The owners of older (read: high-maintenance) cars often lament over the expense of keeping their vehicles running. My 1978 Ford Mustang II is no exception. Through mustangii.org I found several other owners of similar cars, and found that indeed I was not the only one beating my head against solid object over the occasional dilemma between what I wanted to do, and what the car needed me to do.
One popular quote amongst owners was of what we would do if we had a "cubic yard of cash". I know I have never seen that large a volume of money before. I'm not sure that many people have. Unfortunately, I have no pictures of that much money, because I certainly don't have it right now. This page is devoted to some simple calculations I have done to calculate how much money would constitute a "cubic yard of cash".
Of course, it would seem that the US Mint would be a good place to start looking for information on US currency. However, it appears that their website focuses mostly on coins. One could also try the Federal Reserve (check your bills, they actually printed them), though that website is mostly concerned with fiscal policy and other such exciting governmental functions.
Finally, I found some good information at The Bureau of Printing and Engraving about the dimensions of US currency. They list US bills as "2.61 inches wide by 6.14 inches long, and the thickness is .0043 inches". I presume since its all in inches that this should be 2 (5/8)" wide by 6 (1/8) long and .0043 inches thick (I couldn't easily find a good fraction that approximates this one).
If the cubic yard of cash was assumed to be 3 feet tall, with no meaningful space between the bills, then the stack of bills would be (stack height) / (bill height). Therefore, (36 inches) / (.0043 inches). This would make a stack:
8,372 bills tall
If the bills were lined up end-to-end to form a chain of bills 36 inches long, the number of bills needed would be ( cube length ) / ( bill length ). Therefore, ( 36 inches ) / ( 6.125 inches ). This would be a line of bills:
5.8 bills long
Finally, the bills need to be extended front-to-rear in the cube. To make this extend 36 inches, the bills would need to be ( cube depth ) / ( bill width ). Therefore, ( 36 inches ) / ( 2.6125 inches ). Therefore to make this reach would require:
13.8 bills depth
Not many people carry fractional parts of bills. Indeed, it can be a crime to deface money. Therefore, we will have to take some liberty with the math so that only integer numbers of bills are considered. We can do both high and low approximations to get a range of the number of bills in a cubic yard of cash:
If we take the average number, a cubic yard of cash would be at least $623,714 (if made of US $1 bills). It of course could be as high as $62,371,400 if it was made entirely of US $100 bills.
This would certainly be more than what a 1978 car should ever need for repairs. I'm not aware of any car sold at auction for more than $62 million. Its rare for auction prices to even reach beyond $1-2 million.