Lowest fuel flow?

[mgomez]

Hi,

I've heard stories of 3.5 gph fuel flows in level flight in some RVs. It makes sense...comes out to about 40 HP required, which is consistent with the rate of climb numbers that are published.

What numbers have you guys seen in flight for fuel flow? And what airspeed resulted (and was it TAS or IAS?)

Thanks,
Martin

[Rick6a]

Originally Posted by mgomez

Hi,

I've heard stories of 3.5 gph fuel flows in level flight in some RVs. It makes sense...comes out to about 40 HP required, which is consistent with the rate of climb numbers that are published.

What numbers have you guys seen in flight for fuel flow? And what airspeed resulted (and was it TAS or IAS?)

Thanks,
Martin

I recently enjoyed a perspective most people never experience. I flew alongside my other airplane, a C-150 being flown by a friend. As I throttled back to maintain formation, the fuel flow shown on the VM-1000 danced between 3.1 and 3.5 GPH. Wide open, I've seen fuel flows of 11.5 GPH.

Rick Galati RV-6A "Darla" 0-320 D1A Lasar equipped

[Tandem46]

Martin,
I posted following last spring:

We all know how fast these wonderful machines can go, but they make wonderful slow speeders too, at least with regards to fuel burn. Today, while putting around the area in my RV-7 equipped with an IO-360 with LSE and one mag, I pulled the throttle back to 15-16 inches, prop at 2400rpm, and leaned to the lean side of peak (LOP) at 4500'. I was indicating 120kts, my Dynon was giving me a true airspeed of 130kts, and my fuel burn was barely 5.5gph. Pretty amazing.

Tobin

[mgomez]

Originally Posted by Rick6a

As I throttled back to maintain formation, the fuel flow shown on the VM-1000 danced between 3.1 and 3.5 GPH. Wide open, I've seen fuel flows of 11.5 GPH.

Rick Galati RV-6A "Darla" 0-320 D1A Lasar equipped

Thanks! What was the TAS? Or IAS and altitude? Of course, you were probably looking outside

[Rick6a]

Originally Posted by mgomez

Thanks! What was the TAS? Or IAS and altitude? Of course, you were probably looking outside

Search me. We were flying at 2000' but beyond that, I was mostly fixated on protecting all that airborne equity! Now here's another recent event and why RV's rule. Keep pounding those rivets RV'ers!......The other day, and I knew that day was eventually coming.........I raced the local V-tail Bonanza based at our small airport. Emboldened by besting a Long EZ awhile back, Randy has always thought of his Bonanza as the fastest airplane based at Greensfield. When he heard me on the radio as I reported entering the pattern, he called, said he was a 5 miles north of the field and if I had time, "Lets do a speed comparison". I said "Be right there" and promptly rolled into a steep 180 for the aerial rendezvous. Shortly we met up, stabilized everything wingtip to wingtip, then we both went to full throttle. Soon, I was pulling away from his bird....decisively. Chagrined, Randy said "What does your GPS groundspeed read?" As matter-of-fact as I muster, I said it was reporting 196MPH. "Hmm," he said. "Mine is reading 181MPH. I guess those RV's are fast" he said. "But Randy" I said, "I'm only running 160HP." "YEA, I KNOW IT," he said.

Rick

[tacchi88]

Sold my Arrow to pay for RV10, but consumption on Sweaty Betty, with IO360 180 hp, was average 8.5 gph, 5000' at 143kts true for cruise. It had LASAR. Without LASAR 10gph, 5000' at 138 true for cruise.