So way back when I started playing ksp I remember a wiki article on what your max velocity should be at various kerbin altitudes. It went something like 110m/s for 1000m, 120m/s for 2000m, 160m/s for 5000m, 260m/s for 10000. I remember testing full burns vs controlled burns, and noticed that it is more efficient to follow this chart. Thing is, I now restarted the game, and am experimenting with the basic solid boosters. I am finding that it is less efficient to lower the thrust limiter on the bacc thumper booster. At 100% thrust, it gets me a 42 second burn, to an altitude of about 296 000m. If I do a 75% thrust limit burn, I get ~56 second burn, altitude of 267 000m. Can anyone explain why the 75% doesn't get me higher? I'm sure it's something obvious I'm overlooking. The pattern above is also true the more you lower the thrust ( I tried it at 50% thrust as well)