Originally Posted by TWerner
400/250 is 1.6. So if I read that correctly, your 3 diesels are running 60% more hours total, but burning 6% less gallons of fuel than your 3 gas mowers? That comes to almost exactly 41% less fuel burned.
I assumed the diesel and gas mowers were the same size and mow at the same speed. It's more than a 41% savings if the diesels cut more per hour.
Using $3.50/gallon to be conservative, and 50 gallons/week on gasoline, that's $175/week on gasoline versus $105/week on diesel. Buying ag diesel might make the savings a bit more, say $75, but even so, if you only save $25 a week on a mower running 400 hours a year, it will take a while for a diesel to pay for itself.
For a better analysis, I'd need the hours per week per mower.
Then I can plug in the numbers to show how much you save per hour on fuel. Again, I am assuming your diesels and the gas mowers cut the same area per hour.
The argument for area isn't completely relavent, The big diesel mowers are open terrain mowers, the smaller gas mowers are hill climbing & close quarter trimmers.
I'm working in litres here but the ratio's will be the same. Yes we are using marked diesel in the mowers.
Gas $1.205, 2621 litres 2010
marked diesel $0.9765
Season for mowing is 25 weeks
Excluding the small out front mowers as only auxilliary mowers, They will only burn a couple of gallons a week as back up's and specialty mowers, (steep hill work with 4x4, power sweeping, aerating).
Each 9 goes out with a Z gas. unit 1 72" and 54". unit 2 60" and 60". The 9's of course are slightly faster. I've got the gas at 4.22 L/hr about 1.1 US gallon /hr.
$5.06/hr 54 & 60 inch
Still working up diesel numbers