivetrain on these cars, parasitic losses are high and variable. The PTU is always engaged to the crown gear, and the RDU clutch packs switch on and off through a pull. Even if you put it in “dyno mode” to disengage the RDU for a chassis dyno, the PTU and rear drive shaft is still spinning. It makes coming up with consistent parasitic loss ratios difficult. It’s about 60hp and 100trq over stock at peak, which is about what we were aiming for. I don’t think I’ll ever know the precise crank numbers without pulling the engine and putting it on a dyno, and I’m not doing that.

Nice. I've toyed with the idea of a Ford Performance or JB4 tune but I probably won't get beyond kicking the idea around.

 

[buster]

So it looks like the 5w50 is going to inevitably drop down to a 40 grade which is not surprising. The low Fe could be due to no autocross driving. It is interesting to see the trend where there was autox and no autox. I'm not sure what to make of the manganese.

The SS 5w50 will run very clean. Entire SS line is very premium. I'd probably drop down to SS 10w30 or try Red Line. Red Line is one of if not the most shear stable oil I have ever seen. HPL no VII would be another one, or any of their oils as they too use a very good VM. Red Line though has always stood out to me for its shear stability.

 

[Enviro5609]

So it looks like the 5w50 is going to inevitably drop down to a 40 grade which is not surprising. The low Fe could be due to no autocross driving. It is interesting to see the trend where there was autox and no autox. I'm not sure what to make of the manganese.

The SS 5w50 will run very clean. Entire SS line is very premium. I'd probably drop down to SS 10w30 or try Red Line. Red Line is one of if not the most shear stable oil I have ever seen. HPL no VII would be another one, or any of their oils as they too use a very good VM. Red Line though has always stood out to me for its shear stability.

This brings up a really interesting question, one which no one who is into the RS platform can agree on.

Why 5w50? And does the brand matter?

Ford spec'd 5w50 for the Focus RS in the US and Australia. Same as the GT350/500 and GT. But why? Officially, Ford says its because of the increased heat, compression, and demand on a performance engine designed for track use. The same 2.3 engine in the Mustang is spec'd for 5w30, although that has less HP, Torque and Boost. No other factory 2.3 was pushed as far as the RS. But the oiling system itself is the same. Only difference between the 2.3 RS block and the other 2.3s is the head and turbo. The short blocks are identical. So its not the tolerances in the bottom end that necessitate 5w50.

In Europe, they spec'd 0w-40 for the RS. Same engine, same performance map. So it can't just be performance only dictating 5w50. Is it just climate/temperature? Oil availability ? (There wasn't a Motorcraft 0w-40 in the us at the time, but there also wasn't any 5w50 in Europe. The GT there was spec'd to use Castol instead).

Further, did Ford spec Motorcraft 5w50 knowing that it was going to shear down? (The owner's manual advises to use fresh fluids and then change oil after every track use, but that could also just be to cover potential warranty claims). If so, would running a more shear stable 5w50 might actually put it out of spec and cause issues on cold starts over time? Is 0w40 fine only in European weather, or would it actually be better for daily driving without track use? Should you switch to 0w40 for the winter?

Without a Ford engineer who worked on the project, there aren't any real answers. Not without a bunch of testing I'm not willing to risk. The long term stress test I did was enough for me.

I went with Amsoil because, at the time, Motorcraft 5w50 was only SN+ rated, and not SP. Most of the engine failures I've seen on these cars, even fully stock, appear to be LSPI related (owners reporting sudden engine failures at low RPM/high load where the piston is shattered and the rod sent through the side of the block). So I wanted that SP formulation with less calcium and the most LSPI protection.

Now Motorcraft 5w50 is SP rated, apparently. Maybe I'll switch back, but I've been happy with Amsoil thus far.

(Manganese was from the race gas/MMT additives from tack days and tuning. It appears to have stuck around even after the change, probably residual deposits).

 

[KCJeep]

Don't usually think of LSPI in anything larger than 2.0 but the hp per cylinder is quite high here so could be.