I was curious about using 0W-30 oil in my cruze in the winter, so I sent a email to GM about it. Much to my surprise, I got a phone call, not from a service rep, but from one of the powertrain engineers at GM (!!!) I was dumb and didn't think to write down his name =P. Anyway, my request was in regards to whether 0W-30 can be used in my cruze in the winter, because I was worried about the Turbo, and the owners manual states that 0W-30 may be used in extreme cold temperatures. Which confused me, because it also says that Dexos certified oil must be used for warranty. And all Dexos oil is 5W-30.
Anyway, he told me that he agrees with me, that 0W-30 oil would be better in cold temperatures, but because the no 0W-30 meets Dexos NOACK requirements, I should use 5W-30 to maintain my warranty. He also went into much more detail regarding this, below.
He also told me that in the case of the cruze, they did a lot of research regarding how to keep the turbo bearings safe. Because most people won't treat a turbocharged engine any differently than they would a N/A engine, which means that high-RPMs are entirely likely within the first few minutes of driving.
According to him, the oil pump was designed and programmed to deliver much higher flow than you would otherwise find. He said that the Turbo and lubrication system were specifically designed for this type of use, and though it's still not recommended, 5W-30 should provide sufficient protection down to 50 below, and there will be enough flow to the turbo bearings to prevent any significant wear.
Since I had him on the line, I asked him about hot shutdowns. He told me that, again that was a consideration they had, most people will not know to treat it any differently. So the cooling system is designed to provide coolant flow via natural convection, to keep coolant flow through the turbo water jackets even after the engine is shut down.
Honestly, I was extremely impressed that I would be contacted by someone other than a service rep. And he certainly explained a lot more than would have expected. I thought you all would be very interested in this information.
Anyway, he told me that he agrees with me, that 0W-30 oil would be better in cold temperatures, but because the no 0W-30 meets Dexos NOACK requirements, I should use 5W-30 to maintain my warranty. He also went into much more detail regarding this, below.
He also told me that in the case of the cruze, they did a lot of research regarding how to keep the turbo bearings safe. Because most people won't treat a turbocharged engine any differently than they would a N/A engine, which means that high-RPMs are entirely likely within the first few minutes of driving.
According to him, the oil pump was designed and programmed to deliver much higher flow than you would otherwise find. He said that the Turbo and lubrication system were specifically designed for this type of use, and though it's still not recommended, 5W-30 should provide sufficient protection down to 50 below, and there will be enough flow to the turbo bearings to prevent any significant wear.
Since I had him on the line, I asked him about hot shutdowns. He told me that, again that was a consideration they had, most people will not know to treat it any differently. So the cooling system is designed to provide coolant flow via natural convection, to keep coolant flow through the turbo water jackets even after the engine is shut down.
Honestly, I was extremely impressed that I would be contacted by someone other than a service rep. And he certainly explained a lot more than would have expected. I thought you all would be very interested in this information.
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