So I whipped together a small Excel worksheet to estimate the payback period. You need to enter the cost of the mod, the cost of gas, miles driven per year, estimate the mpg before and after the mod. It computes the annual gas savings in both gallons and dollars and the years for the return on your investment. You can down load it from:

http://www2.cemr.wvu.edu/~wwwasph/temp/

Of course the big trick is to estimate how a modification will affect your mileage.
You could also use the calculator for the analysis of a new car purchase. For example use the cost difference between a hybrid and conventional car as the "cost of the mod", then enter the mpg for each. (For any economist in the audiance, I know about discounting for the time value of money, just thought it was more sophisticated than needed for this situation.)

 

I would have thought it would have been more than a year or so, but I guess not.
Not only are you saving moolah on gas, you are also saving the wear and tear of the engine if you cruise on the freeway a lot with a T-5 instead of the toploader. And, since the toploader needs work anyway, why not change to the T-5?

 

Yea, an over drive is almost a must have if you're doing much driving. How many new cars these days do not have OD? I cannot think of any.

 

Highhilleer - this spreadsheet is amazing! Great job. [sm=drooldude.gif]

Glen - may I suggest adding this to the FAQs section for future reference?

 

It is there now as we speak.

 

Soaring, the spreadsheet is on a temporary space that is subject to disappear at anytime. I would be pleased if you could arrange a more permanent home for it. I'm not looking for any pride of authorship issues or anything like that. Just making it available for anyone who would find it useful is enough. Send me a pm if you want to discuss.

Highhilleer.