Playing Tanker

Ironflight · #1 06-10-2009, 11:22 AM

We don?t have fuel at the airpark where we live, so one of the realities of our flying lives is to pick up fuel at neighboring airports in a smart fashion. For instance, local flying hops are sometimes planned to hit a cheap fuel stop on the way home. Other times, we know a trip is coming up, and if it is going to be a long day (and we don?t want a fuel stop in the first few miles) we want to make sure we end up at home with nearly full tanks. At the same time, I am the son of a depression-era parents, and hate paying a penny more than I have to when buying anything ? including Avgas, which we tend to use at a prodigious rate (lots of flying hours?)! As a result, I am frequently asking the question, ?where is the most sensible place to buy fuel today??

This seems like a simple matter ? fly to the nearest airport for gas, or look at Airnav for the cheapest price ? right? Well?maybe. The nearest airport with fuel is 4 miles away, but is generally a dollar a gallon higher than the place 30 miles away. If I am going to go flying ANYWAY, doesn?t it mosey on over to the cheap place and mosey on back? While much of the time, it doesn?t make a real difference (we all know it doesn?t pay to drive across town to save a few cents per gallon, but we hate paying the higher prices!), sometimes, it sure can. The real problem I have is in completely and accurately describing the ?problem? I am trying to solve. Cheapest overall? Most fuel? Best price per gallon based on the amount you have when you get home? The engineer in me wants to quantify everything, but if you can?t accurately describe the question, the answer will be ambiguous.

In an attempt to try and at least clarify the problem, I built a little spreadsheet that considers a flight to go and get 20 gallons of gas. It considers the price at each airport, the distance to the airport, and a set of variables such as fuel burn and ground speed that are held constant for each case. I added up the fuel for the round trip plus the 20 gallons, and produced a ?total gallon? column. Another column is ?Fuel remaining when you Get Home? (of course that is always going to sort with the closest airport at the top). I found that if there was enough difference in fuel prices in the local area, the total fill up cost can vary significantly from the ?nearest to closest? sort. This of course, was just a quick and dirty look at the problem ? I?d be interested to see if anyone else has thoughts on this ?rainy day? problem?.

Geico266 · #2 06-10-2009, 11:32 AM

You can sure tell when the space shuttle is on the ground.

Problem solved...... and you are saving about $1 / gallon by topping off your tanks with 92 Octane mogas. Buy 100ll when you can and where you stop, top the tanks off when you get home. I've pumped over 5,000 gallon of mogas though this 100 gallon tank.

Filling up at your home airport also offers less wear and tear on the plane.

Jimd · #3 06-10-2009, 11:53 AM

Paul,

I do much the same thing as you with a trip out for cheap fuel. When I know I have a trip coming up I siphon off 6gal out of each tank using a clear vinyl hose. I fill the hose using the quick drain and then poke one end into the tank and the other into the gas jug on the floor in front of the wing. I then fly oout for my little attitude flight, stop for cheap fuel on the way home and then top off with the 12gal in the jugs. I only use about 3 gal to get home from the fuel stop so I usually have enough fuel left over for a near fill from a short last leg home.

(I never buy fuel at my home airport because they **** and moan about driving the truck up to my hanger for "only" 10 gallons, all the while they are one of the most expensive places in the state to buy 100LL. I save 1.70/g by going elsewhere, I get to fill it myself and I ike to fly!

frankh · #4 06-10-2009, 01:16 PM

like when ethanol free mogas (5 min flight away) is about same price as the watered down stuff in town..Then

I found that 4*5 gallon gas cans fit rather nicely in the bagage area...If I'm by myself I can fit another 2 on the PX seat.

I tie a strap on the on them to stop them sliding around.

Frank

N523RV · #5 06-10-2009, 01:23 PM

Willing to share your spreadsheet so we dont' have to recreate the wheel? I'd even post it on my web server for others to d/l...

Matthew
matthew@n523rv.com

Quote:

Originally Posted by Ironflight

We don?t have fuel at the airpark where we live, so one of the realities of our flying lives is to pick up fuel at neighboring airports in a smart fashion. For instance, local flying hops are sometimes planned to hit a cheap fuel stop on the way home. Other times, we know a trip is coming up, and if it is going to be a long day (and we don?t want a fuel stop in the first few miles) we want to make sure we end up at home with nearly full tanks. At the same time, I am the son of a depression-era parents, and hate paying a penny more than I have to when buying anything ? including Avgas, which we tend to use at a prodigious rate (lots of flying hours?)! As a result, I am frequently asking the question, ?where is the most sensible place to buy fuel today??

This seems like a simple matter ? fly to the nearest airport for gas, or look at Airnav for the cheapest price ? right? Well?maybe. The nearest airport with fuel is 4 miles away, but is generally a dollar a gallon higher than the place 30 miles away. If I am going to go flying ANYWAY, doesn?t it mosey on over to the cheap place and mosey on back? While much of the time, it doesn?t make a real difference (we all know it doesn?t pay to drive across town to save a few cents per gallon, but we hate paying the higher prices!), sometimes, it sure can. The real problem I have is in completely and accurately describing the ?problem? I am trying to solve. Cheapest overall? Most fuel? Best price per gallon based on the amount you have when you get home? The engineer in me wants to quantify everything, but if you can?t accurately describe the question, the answer will be ambiguous.

In an attempt to try and at least clarify the problem, I built a little spreadsheet that considers a flight to go and get 20 gallons of gas. It considers the price at each airport, the distance to the airport, and a set of variables such as fuel burn and ground speed that are held constant for each case. I added up the fuel for the round trip plus the 20 gallons, and produced a ?total gallon? column. Another column is ?Fuel remaining when you Get Home? (of course that is always going to sort with the closest airport at the top). I found that if there was enough difference in fuel prices in the local area, the total fill up cost can vary significantly from the ?nearest to closest? sort. This of course, was just a quick and dirty look at the problem ? I?d be interested to see if anyone else has thoughts on this ?rainy day? problem?.

Gsuit · #6 06-10-2009, 02:17 PM

I haven't created a cool spreadsheet but then again I do my 'tanker' run to just one airport. T90 (on Paul's list). I calculate that I save $30-$40 on average over my homebase BMT to fly the 12 minute hop and fill up in my -7. I don't include wear and tear on the plane because I wouldn't need the gas if I wasn't going flying anyway

Ironflight · #7 06-10-2009, 05:03 PM

Quote:

Originally Posted by Gsuit

I haven't created a cool spreadsheet but then again I do my 'tanker' run to just one airport. T90 (on Paul's list). I calculate that I save $30-$40 on average over my homebase BMT to fly the 12 minute hop and fill up in my -7. I don't include wear and tear on the plane because I wouldn't need the gas if I wasn't going flying anyway

Watch out - T90 just got expensive!

I flew across the bay to Anahuac this morning (has been $2.65/gallon), and while I was on base, the Unicom lady told me the fuel pump was broken. i asked if Winnie was up (she.the County runs them both), and she said "yes", so I thanked her and landed there to fill up. After filling, the receipt said it was $3.65/gallon!

I should have gone to Liberty....(And this was what reminded me to dig out the spreadsheet and start this thread...

)

Paul

Ironflight · #8 06-10-2009, 05:03 PM

Quote:

Originally Posted by N523RV

Willing to share your spreadsheet so we dont' have to recreate the wheel? I'd even post it on my web server for others to d/l...

Matthew
matthew@n523rv.com

I'll email it to you Mathew - it's crude, but works.

Paul

N523RV · #9 06-10-2009, 05:13 PM

Here is the file for anyone that would like it.

http://www.n523rv.com/Tanker%20Calculator.xls

Quote:

Originally Posted by Ironflight

I'll email it to you Mathew - it's crude, but works.

Paul

Neal@F14 · #10 06-10-2009, 05:35 PM

When hauling large amounts of mogas around on a trailer or in the back of a pickup truck, better check local laws to make sure you aren't required to have a special expensive type of tank that is DOT-approved for gasoline and possible also a permit or license to haul more than 50 or 100 gallons that is not dispensed directly into a vehicle's fuel tank from the point of sale. Some of the state laws have become quite onerous in recent years. For example, I think it happened in Florida a couple years ago, where some guy got charged with a felony for using an unapproved transfer tank mounted in the bed of his pickup truck for transporting 100+ gallons of gasoline for his boat. The laws often differentiate between diesel transfer tanks and those that are DOT-approved for gasoline, which are much more expensive. Something about diesel being merely a "combustible" liquid whereas gasoline is "flammable" and it's transportation being more tightly regulated.