Jawnathin

Just filled up my car with Amsoil 15W50 in preparation for the warm summer HPDE season. HPDEs allow me to do a warm up lap as needed to get up to temp.

Car is also used for autocrosses. Don't have the luxury of a warm up lap for autocross. Just a long idle then hard driving right away.

What is recommended minimum temp for 100% throttle + max RPM usage with 15w50? Car is a C6Z if it matters.

Thanks.

smellya

I get mine to around 140 before I beat on it...

froggy47

150-180. Just start it up a while b4 your autox runs.

Jawnathin

Thanks. 150F even with 15W50?

I used to wait till 150 for 5W30, I figure 15W50 would need to be a bit warmer.

urtoslo

Make sure your water is up to temp also. Once your water temp comes up to the thermostat opening up, go for it.

froggy47

150 would be my bare min.

With 10w-30 I have got on it hard a bunch of times @ 150 & my Blackstone #'s are excellent. !80 is better.

Jawnathin

Thanks. I will make sure coolant is warm too but that heats up much quicker than oil. Oil is the one I'm usually waiting for.

Thanks, I would use 150F as minimum for 5W30 or 10W30 but given how much thicker 15W50 can be, is 150F still the right guideline? I thought due to the increased viscosity, it would need to be warmer than a thinner do adequate protection.

Would rather spend an extra few minutes warming up the car over damaging something.

Mark2009

I spoke with a Redline tech rep the other day, without reference to any particular oil weight, and he seemed uncomfortable with 170F (which is a temp that I mentioned).

So, given your parameters -- 100% throttle + max RPM w/15W50 -- I would say 200F. According to my rudimentary understanding that is the design temp for the OEM spec oil, BTW. Oil pressure might be a guide (80PSI at 7K RPM is probably too much, but that's a guess).

Keep in mind that the LS7 oil temp sensor in the tank probably gives you a warmer reading than the oil that is being returned from the cooler. That was a question posed by the tech rep as well (location of the oil temp sensor).

I recently changed to Redline 7.5W35 (I'm sure most of you can figure that out ) and noticed the oil pressure is up compared to similar temps with the previous Mobil1 5W30 fill, at least until the oil gets up around 200F (still higher pressure, but not as much).

Jawnathin

Thanks Mark.

I don't have much time with my new oil cooler/radiator, but with the old oil cooler the car will never hit 200F without driving it aggressively. Idling it for 20 minutes might get it to 180F but 200F is impossible. I can get it to 200+F after a good drive but idling will bring it down to 190F.

Interesting that your Redline guy didn't like 170F for 5W30. Id have been pretty happy with those temps. I was thinking that 170F might be the minimum for 15W50, but if he doesn't like it in general, now I'm questioning that temp for a thicker oil.

froggy47

In the typical scenario of how an autox is put on, it's really almost impossible to get most oil, never mind the thicker ones, up to FULL design operating temp.

Idling for a half hour even will probably not do it.

IMO

You might "blend" the weight down to compromise (as mark describes) the two venues.

Sometimes you can have too much cooler for a multi purpose car, hence why I like the cooler in the radiator system.

Jawnathin

Thanks. Agreed. I just switched to the cooler in the radiator combo. Heats up a lot sooner than it did before.

Guess I'll try and get it to 170F before my first run. Hope the new system can get it there quick enough.

roadandtrack

180F minimum. In my C6 Z06 I prefer closer to 200F before WOT or over 5000rpm.

Mark2009

Shouldn't be a problem if you just let it idle with the AC off. My coolant certainly heats up quickly that way, 215 or better (the AC knocks it back down, though, with the fan running... but of course this is with a stock tune).

Jawnathin

Thanks all. I let the car idle for a bit prior to the first run, then once you get going its stays warm. Just wanted to be sure it was warm enough prior to that first run.

170F was my benchmark but it was closer to 180F when it was time to go. Car took it like a champ!