Hi Sam, re oils, my TSI Jetta will run oil temp of 120c just cruising down the highway, 110-114 sitting in traffic. Was up to 125c in summer. I saw a mechanic about my concerns and he checked it out and found that to be quite normal/no issue. My concern was oil breaking down at such temps, so he checked with Castrol about boiling temps for the VW spec stuff, which is rated to ~148 degrees. That gives me piece of mind to not be too bothered about using thicker oils for high temp applications and will run the spec'd stuff.

And given the rate the TSI's drink oil, it's almost always got new oil in it anyway, lol