railgun
03-05-2008, 11:24 PM
This topic will not revolve around oil grades/weights, but rather the operating temps. A slight discussion of dino vs synth may evolve around it, but the overall goal is to gain insight on recommended oil temps, why, and theories to support or debunk that previous why.
So scotty305 has the big fat cooling thread, and I noticed the recommended operating oil temp of 195-230. I have a 335i which has, typically, a minimum oil temp of 230, in warmer days, it's about 240. One track day had it sitting at about 290. I had always been under the impression that it was way too hot (not including the track day...duh, that's hot :) ). Granted, it's a synthetic, but cooler oil is better right?
I had been meaning to talk to the folks at Mobil, or Penzoil, or whoever about this, but haven't gotten around to it yet. But someone had brought up an interesting point regarding temps...
Oil is a lot more resilient that I think we give it credit for. I think it's safe to say that we won't let our motors get into a situation where we hit 300 degree oil temps. But the point that was brought up revolved around getting the oil hot enough to vaporize any moisture/impurities, which is the overall cause of breakdown. At least, over time. That said, at LEAST 212 degrees should be hit to keep any moisture (water) from being introduced and let it be ingested by the motor instead.
Here's where the tricky part comes in. With the massive cooling requirements of the rotary, and the extra part that oil seems to play here, does this theory hold any weight? I by no means am an expert in this field, but the logic is sound. If we were able to maintain a healthy, and constant 225 degree temp, why would we not want to? What disadvantages are there by doing so?
So scotty305 has the big fat cooling thread, and I noticed the recommended operating oil temp of 195-230. I have a 335i which has, typically, a minimum oil temp of 230, in warmer days, it's about 240. One track day had it sitting at about 290. I had always been under the impression that it was way too hot (not including the track day...duh, that's hot :) ). Granted, it's a synthetic, but cooler oil is better right?
I had been meaning to talk to the folks at Mobil, or Penzoil, or whoever about this, but haven't gotten around to it yet. But someone had brought up an interesting point regarding temps...
Oil is a lot more resilient that I think we give it credit for. I think it's safe to say that we won't let our motors get into a situation where we hit 300 degree oil temps. But the point that was brought up revolved around getting the oil hot enough to vaporize any moisture/impurities, which is the overall cause of breakdown. At least, over time. That said, at LEAST 212 degrees should be hit to keep any moisture (water) from being introduced and let it be ingested by the motor instead.
Here's where the tricky part comes in. With the massive cooling requirements of the rotary, and the extra part that oil seems to play here, does this theory hold any weight? I by no means am an expert in this field, but the logic is sound. If we were able to maintain a healthy, and constant 225 degree temp, why would we not want to? What disadvantages are there by doing so?