This is from a spreadsheet I made when I got the new propeller. This is the data for the 3-blade prop. With the 4-blade prop the plane became 3 KTAS slower
alt temp rpm FF/MP TAS IAS
9000 -3 2540 13,3 21,5 173 148
9000 -5 2500 13,8 21,6 173 149
9000 -5 2500 13,7 21,5 169 146
9000 -5 2500 13,8 21,5 167 145
And this is a flight a week ago with the 4-blade MT prop:
Alt 7500 0 C 2540rpm FF13,9 MP 22,3 TAS 168 IAS 149
Show us your perf table for 8000 ’ please.
This is the ROP table. I fly LOP only, my average with the 3-blade prop was about 168-170 KTAS @ 11.000 and 12.8 GPH
How do you account for your +10 Knots numbers Vs book ?
I don’t know, but these are all numbers I have pictures of from my PFD. Ask other SR22 pilots here, they will confirm that these are typical numbers, and mine is not one of the fast ones.
There’s a guy on COPA (a Google manager who’s really into statistics) and he did a very throrough research about the cruise speeds of the SR22. You can google it and read it, Tomas Vykruta is the name. You can download the whole report
Interesting read the report.
Based on it, looks more like a 8 – 10 Knot spread between the G1 & G2 SR22s and 300/350 LC550FGs .
I expect to squeeze out another 2 – 3 knots on mine when I find the time to make some small mods to clean it up abit.
the luxury of retracting gears costs about 10$ per flight hour in scheduled maintenance
That true only if the plane is shagged, neglected, shagged some more, landed in sand (Calvi in Corsica would do nicely), the gear is never lubed so the only time it is serviced is when it almost seizes up and the pilot lands with brown trousers and demands action.
Admittedly the above is a pretty good description of most retractables on the UK rental and even syndicate scene, especially twins…
On my TB20 the gear costs me a few hours extra at the Annual so that’s about GBP 1 per flying hour.
Would be better to have a separate table for LOP.
I have flown in an SR22 (non T), DA42 and a C400 and all of them did exactly the same IAS at the same fuel flow as my TB20: 140kt at 11.5 USG/hr. No free lunch, for a given cockpit volume. The SR22 and the C400 have a slicker airframe but chuck away the whole advantage with the fixed gear. The DA42 does very well given that it is a lot bigger a plane and hauls a second lump under a wing, and it demonstrates that increasing the compression ratio by a factor of about 1.6 (which is what diesel gives you over petrol) improves the SFC b the 0.4th power of the CR, so a 1.6x increase gives you about 25% more power for the same fuel flow.
Peter wrote:
On my TB20 the gear costs me a few hours extra at the Annual so that’s about GBP 1 per flying hour.
Plus a few bob for the pressurized struts and don’t forget the occasional power-pack overhaul and hose replacement 
