For some reason the last few laps (and lap 6 in particular) felt better than that... but at least it's a 1:39. And somehow lap 2 was 16.0, that surprised me a bunch. It's still my weakest 6-lap time, but this is the most painful track, so that's probably excusable...

Laps: 18.0 - 16.0 - 16.4 - 16.5 - 16.3 - 16.5 (huh?!) Played in DOSBox 0.74, max cycles.