Gas Cost Impact on the Family Budget
It was suggested that five dollars a tank is not much extra gas money.  I guess it depends on your budget and perspective.  I thought I would provide this analysis of my gas costs because I have the data while many people may find gathering the data a great annoyance. I actually have my family log all the data (miles driven, gallons of gas put in, cost per gallon, miles per gallon, etc.) on our four cars so I can analyze it.  My dad was an engineer and he had us do this since we first started driving.  His purpose was more to see if a drop in MPG was indicating engine problems, like fouled spark plugs.  I use the data to project next year’s gasoline budget.  I thought you might like to see an example, as shown below.
SUBROUTINE: MILEAGE DRIVEN, GASOLINE USE	 	 	 
AND COST PROJECTOR	 	 	 	 	 
 	 	 	 	$/gal	 	 
 	INPUTS IN YELLOW	 	$2.80 	 	 
 	mi driven	mpg city	gal/year	$/year	$/week	$/mth
Corolla	9,550 	30	318 	$891 	$17 	$74 
Nova	5,547 	24	231 	$648 	$12 	$54 
Echo	4,680 	29	161 	$452 	$8 	$38 
Mazda 3i	3,554 	25	142 	$398 	$7 	$33 
Yearly	23,331 	27	853 	$2,389 	 z	$2,389 
Monthly	1,944 	 z	71 	 z	$199 	$199 
Weekly	449 	 z	16 	 z	$44 	$44 
 z	 z	 z	z 	$2,388 	 	 
 	 	 	 	cross check	 
SUBROUTINE: MILEAGE DRIVEN, GASOLINE USE	 	 	 
AND COST PROJECTOR	 	 	 	 	 
 	 	 	 	$/gal	 	 
 	INPUTS IN YELLOW	 	$3.80 	 	 
 	mi driven	mpg city	gal/year	$/year	$/week	$/mth
Corolla	9,550 	30	318 	$1,210 	$22 	$101 
Nova	5,547 	24	231 	$879 	$16 	$73 
Echo	4,680 	29	161 	$613 	$11 	$51 
Mazda 3i	3,554 	25	142 	$540 	$10 	$45 
Yearly	23,331 	27	853 	$3,242 	 z	$3,242 
Monthly	1,944 	 z	71 	 z	$270 	$270 
Weekly	449 	 z	16 	 z	$60 	$60 
 z	 z	 z	 z	$3,241 	 	 
 	 	 	 	cross check	 
I have got a fairly efficient fleet of vehicles now so if your measured MPG or driving distances are different, your costs will be different.  What these two charts show is that if gas currently at $2.80 a gallon ($2389/yr) were to go back to $3.80 a gallon ($3,242), then I would have to pay an additional $853 dollars a year.  I got rid of a Buick Park Avenue and added a Corolla and a Mazda 3i, so our average fuel economy is pretty good, and the impact is tolerable for us.  The spreadsheet grids, spacing, shading and colors did not transfer into the forum so it is cryptic but the data is all there.  The spreadsheet is pretty simple to set up if you want to see the impact of higher gas costs on your family budget.  I suspect most people are not concerned enough about the gas prices to set a calculator like this up, but maybe it will be useful for a few.  Hope it is interesting to some.