I did a test with a small rocket and this is what I got: Start stage End Stage: At the start it looks like I only have 1800 delta V available but the actual is at 2200 delta V. Now I'm aware that the 1800 m/s reading is for sea level, but I didn't expect such a large change (~20%) in delta V when only 10000m up and how this will effect rockets on Eve So to measure Delta V I will use the ascent stats to find out the actual delta V, but there is only so much I can burn before I go outside Kerban's gravity and the ascent module turns off (around 8000m/s Delta V)