Viscosity decrease after 8 hours track time?

[GTP]

I plan to do 4 track days in a row this year and I don't want to change oil until after I return home.

I run 40wt oil and CHT is under control at 228F. I drive hard enough for the oil life to be gone by noon the second day.

Will a Blackstone UOA show a drop in viscosity afterwards?

It is likely to be my first event in 2025 and so I won't have the opportunity to send in a sample after, say, a track weekend to test this out.

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[K4fxd]

Is it straight 40 weight? If it is a 5w-40 or 0w it will sheer out of grade.

I'd change oil halfway through but a straight 40 might hold up.

 

[S550HPP]

5-10W 40/50 Pennzoil Euro Synthetic no need to change can run it hard for long time.

Oil mainly breaks down because of heat ( natural gas synthetic han take it easily) and turbos are extremely hot so NA no big deal as well as time and extreme heat breaks down the critical additive package.

I would make sure have fresh 100% synthetic in the trans, diff and brake fluid because it gets tortured.

 

[WItoTX]

228 oil temp after a 20 minute stint is pretty impressive. I dont stay that low even at AutoX events. Track days I'm usually at 250 by lap 2-3.

I'd still change the oil after each event. It's cheap insurance and gives you an opportunity to check all bolts and generally just inspect the underside of the car.

 

[GTP]

I will be away from home by 5 hours. There is plenty to do during down time and I don't want to add a remote oil change to the list.

I normally run Mobil-1 0w40 Euro for track days. I could switch to 5w50 for this trip. ?

 

[tosha]

I honestly don't think your car will crack in half if you do 4 days instead of 2. Most of my track weekends now are 3 days in a row with at least one day being open lapping.

If you do 4 sessions a day 25min each, I personally wouldn't overthink it. If you want to be on the safe side, most tracks have performance shop that can change oil/tires for you.

 

[GTP]

Thanks. I'm not over thinking it. I'm just asking if anyone has experienced lowered viscosity as shown by UOA after extended track hours.

 

[GregO]

I will be away from home by 5 hours. There is plenty to do during down time and I don't want to add a remote oil change to the list.

I normally run Mobil-1 0w40 Euro for track days. I could switch to 5w50 for this trip. ?

Redline 5W-50 if you don’t mind the price.

 

[K4fxd]

This or run a straight 40 or 50 oil.

 

[Ewheels]

We're all just speculating at this point. If you want definitive data, you'd need oil analysis results. I'm not sure if it's exactly linear (four days of track use = x4 single day track use) but I agree with others; if you want to play it safe, change the oil after day two. It really only takes 30 min to do so and most tracks have a place to dump used oil.

Knowing your exact oil temps will also help. I know the quality manager at Philips 66 and he told me oil additives are only designed to withstand up to 270°F so anything higher than that and the oil is breaking down (at what rate, I don't know but it is happening).

 

[GTP]

We're all just speculating at this point. If you want definitive data, you'd need oil analysis results.
...

Agreed, as per my post #7 above.
Still waiting and hoping someone with direct UOA test will chime in.

 

[Ewheels]

Agreed, as per my post #7 above.
Still waiting and hoping someone with direct UOA test will chime in.

I believe @Flyhalf has plenty of oil analysis data he could share.

 

[GTP]

I believe @Flyhalf has plenty of oil analysis data he could share.

Yeah, probably. But I believe he said he changes oil so often that he switched to olive oil to save money. Pretty sure Blackstone won't process that.

I've done 13 changes in my car in 26k miles, because of a few track days per year.

 

[Flyhalf]

Ciao
Few considerations. Based on my 0w40 experience on my racecar

1. Viscosity doesn't change really.
What changes are the "quality" of lubrication and its addictive quantity.
2. Depends on many factors (quality of oil ,miles run, temps etc. Revving etc )
3.for testing I don't use anything else
BUT THE SPEEDIAGNOSTIX KIT.
it is made for mustang so you can pick your oil from DIPSTICK! so
You can definitely test it between events. You can inout all the info u want including your scenario of back to back track days. They will tell you everything.
Get your kit here

https://www.opmustang.com/store/p435/SPEEDiagnostix_Oil_Sample_Kit_-_Coyote_Specific.html#/

My example.
I used to change oil every event.
This time
I did 350miles at NATIONAL NASA RACING.
85f With 285f oil temps. i can guarantee i push the car ( right @Ewheels ?)
My sample came perfect.
He said to reach 1000miles and test again.

Hope this help

Ps. Olive oil was awesome. I made also many bruschetta!

 

[Ewheels]

i can guarantee i push the car ( right @Ewheels ?)

I can vouch for @Flyhalf
His history of transmission replacements (sorry, couldn't help myself ) and his growing collection of national titles are proof enough that he uses every available ounce of his car. Probably the fastest A10 mustang driver in the country.

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