HPL premiums plus 5w30 PCMO. 4200 miles. 2015 Fiesta ST

Joined
May 19, 2022
Messages
43
The car has 162k miles and has a hybrid turbo. It runs E30 (91 mixed with e85) fuel and dyno’d 307 whp a little over a year ago. It’s tuned by Randy Robles from Tunewerks (formerly with Mountune). I’ve owned the car since 10k miles and it’s never skipped a beat.

This is my daily driver and, while the dilution is high, i don’t think I have a leaking injector. But I am going to replace them anyways here pretty soon considering the mileage.

This is the first UOA I’ve done on the car ever. The main reason I wanted to do one is to see how long I could run this oil. And it looks like I changed it at the right time.

I have the no VII HPL in there now and I’ll do a UOA on that. If fuel dilution is still that high or higher, new injectors are going in
IMG_2233.jpeg
 
Last edited by a moderator:
OT: I wish Ford still sold the Fiesta ST here in America...the 1.5T 3 cylinder Dragon engine is a perfect fit too.
 
You can't ask for much better than that. Despite the 4.5% fuel dilution, the KV100 is still in 30 grade range, the TBN is still higher than many common brands are starting with lately, and the wear numbers are excellent. Great report.

I know Randy from his days at FSWerks. I haven't spoken to him in years.
 
I get close to that fuel dilution at 3000mi in my '22 Subaru Crosstrek GDI. Very common in the Subaru GDI engines. It's the nature of the beast in these engines. Is yours GDI? If so, that isn't bad at all and I would no waste money replacing injectors. Your viscosity is fine so I don't see a huge issue here...
 
I get close to that fuel dilution at 3000mi in my '22 Subaru Crosstrek GDI. Very common in the Subaru GDI engines. It's the nature of the beast in these engines. Is yours GDI? If so, that isn't bad at all and I would no waste money replacing injectors. Your viscosity is fine so I don't see a huge issue here...
The Fiesta ST had a 1.6 ecoboost engine, so it’s a turbo direct injection engine. The engine is stock, but it’s highly modified with a turbocharger upgrade, bolt ons and a tune. I really don’t see an issue here either, I was expecting to see some dillution, but I was hoping for less.
 
3-5k miles or whenever the oil started to smell of fuel
Very wise choice. I know the 3k OCI is mocked here on BITOG. But if you keep an open mind for a moment, and you ask yourself, would anyone doing 3K OCI with the cheapest conventional oil ever get sludge, varnish, or gummed up piston rings, the answer is likely no.

So why do so many cars have sludge, varnish, and gummed up piston rings?
In my opinion, the reason is the oil change interval they are using.
 
On the fuel dilution, it's worth noting that what you're seeing there is about half or less than half of the actual amount of fuel entering the crankcase. With E30, the fuel is 55-65% evaporated at 210-220°F operating oil temp. What you're seeing there, that 4.5%, is the remainder that has a boiling point higher than the oil sump temp. These are the "heavy ends" of the fuel like toluene, xylene, ethylbenzene, and various aromatics and n-olefins. The real amount of fuel entering the oil is closer to 10% before the evaporation.

This is why short tripping is so bad for fuel dilution because the oil isn't getting hot enough to boil the light ends off so more accumulates. You also have more fuel physically entering the crankcase due to rich warmup cycles and reduced fuel vaporization in the chambers.
 
On the fuel dilution, it's worth noting that what you're seeing there is about half or less than half of the actual amount of fuel entering the crankcase. With E30, the fuel is 55-65% evaporated at 210-220°F operating oil temp. What you're seeing there, that 4.5%, is the remainder that has a boiling point higher than the oil sump temp. These are the "heavy ends" of the fuel like toluene, xylene, ethylbenzene, and various aromatics and n-olefins. The real amount of fuel entering the oil is closer to 10% before the evaporation.

This is why short tripping is so bad for fuel dilution because the oil isn't getting hot enough to boil the light ends off so more accumulates. You also have more fuel physically entering the crankcase due to rich warmup cycles and reduced fuel vaporization in the chambers.
This car is my primary transportation, it rarely gets short tripped. 66 miles a day, 5 days a week. I don’t let it idle to warm up, I just gently drive it until it gets warm enough. And, on the weekends, I carve canyons with the local car club here. I’m suspecting the dillution is just the modification level and tune, not to mention the fact that I beat on this thing constantly and it just takes it. It’s such a happy car 😅😅. It makes 26 psi starting at around 3k revs and still makes 20 psi at redline (I had the tuner keep the redline somewhat civilized at 6800 rpm’s. It’s common on these cars to go to 7500 rpm’s). Also, with the turbo upgrade, it makes over 100whp than stock, I suspect that isn’t helping.

Not that it’s relevant to the oil, but this car is also on coilovers, has full chassis bracing, bbk, etc. A lot of cars more expensive than mine can’t keep up in the mountains
 

Attachments

  • IMG_1693.jpeg
    IMG_1693.jpeg
    279 KB · Views: 15
^^
It's "double winged" to keep that beast from flying. :LOL:
Not gonna lie, it does make a difference through fast sweepers and at over 120mph. The back end of these cars is so light it helps it stick a lot more. Granted if the wing was actually part of the chassis it would work better, I understand that, and I know to some it can look a little silly. I love it though!
 
Not gonna lie, it does make a difference through fast sweepers and at over 120mph. The back end of these cars is so light it helps it stick a lot more. Granted if the wing was actually part of the chassis it would work better, I understand that, and I know to some it can look a little silly. I love it though!

I owned a small business that sold custom truck accessories, airbag kits, suicide door kits, rollpans, S10 Mirrors for your C/K 1500, etc., so I totally understand. I feel it's a personal choice with their own personal property. I enjoy seeing others "Mods" & have a deep connection to the modding world. I grew up in the days of cold air intake & body kits being the coolest thing since sliced bread. 1990's ha ha

Your car has form & function. (y) ;)
 
Top