456GT engine running cold

Hi all,
I took my 1997 456 out for its first big drive after purchasing it earlier this year. It was basically just a straight dash from Belgium to Bavaria. The most impressive finding: average fuel consumption of 13.8 l/100km. Didn’t know I bought an economy car…

here’s one thing I noticed though: when in city traffic, the engine is warming up nicely, water and oil temp needle are sitting closely around the middle. Oil pressure is at 45 degrees to the left when at standstill and dead snack in the middle when driving.

As soon as I got to the country roads are an autobahn, temps dropped immediately to roughly 50-60 degrees on both ends. At the same time, the oil pressure went to the right of the middle, especially during driving. The car just got back from a major service at a Ferrari specialist here in Brussels. They didn’t indicate any issues. The car also didn’t showcase any warning lamp of sorts during the whole drive. One thing I noticed is they definitely overfilled the engine oil, as the mark on the dip stick is slightly (maybe 1-2mm) above the max line.

I also noticed a very faint high pitched noise when I got to around 200 km/h, and I’m wondering if it’s coming from the belt, as the viscosity of the oil might be too dense due to the low temp. I think I can rule out a faulty reading as all three relevant indicators (oil pressure, cooling temp, oil temp) are a part of this. Did anyone run into the same issue before?