Fuel efficiency of airplanes

I tend to think of efficiency in monetary terms, i.e. not only how fast the airplane goes on how much gas, but how much did it cost to buy and how much does it take to maintain it. Here I think some of the experimental are real winners, you can get a Vari Eze for not that much money and go fast on little gas. I also think about maintenance costs. My Mooney is complex, so maintenance costs will be higher. But its systems are archaic, simple and not prone to breaking, so costs are somewhat lower. Of course, the other variable is how much you can carry. There are experimentals that can blow the doors off my Mooney in terms of speed, mpg, and acquisition cost. But they can't carry what my Mooney does, and like @William Pete Hodges my wife packs lots of stuff. Sometimes I do too. I don't think I could camp for a week comfortably with what fits in the back of an Experimental. I don't think I could take Mrs. Steingar anywhere for more than a weekend with that kind of space.

So it is a complex calculation.
 
As mentioned, you have to include the value of your time. Panama City to Chicago is about a 16 hour drive (my solo record is about 14 hours). When making the trip with the wife and son, we made it a two day trip. In the 182-RG, it was 5 hours. Because my wife had a 2-1/2 hour rule, we always stopped about halfway. So that made it a 6 hours trip. Airports at each end were less than 20 minutes from our origination/destination so call the total trip 7 hours.

So just counting actual travel time it was 9 hours that was not spent traveling. Add in the overnight and it's closer to 20 hours. That right there makes the reduced fuel economy worth it to me.

Once the Velocity was flying, that 5 hour flight became a 3.7 hour flight (at 15MPG).

And with the 182-RG, we could usually match Delta in door-to-door time (post 9/11). With the Velocity, we beat it easily.
 
I still don’t get why people try to use MPG for an airplane. A good tailwind will drastically increase your MPG where as a strong headwind will diminish MPG numbers.

Because people pay extra for a hybrid or an EV and then smugly hoot at others on the strength of their virtuous MPG or MPGe numbers.

I like this blog post as it offers a counter-hoot to those righteously indignant.

The counter-counter-hoot, of course, will mention that while a car's GVWR likely implies a 1,000# useful load, there are people more than happy to load theirs up and it will still drive, thus quadrupling their effective useful load :D

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And Africa/Asia laugh at us all

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A Lancair doesn’t meet FAA standards for a production airplane.

You're correct. Built by a reasonably competent homebuilder, it exceeds them!

Using TAS is probably a better way to compute a plane's mpg, as it takes headwinds/tailwinds out of the equation.
 
You're correct. Built by a reasonably competent homebuilder, it exceeds them!

Using TAS is probably a better way to compute a plane's mpg, as it takes headwinds/tailwinds out of the equation.
The design fails FAA standards, the builder cannot change that If he follows the kit plans.
 
The same is true with cars, but the winds don't have as much of an impact. But a headwind will lower your MPG and a tailwind will raise it because your RPMs will change. Plus, if you're following a truck, you'll get a big boost...I once drafted a truck in my beetle and made it nearly 400 miles on a 10 gallon tank of gas.

But we still state a single number for MPG for cars.

Wait, are you saying that in a car, while maintaining the same speed, that your RPM's will change when going from calm conditions to a headwind? Your RPM's go up when driving into a headwind?
 
There's one rather serious flaw in your comparison here, at least when comparing GA flying to driving, and that it's very rarely that either your departure point or your destination is an airport, and practically never that both are.

...

Most pilots fly because they enjoy it, not for any practical reason. There are certainly people who can get some utility out of flying light GA, but there aren't all that many.

Depends upon distance, but yes, flying private is rarely practical and generally it costs more.

Now, when the kids were in middle school and high school and four of us were going that wasn't always true. We took trips that were quicker and cheaper than the airlines; we weren't burning 1.5-2 hours at Hartsfield standing in one line or another. Now that the kids have graduated college and are out working it's just my wife and I, so it's two people versus four.

We flew private to Key West for their spring break one year, it was cheaper than four seats on Delta, we got to stop in Sarasota on the way home, where my MIL lived. So, my wife got to have lunch and spend the afternoon with her mother. My MIL got to see two of her grand kids. We've did similar a few times when they were younger and we'd do a few days on Amelia Island then a few days at Sarasota seeing my MIL & FIL for the kids' spring break.

We did a trip to Disney World. Four of us flew private. The oldest kid (out of college and working) flew on Delta, and we picked her up at Orlando. After a few days at Disney we dropped her back off at Orlando to go back to Atlanta, to get back to work, and we went to Kissimmee, hopped in the plane and flew to Fort Lauderdale for a few days. On the way home we swung across the state to visit my MIL in Sarasota again. It's that sort of thing that really makes GA nice. All of our flying time on that trip was about the time it would have taken us to drive from Atlanta to Disney. Just there, not there and back. We got so much more time than if we drove, and we couldn't have done that trip via commercial flights, at least not realistically.

We went to a niece's college graduation for the day. One kid was living in Lexington; going to UK and working there too. She wanted to go too. Hey, Lexington is mostly on the way from Atlanta to the Champaign-Urbana. So, we picked her up on the way, and dropped her off on the way home. Yeah, 1,000 nm round trip in one day to see a niece that we hadn't gotten to see much. That was in a Baron B58, so we we moving along pretty well.

The two younger kids were in SEC schools that played each other in football. We'd fly to the kid from the away team, fly her to the other college town for the weekend. The four of us got to hang out together for the weekend. My parents were in Cincinnati, for a conference, once or twice when we were meeting at Lexington, so they drove down for the weekend. It was great having all six of us together.

The first year our middle daughter was at UK my wife was wigging out about Parents Weekend because she had a conference in Savannah that started Sunday night / Monday morning on the same weekend. She really wanted to go to Parents Weekend, but also needed to get to the conference. I told her, "I'll drop you off. Savannah is just a short way away by air. You can ride home with one of your co-workers, or worst case I'll go pick you up." She got a ride home with a co-worker. That conference lined up with UK's Parents Weekend for 3 years and I dropped her off each time; twice at Savannah and once at Jekyll Island. Easy-peasy, lemon squeezy. :cool:

COVID hit and completely ruined plans for everyone; along with the deaths and illnesses. We had planned a big European trip and even had tickets to the main court at Roland Garros; my wife's favorite tennis player is Rafa Nadal. Plans gone. :( We also planned to fly up to the northeast and see horse racing at Saratoga with some of my family, visit family and friends up in the northeast. Not happening. :( Last year was our 25th anniversary. So, for our 25th anniversary we flew to Louisville, then Memphis, then Nashville and back home to Atlanta. My wife had wanted to visit all of those cities. So we did them all in one week. We had a good time, even with the COVID restrictions. No way to do that any other way. Not without spending less of it touring and more of it either driving or sitting in airports.

So, yes, it's not cheap. It's not even all that much faster at times. But not only is it fun it's also the best way to do some trips. And no, those are not the only trips we did that were not as doable any other way. That's just a few of them. Like going to a college football bowl game, for the day, and having breakfast and dinner at home. Yeah, we did that too. :cool: :D
 
Wait, are you saying that in a car, while maintaining the same speed, that your RPM's will change when going from calm conditions to a headwind? Your RPM's go up when driving into a headwind?

Maybe he drives a CVT? Or one of those annoying 9 gear automatics that will hunt across its 3-4 overdrive gears?
 
Something about how it was written seemed like it was a more passive effect of winds rather than the driver changing gears.. But could be just the way I read it.

Driving a 4cyl Wrangler with a soft top into a 30mph wind vs with it will show the effect of RPM and vehicle speed I think was trying to be originally conveyed.
 
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