Averages can be misleading
Comparing the costs of idling and its alternatives can be tricky. Variances in these factors could mean that an investment in an in-cab heater pays off in much less – or much more – time than average:
FUEL PRICE. Analysts have been saying it’s going to stay high, maybe go higher, but no one really knows.
NEED FOR HEAT. If you run in the North, spend more nights in your cab or are cold-natured, you’re a good candidate for not idling.
ENGINE EFFICIENCY. Depending upon the age and efficiency of your engine, your idle speed and parasitic draw (energy required to power in-cab appliances), idling might consume more or less than a gallon per hour.
It won’t be long before you wake up to see frost on the windshield and put on a coat to walk to the diner for breakfast. Add to the turning of the seasons fuel at record highs and more
activist lawmakers restricting idling, and it looks like a good time to see how long it would take an in-cab heater to pay for itself.
You can use this worksheet to figure that out. Where you’re unsure, use the average numbers or adjust them. With further adjustments, the same math would work to assess the payoff for other idling-alternative equipment, such as a gen-set.
COST TO HEAT ONE SEASON BY IDLING
- Estimate the hours per year you spend idling to keep your cab warm.
- Multiply those hours by your hourly fuel consumption while idling to get total gallons used.
- Then multiply by your average fuel cost per gallon to get total fuel costs.
- Using the same hours as in No. 1, multiply by 14 cents – the average cost of engine wear and oil consumption per hour of idling – to get your total non-fuel cost.
- Add the two subtotals for your total costs to heat by idling.
COST FOR USING AN IN-CAB HEATER THE FIRST SEASON
- Using the same hours as in No. 1, multiply by 0.045 gallon per hour, the average fuel consumption for leading in-cab heaters, to find one year’s total fuel consumption for using a heater.
- Multiply by your average fuel cost per gallon to get total fuel costs.
- Add the cost of the heater and installation to get your total cost for heating the cab the first year.
Using the average figures, the cost of buying, installing and running the heater through the first winter will be about $200 less than the cost of idling to heat the cab. With the equipment paid off, savings will be close to $1,400 the following winter, assuming the same hours and fuel price.
