those with perrin oil coolers
 

How much oil are you putting in after draining it? 6 or 7 quarts?

I don't have one, but the install instructions say you will need an additional quart.

http://perrinperformance.com/attachment/74777-.pdf

My setup which is custom but effectively the same cooler needed about an additional quart.

I fill my car with 5 quarts instead of what the owners manual suggests which is like 5.5 or something. So I'm guessing 6 quarts with be enough right?

The oil in the cooler will not drain when you drain your oil. Just put in the normal 5ish quarts it takes when doing your oil changes.

This.

The stock motor takes around 5.5qt on a fillup, people say to add another 1qt for an oil cooler.

so 1 out total 6.5qt is only 15% of the total oil. As you keep changing your oil, this 15% will blend in with the new oil, then some of it will get drained out on the next change. Practically speaking, the oil left over on the next change will be less than 15% the oil from the first run.

Overall, I change my oil so much (every 3-4k miles or after a track event) that I will eventually dilute the "old" oil out so it won't harm my motor.

We have to remember, tHere are people in this world who drive their cars and never change the oil and do this for tens of thousands of miles before having major issues.

thanks, was wondering about the oil in the cooler and how i would get that out. So even with the oil cooler you're only putting 5 quarts?

my stock RX8 has dual oil coolers and I had 8 years and 80K miles on it with the engine going strong and I never once worried about the "old" oil that didn't get changed when I did my typical oil change.

Given we are running synthetic oil stock, and your cooling the oil with the cooler, your overall oil mix will be just fine.

7 quarts on my frs with the perrin oil cooler