Joe,

The IV is a great traveling machine.  You are, however, correct in your assessment of "just for fun" flying. In that regard you just can't beat the 360.

In my experience operating an IO-550 powered IV, I have found that operating at an IAS in the range that you are considering (150-160 kias) will require a fuel flow of less than 10 gph. The higher altitude you fly the lower the fuel flow and the higher the TAS.  At 14,000 ft, for example, 150 kias will produce around 190 ktas with a fuel flow of less than 9 gph (depending on weight).  This assumes, of course, LOP operation.  Flying slower than these speeds, down to 130 kias or so, would allow squeezing a tiny bit more efficiency out of the IV but it's a fairly broad topped curve at these speeds. Your actual MPG would not be dramatically better and with a headwind might even be worse.

Bill Harrelson
N5ZQ 320 2,150 hrs
N6ZQ  IV  450 hrs





LML,

I've been looking at N301H (IV) as a way to get a bit more space than my 360.  301H is listed on Controller and based in palm beach.  Does anyone have any gouge on this aircraft?

I'm a little concerned that at twice the $ per flight hour I won't take it up as often just for fun.  I'd be interested to hear your thoughts on cruising in a IV at max range and max endurance.  The BSFC of the TSIO-550 is only 5-10% worse than the IO-550 according to Conti.  The cruise speeds ive seen quoted are far from the published L/D MAX ( max range) speed of the IV.  Can anyone comment on operating at a more efficient 150-160kias?

Joe Czabaranek