KRviator
Well Known Member
I got bored today and got to thinking what is the best speed to fly in my -9 for the least amount of fuel used, which is commonly known as Carson's speed. Fortunately, I fly (or at least, will very soon fly) an RV-9A, for which CAFE performance data is readily available, via their APR flight testing.
The EAA reports Carson's speed is 1.316x the best glide (best L/D) speed, which CAFE measured as 95 MPH for the RV-9A.
Then I got thinking that maybe other RVators could benefit from having their efficiency data in one place, so I did a little digging and came up with the following numbers. Glide speed has been sourced from, in order of preference: Factory data (in the case of the RV12 for example) CAFE APR's where available, finally, averaged from Builder's POH's reports of their phase 1 test results, with the references provided alongside.
So, for the various RV models, we have the theoretical best MPG speeds as follows, normalized to SMPH:
RV-1:
RV-3: 110.5 SMPH - (Avg of 73 KIAS - N223RL POH, only one so far!)
RV-4: 111.1 SMPH - (Avg of 71 KIAS N359DM POH, 82 MPH - C-GFEW POH, 80KIAS - N41RV POH)
RV-6: 139.5 SMPH - CAFE RV-6 APR
RV-7: 120.1 SMPH - (Avg of 90MPH - N2447A POH, 78KIAS - N447RV POH, 85KIAS - HB-YMT AFM, 78KIAS N585RV POH)
RV-8: 140.5 SMPH - CAFE RV-8A APR
RV-9: 125.0 SMPH - CAFE RV-9A APR
RV-10: 131.2 SMPH - (Avg of 80KIAS- N423CF POH, 90KIAS - N961M POH, 90KIAS - N42BU POH)
RV-11: - I'll ask Van when he finishes it. But how do you measure "fuel"?!?
RV-12: 95.4 SMPH - Vans Factory POH. Can't beat that!
RV-13: Classified - Believed to be in excess of 760 SMPH. If I ever feel the need to break into Area 51, I'll update this one!
RV-14: To be added "soon".
Now, these are not meant to be definitive, and may well vary with individual aircraft - look at the variation in best glide speed and reported glide ratio's for the "same" aircraft, but should be enough to get you in the ballpark for your own testing, if you're that way inclined.
Also, bear in mind best glide speed varies with weight though ratio will remain constant, so variation in test conditions among the various owner's will distort the data somewhat, hence using average values.
Finally, don't blame me if you run out of fuel using these numbers to attempt a Hawaii-LAX flight, it's worth what you paid for it!
The EAA reports Carson's speed is 1.316x the best glide (best L/D) speed, which CAFE measured as 95 MPH for the RV-9A.
Then I got thinking that maybe other RVators could benefit from having their efficiency data in one place, so I did a little digging and came up with the following numbers. Glide speed has been sourced from, in order of preference: Factory data (in the case of the RV12 for example) CAFE APR's where available, finally, averaged from Builder's POH's reports of their phase 1 test results, with the references provided alongside.
So, for the various RV models, we have the theoretical best MPG speeds as follows, normalized to SMPH:
RV-1:
RV-3: 110.5 SMPH - (Avg of 73 KIAS - N223RL POH, only one so far!)
RV-4: 111.1 SMPH - (Avg of 71 KIAS N359DM POH, 82 MPH - C-GFEW POH, 80KIAS - N41RV POH)
RV-6: 139.5 SMPH - CAFE RV-6 APR
RV-7: 120.1 SMPH - (Avg of 90MPH - N2447A POH, 78KIAS - N447RV POH, 85KIAS - HB-YMT AFM, 78KIAS N585RV POH)
RV-8: 140.5 SMPH - CAFE RV-8A APR
RV-9: 125.0 SMPH - CAFE RV-9A APR
RV-10: 131.2 SMPH - (Avg of 80KIAS- N423CF POH, 90KIAS - N961M POH, 90KIAS - N42BU POH)
RV-11: - I'll ask Van when he finishes it. But how do you measure "fuel"?!?
RV-12: 95.4 SMPH - Vans Factory POH. Can't beat that!
RV-13: Classified - Believed to be in excess of 760 SMPH. If I ever feel the need to break into Area 51, I'll update this one!
RV-14: To be added "soon".
Now, these are not meant to be definitive, and may well vary with individual aircraft - look at the variation in best glide speed and reported glide ratio's for the "same" aircraft, but should be enough to get you in the ballpark for your own testing, if you're that way inclined.
Also, bear in mind best glide speed varies with weight though ratio will remain constant, so variation in test conditions among the various owner's will distort the data somewhat, hence using average values.
Finally, don't blame me if you run out of fuel using these numbers to attempt a Hawaii-LAX flight, it's worth what you paid for it!
Last edited: