OK, folks, Mike has graciously loaded my spreadsheet onto the site; you can download it here:http://www.busconversions.com/files/Per-Mile-Operating-Cost.xlsA few notes:
First off, this is something that I threw together just for myself a few years ago. As such, it's nothing fancy, and probably not laid out and organized in the manner best suited for other people to use. Before sending it to Mike, the only changes I made were to change a handful of abbreviations and words to make it more understandable, and formatting a few things to make the whole thing more readable. There are no locked or protected cells, so be careful where you type.
Second, please understand that I did not sit down one day and come up with every possible contributing factor to the operating costs. I took my best shot at it, and I have been adding items as they've come up for us; for example, we just did our first brake job, and I added the costs for that just yesterday.
Lastly, this is strictly variable operating cost. Wear and tear is included in the sense that these items must be replaced periodically. That said, overall depreciation on the value of the bus is not included, nor are insurance, registration, and other similar items that have a fixed annual cost.How to use:
You will need either Microsoft Excel
or Open Office Calc
to open this. It is in Excel's native format, but Calc will open it just fine; Open Office is a free download from http://download.openoffice.org/
and is available for many platforms.
There are two pages; switch between them with the tabs at the bottom labeled "Driving" and "Generator". One calculates the per-mile cost of driving the bus, the other calculates the per-hour cost of running the generator. We only have one diesel tank, so this is set up to use the same per-gallon diesel price on both sheets; if you have a separate diesel tank for your genny, you will need to change the formula in A5 on the Generator sheet.
All the numbers on the top section of both pages are calculated by the spreadsheet. These represent the cost, in dollars per mile (or hour), of each item, such as a lube/oil/filter change. At the bottom of this column of numbers is the total overall cost per mile (or per hour) of driving the bus or running the genny. I have bolded these numbers to make them stand out.
Once you've adjusted all the "factors" on both pages for your bus, you will mostly only ever change cell A20 on the "Driving" page. This is where you enter the current price per gallon of diesel fuel; don't forget the trailing nine tenths of a cent (the sheet displays this value to the nearest whole cent, but uses the entire number for the calculations).
Your bus is different from mine, and probably how you maintain it is different as well, so you will probably need to change many of the numbers on the bottom part of each sheet. For example, I know my generator, which is both enormous and ancient, burns 1.1 gallons per hour when running. Yours probably burns less, and you would enter this number in A19 on the Generator page. We change our main engine oil per DD recommendations every 15,000 miles, and the full service with oil, oil filters, fuel filters, and chassis lube that we do at that interval has been running an average of $400, so these numbers are in A23 and A22 respectively on the driving page. We also use synthetic tranny fluid so our numbers for change interval and cost per gallon are likely different than yours; the spreadsheet also accounts for the size of the transmission sump which may also be different. You get the idea: change whatever factors you need to match your own situation.
I hope some folks find this useful. If anything doesn't make sense, or you find a mistake or major omission, post here and I will see about updating the sheet.