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Oil Type

JDee

Ancient Racer
1,556
1,602
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W2W Racing
Exp. Level
20+ Years
halfway between Mosport and Shannonville
Gotta love these oil threads.
True for early 'yotes in the S197s, but for the S550 the Ford tech line guy told me 5W20 is fine for track as long as it is a high quality oil that meets the Ford standards, no off brand cheapie stuff.
Personally, I run 5W30. Just because heat is a thing....
 

JDee

Ancient Racer
1,556
1,602
Exp. Type
W2W Racing
Exp. Level
20+ Years
halfway between Mosport and Shannonville
Well, I guess if they made 940hp on 5W30 my little stock motor is pretty safe! These days I'm babying it anyway, self imposed 6500 rpm redline and I often only use 6K.
Because:
It's lapping, not racing, why beat the crap out of the thing?
And besides that, it's about the corners, not the straights.
IMHO.
 

Mad Hatter

Gotta go Faster
4,786
3,604
Santiago, Chile
I guess it depends on who is chasing you in corners and whether or not you want to win!! Crazy sport....
 
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150
130
CA
Well, I guess if they made 940hp on 5W30 my little stock motor is pretty safe! These days I'm babying it anyway, self imposed 6500 rpm redline and I often only use 6K.
Because:
It's lapping, not racing, why beat the crap out of the thing?
And besides that, it's about the corners, not the straights.
IMHO.
As HP levels increase, forces exerted on connecting rod bearings as well as the crank journal bearings increase.

One of many deciding factors for oil weight is what temperature the oil will spend the majority of it's life at. Just like brake pads, certain oils behave better/worse at certain temperatures.

From there, one needs to analyze the personal use case of their car and adjust oil weight accordingly. For higher temperatures you will likely want a higher weight. Ford essentially makes this assumption when they say they recommend 5W50 for track use, as they are assuming the oil will be hotter than it would be for street driving.
 
Redlines are there to protect the manufacturer's warranty on their engine....there's leeway for a little extra if you wanna go there. My Boss has a 7500 limit....I've never been over 6500 because I don't race and nobody's chasing me.....just for the record.....over 6500 scares me.............;)
 
The loop I get into with the dual specified oil weights is that, as far as I can tell, the main bearing clearances are the same between the Gen 1 Coyote and the Roadrunner variant at 0.0009-0.0018 of an inch. The 2011 Coyote was specified to use 5W-20 and didn't have any user manual subsection about track use back then. When I speak to those who understand the science in the industry, it seems like most point me towards 5W-30 - which is in line with some of the user manual supplemental information in later models.

I know we've gone over this before, but there seems to be no determinate conclusion on 'Did Ford specify 5W-50 on the Roadrunner because 1. It actually offers superior wear protection (even though it shears down to a 40 weight very quickly) or 2. because it's only available as a full synthetic at that weight and it's to keep penny pinching owners at quicklube joints from filling up their Boss 302 with corn syrup and filing into a dealer with warranty claims.' I assume Ford has a whole department dedicated to trying to predict the lowest common denominator of owner intelligence.

I also watched this series by Gale Banks when he visited Amsoil that covered a lot of the science and tried to absorb as much as I could. The timecoded part below was the most interesting point to me regarding oil weights and how they interact with the bearing surfaces:

It sounds to me that ideally you'd want enough rolling elastic contact (which I assume increases with viscosity, as more will stay on) to make up the oil clearance between surfaces. If you go too high on the weight, it starts rejecting oil and building up heat. Makes you wonder if members in hot climes running 5W-50 and strapping on larger and larger oil cooling systems may see an oil temperature reduction with 30 weight. Beyond tracking credentials, it makes you wonder if the fact that 2013 & 2014 Track Pack and Boss 302 Mustangs came equipped with oil coolers is partially or entirely due to that supposed increase in working oil temperature from having a 5W-50 recommended fill.

I feel like I'm smart enough to know to ask the question, but dumb enough to not know the answer, which is often the most infuriating place to be 😆
I mostly follow the recommendations of those that know better, which so far lands me with 5W-30, but still wanted to offload this from my brain since it was coming up as a topic again.
 

Dave_W

Cones - not just for ice cream
618
730
Exp. Type
Autocross
Exp. Level
20+ Years
Connecticut
I don't race and nobody's chasing me.....just for the record.....over 6500 scares me.............;)
Bob, you gotta understand, see, the Boss is a high performance car. You gotta burn that thing out... Put it in second gear and drive like 100mph.




"Any side street."
 
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Hold on......The Boss Feels there's nothing to prove to anybody........We know what we got...and that"s a lot...................end of story.......................Blowers are for ......................?????????????
 

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