I'm trying to think and nothing happens...

[GrySql]

Okay you math wizards, I have a few questions that somehow gets me dizzy when I try to think about them.

The computer in the FFH calculates the average mileage. Fuelly and the FFH computer are pretty close for mpg's.

 

Questions:

1. What if you move your car into the driveway once a day (25'), and move it back into the garage later, once every day. What effect will that have on your overall mpg's?

2. Does the computer use the calculation if you drive your car 25', say from garage to driveway, and enter that data to your overall mileage?

3. What if you idle the car for 5 minutes, the ICE starts and at shutdown you get a mpg reading for that 5 minutes, is that added to your overall mileage?

4. What if the ambient temp is very cold and the ICE starts every time and you get a very low mpg reading for that 25' move?

5. Will frequent small moves and short trips destroy your overall average mpg's?

 

 

[acdii]

Yes to all. Any time the ICE runs it affects overall MPG. Fuel burned whether sitting still or moving 80 MPH is considered in the calculations. If moving the car the short distance has no ICE involvement, then it also has no affect on the calculations due to the short amount of distance driven, but do it with the ICE on, then it has burned some fuel and is added to the equation regardless of how far it went.

 

 

I probably confused you more.

[GrySql]

So, every time I move my car and the ICE runs, the mpg for that move is integrated into my overall Average mpg's.

Hypothetically:

The 25' moves may show as very low mpg, like 3mpg, which goes against the 44mpg that I got traveling 50 miles earlier in the day.

Meaning, 44 divided by 3 equals a grand total for the day of 14.66mpg even though I moved 25' in the one case and drove 50 miles in the other - right?

I'm getting dizzy again....

Edited June 4, 2013 by GrySql

[Guardian_Bob]

So, every time I move my car and the ICE runs, the mpg for that move is integrated into my overall Average mpg's.

Hypothetically:

The 25' moves may show as very low mpg, like 3mpg, which goes against the 44mpg that I got traveling 50 miles earlier in the day.

Meaning, 44 divided by 3 equals a grand total for the day of 14.66mpg even though I moved 25' in the one case and drove 50 miles in the other - right?

I'm getting dizzy again....

 

Not quite, your 3 MPG will be scaled with respect to the distance you went. (The computer will keep track of the gallons used while sitting still and update appropriately when you actually move a fraction of a mile.) Think of it like weighted grades. If one test is weighted 1% but you get a 0, it means the best you can get is a 99% in the class. If on the other hand it is weighed 75% of your total grade, you're, well, hosed.

 

The short distances and long distances are weighted such that you continue to get an accurate number overall.

[GrySql]

 

Not quite, your 3 MPG will be scaled with respect to the distance you went. (The computer will keep track of the gallons used while sitting still and update appropriately when you actually move a fraction of a mile.) Think of it like weighted grades. If one test is weighted 1% but you get a 0, it means the best you can get is a 99% in the class. If on the other hand it is weighed 75% of your total grade, you're, well, hosed.

 

The short distances and long distances are weighted such that you continue to get an accurate number overall.

LOL, I've been hosed before....

 

Moving 25' is too insignificant a number to be used in the average fuel use calculation?

If I move the car in and out of the garage 30 times a month (with ICE running) it will not affect my overall mpg number because the computer is using the miles driven and gallons used as part of the algorithm - yes?

[Guardian_Bob]

LOL, I've been hosed before....

 

Moving 25' is too insignificant a number to be used in the average fuel use calculation?

If I move the car in and out of the garage 30 times a month (with ICE running) it will not affect my overall mpg number because the computer is using the miles driven and gallons used as part of the algorithm - yes?

 

Basically yes. It will keep track of the movement but it will be such a small portion of the whole, you won't really see it.

 

Oh and note, it is still part of the average function, but like I said scaled.

 

So you might get 3 mpg, but you multiply that by the number of miles (0.0001) add it to your normal number (10 miles @ 40 mpg) and you get 400.0003/10.0001 or approximately 40 MPG (rounding).

Edited June 4, 2013 by Guardian_Bob

[GrySql]

 

Basically yes. It will keep track of the movement but it will be such a small portion of the whole, you won't really see it.

 

Oh and note, it is still part of the average function, but like I said scaled.

 

So you might get 3 mpg, but you multiply that by the number of miles (0.0001) add it to your normal number (10 miles @ 40 mpg) and you get 400.0003/10.0001 or approximately 40 MPG (rounding).

Thank you for the helpful explanation.

[dalesky]

Yes to all. Any time the ICE runs it affects overall MPG. Fuel burned whether sitting still or moving 80 MPH is considered in the calculations. If moving the car the short distance has no ICE involvement, then it also has no affect on the calculations due to the short amount of distance driven, but do it with the ICE on, then it has burned some fuel and is added to the equation regardless of how far it went.

 

 

I probably confused you more.

Confused GrySql more? not likely! HAHA

[hermans]

I love the title of this thread. That happens to me all the time.

Edited June 4, 2013 by hermans

[terryb]

I love the title of this thread. That happens to me all the time.

I've decided that the smoke coming out of my ears is from the dust and cobwebs in the power supplies burning off rather than proof of any productive thought output.

[CombsAuthor]

Hey GrySql, I think I have the solution to your problem: Keep your beautiful car in the garage ;-)

[GrySql]

Hey GrySql, I think I have the solution to your problem: Keep your beautiful car in the garage ;-)

Not.. :)

My real problem is that I wash it too often so it stays beautiful!

 

( Edit: It has 8700 miles on it since 12/12/12)

 

Edited June 5, 2013 by GrySql

[hybridbear]

The car calculates MPG based on miles divided by fuel consumed. Anytime you move the car 25 the computer is counting that distance, even though it is small enough to not make your odometer even change 1/10 of a mile. It also measures the gasoline going in to the car at a much finer level of detail than the published hundredths of a gallon that we can see on the trip meters. This is why you can do the math yourself off the trip meter screen of miles divided by gallons and get a different result that the trip meter MPG. For example, 562.5 miles and 10.61 gallons displayed calculates to 53.016 MPG which should display 53.0. But the car might actually display 52.9 which makes you wonder why. The reason is because the car does its math based on more decimal places than displayed and does not round. Thus the 10.61 gallons displayed could be 10.619 gallons used. If you divided 562.5 miles by 10.619 you get 52.971 MPG which the screen would show as 52.9 MPG. Because the car does its math based on more decimal places than displayed the car display is more accurate, aside from the lack of rounding.

 

Hope this helps.

Edited June 5, 2013 by hybridbear

[acdii]

Not.. :)

My real problem is that I wash it too often so it stays beautiful!

 

( Edit: It has 8700 miles on it since 12/12/12)

 

Needs a Spoiler, but LOVE those wheels!