Oil Pressure.
 

I'm losing a bit of oil pressure after the car runs for awhile, it will only do it after it's been ran for 20 or so minutes of aggressive driving. I have no oil cooler, and wondering if my oil getting to hot could be the problem. I only have a minor oil leak on the front main seal. The car never did it before the turbo, and started it after it was installed.

Oil Pressure at like 6k rpms is around 45, cruising it is around 30-35, and around 15 at idle.

Any ideas?

mine does the same, but i'm n/a. it may just be the oil getting hot, but all the info i could find about oil pressure suggested that these are normal pressures and not to worry.

Ahh, thanks. Every Miata I have driven has had so much more oil pressure than mine so I figured it was a problem.

I'm going to be dropping the money on a FM Oil Cooler in a month or so, so hopefully it will fix it/keep it cool.

At idle after the car is warm my pressure is around 16 PSI with Mobil 1 0w30 Synthetic. I ran 0w20 last winter and idle pressures would drop to 13ish, sometimes 12 ... that made me nervous so I went back to 0w30.

Cold startup with the 0w30 is ~75-85 psi; highway cruise at 3k rpm is around 50-55 psi.

I haven't noticed any oil pressure behavior changes in the 5k miles or so since I put the rotrex on.

People like you is the reason Mazda stopped putting real oil pressure gauges in our cars...

On a more serious note, as long as your oil pressure isn't zero at idle, you're fine. Also, as long as your OPG works similar to your tach, you're fine.

There are 3 possibilities for your oil pump:

1. Your oil pump is getting oil
   If this is the case, stop worrying. Your oil pump will flow a set VOLUME of oil for a given RPM. Your oil pressure may be lower, but oil is flowing just as fast.
   .
2. Your oil pump is getting oil sometimes
   This is an extremely unlikely situation. If this is the case, you will see oil pressure drop under braking, and normal when accelerating/not braking. Also, if this is the case, you're a blundering idiot, and need to check your oil a little more often.
   .
3. Your oil pump is not getting oil
   If this is the case, your oil pressure gauge will show "0" - there will be no question about whether your car is getting oil pressure or not. You'll know.

There is one other option, which doesn't involve the oil pump. A catastrophic failure such as a blown oil line may show a decent drop in oil pressure. If this happens, then:

1. You have bigger problems
   
2. Your oil level will quickly drop such that your oil pump will stop getting oil, and your OPG will soon be registering "0" anyways.