We're supposed to keep a warming up engine *above* 2K? I always thought it was below 2K...what is the sweet spot RPM range for the 2015s? Is an ALH supposed to be kept below or above 2K, as well?
That's just how he chooses to warm his car. Seems sensible to me. I do the same- trying to keep the rpm between 2000-2500 until the needle is at 9 o'clock.
OK, this is how I choose to warm my car up, especially when it's 0F or less outside. My comments apply to cold starts, say 35F or less.
What I see during a cold-start is the turbo boost going as high as 15psi when the coolant temperature is ambient temperature, 0F or less this week. Now the ECU is programmed to start the warm-up mode when the water temp is around 100F, BUT, the oil temperature can be very cold. Yeah, I know we have an oil cooler that uses engine coolant. But the water temp sensor is not at the turbocharger so we have no idea what the oil temperature is at the turbocharger. All we know is that the oil temperature will eventually be the same as the coolant temperature. It can take several minutes for all the oil to reach normal operating temperature when the temp gauge says the engine is fully warmed up.
The context of my post is to keep boost low until the engine has had a chance to warm up, AND the oil. Slightly higher revs during cold starts and during the catalyst warm-up mode lowers the turbo boost a quick 5 PSI. Simple put, the higher engine revs are doing the work so the engine does not need as much turbo boost. That is a lot less stress on the turbocharger. After the coolant temperature has reached something reasonable, say 150F on the Scangauge, NOT the coolant temp gauge on the dash, then I let the revs drop to normal driving, 1300 to 1500 RPM.
Now we get to the coolant temperature on the Scangauge Vs the dash gauge. The dash gauge is highly buffered. It already reads 190F when the Scangauge is reading 145F. Also, during a regen, the Scangauge will read 215F while the dash gauge reads 190F.
As an aside, on my 2014 Passat the dash coolant temp gauge always read 190F, while the Scangauge read at least 210F. During a regen the dash gauge might drift up to 195F to 200F, the Scangauge would read 215F to 225F. On the 2015, the dash gauge reads 190F and the Scangauge read very close at 190F to 195F. Even during regens the 2015 rarely reads over 205F on the Scangauge.
I hope this explains things better.
