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Ed Anderson wrote:
My best performance with the current 2.85 and 74x88 prop was 200 MPH TAS 12.3 GPH burn rate at 9500 MSL. Pulling back to 10.3 GPH gave 190 MPH TAS. But, I normally cruise at 7.5-8.5 GPH at 140-150 IAS – just too cheap to go anywhere in a big hurry {:>).
How much did you really save? You're burning less fuel, but you're in the air longer.
OK, so I'm bored, with nothing to do but watch progress messages scroll by from my tests. I set up a spreadsheet for some comparative analysis. With a 50mph headwind (when Ed is at his safest), and fuel at $4.96/gal, you'll save $5.61 over a 190 mile trip and be in the cockpit for an extra 45 minutes or so. If that headwind were negative (ie, the evil tailwind), that extra fuel burn will make your trip 6.6 minutes shorter and your wallet $11.88 lighter.
Moral: Relax in the tailwind, but pour it on in a headwind.
I'm attaching the spreadsheet and a screenshot.
snapshot2.png
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