Oil Consumption?
 

So right before the track event this weekend at Sebring, I changed the oil to the point where I made sure it was filled exactly to the top notch on the dipstick.

After I cleaned off the car today, I checked the oil level, and noticed it was about 1/4 way down between the notches on the dipstick. Probably about 1/8 to 1/4 quart lower than I filled it, if I estimated the difference between the two notches correctly (seems to be a little over 1/2 qt from the bottom notch to the top notch).

Oil was checked both times in my garage on the same level surface. After the first day when I got home, and didn't really notice a difference in the oil level when I checked it, but after the second day I could tell the difference.

This weekend I ran 8 sessions total with the car across 2 days, 30 minutes each session, about 250 track miles. Car started the weekend with 998 miles on the odometer.

My question is, what kind of oil consumption are you all seeing after full track weekends?

I'm having a hard time reading the dipstick, but I'm sure mine has consumed oil in the 3500 miles since the last oil change. Can anybody provide tips on how to read a subaru dipstick? Two holes and reading somewhere in the middle is vague to me. (sorry for thread jacking)

I dont have an answer but...250 miles for a DE? Wow!

yeah... approximately 30 minute sessions, 4 times a day, 2 days over the weekend, turned out to be about 250 miles over the weekend. That's what you get with Chin Motorsports!! And heck, I skipped the 30 minute warm-up session and the hour long "happy hour" at the end of both days, so I probably would have close to 400 track miles this weekend if I ran every session.

Dunno if this helps any, but I changed out the factory fill at 2k miles and I replaced with Royal Purple 0w20. It took an entire 6 quarts of oil to reach the top notch on the dip stick. I was really surprised about that. Had no idea this motor took so much oil. It could also be accredited to the fact that 0w20's are like water. I'm now at 7k miles and due for a change. I was going to check how much oil she takes this time around to see if the first time might have been a fluke.

If you do find an answer please post up. I'm curious as to what the reason might be. Good luck.

not 100% sure on subi spec most import manufacturers stay 1qt per 1000 miles is normal oil consumption. i know it sounds like alot but it is what it is.

1/4 quart per 250 track miles is pretty good. You have to take into account that some of it is likely (most of that) being sucked through the PCV on high rpm engine braking vs. being blown past the rings like I think you are assuming. Pull your TB off (or just the accordion in front of it and push it open) and shine a light into your intake and I bet it shines back at ya!

This, these cars are giving uber hot oil temps with extended track runs. You may want an oil cooler. Mine is granny street driven and not consuming any oil, so I think the factory rings are solid in these cars, even though the manual says 1qt/600 miles is OK.

With the amount of torture the OP's engine is seeing I think it may be prudent to pull the DI injectors and inspect the O-rings, are you hearing any poping when starting cold or near redline?

great, thanks I'll check that!

Yeah an oil cooler is definitely going to help.

No popping at startup or redline at all, no CELs....yet, knock on wood!

Can you define "uber hot" and "extended track runs" and in what ambient temperature?

See the Avo testig thread they did some extensive comparison with their turbo vs NA on the track and saw 240F+ oil temps with stock cars, its a known issue. Full Blown just released a huge radiator to help the autocross community.

It could be blowby going back into your PCV line if it is hard track time. This is also assuming you dont have a leak.

Make sure you are checking oil at same temps. After you do oil swap, check at certain temp. At track check oil at same temps.

As a general rule most cars operate best when oil temp is 230F or less on the track. Perrin did testing to show the ECU cuts timing when oil gets past 221F.

The issue is two fold, once your engine oil breaks that threshold, it will not stop climbing. No amount of load reduction will drop those temps until you shut down the engine.

Second issue is coolant, as the stock radiator is small it heat soaks fast. As your oil temp climbs your coolant temps will start to climb as well. Once they starting hitting the 220 range the cooling system is maxed out and your oil temps will continue to climb.

Thats stock threshold from my testing. What I can't tell you is how hot is too hot.
I would say if your coolant is cycling from 212-220F and your oil temps have exceeded 240F its time to back off and install at the very least an oil cooler.

I will check my oil level. I did 6 sessions on track at Thundehill a couple weeks ago, two at "flat out" pace and the other 4 in driving school (slower pace)....I just changed the oil right before, so it will be interesting to see the level.

It was 108F at Thunderhill....my water temp gauge never waivered...at all..it was perfect the whole time....it did make me wonder what the oil temps would be....but even 240f isn't bad...but pulling timing above 221F seems excessive for me since its running synthetic oil.....in my Porsche racer I have seen 300F in endurance racing for extended periods....yes the car was nearly overheating, but the oil analysis came back perfect...BUT that was Amsoil 15-50 racing oil...rated for 150C or 312F...