Baron - 58 vs 58P

[Chimbu chuckles]

Turbonormalised engines shouldn't show a large increase in operating costs because unlike turbocharged engines they are still only getting 29.9in MP but maintain it to a higher critical altitude...instead of 36in MP which really puts extra stress and heat into the cylinders.

Operating in the low to mid teens is good because you will usually be above the weather or on really bad days be able poke around it more easily...diversions off track due weather are likely to be less...and virtually no-one else is operating in that altitude band so you are more likely to get want you want from ATC. The normally aspirated are all below 10, the turboprops are above 20 and the jets are above 30...12-18 is a real quiet bit of sky.