So I finally decided to run some numbers. Very back of the napkin stuff and subject to LOTS of personal prefs.
First, the $10,000 diesel engine cost (Ford). Some argue that the price premium remains throughout the life of the vehicle. Maybe, but inflation probably argues against that a bit. Call it even for now.
Second, I looked at some expenses for the first 100k miles. My experience right now. My 6.0 l diesel got about 10 MPG when camper on. On my recent trip, my 6.2 l gasser got about 8 MPG.(That might improve a bit after break-in and more flat land driving). Current prices in my town are about $3 for regular and $3.33 for diesel. Going with those forward (dumb assumption), the extra gas would set me back $4200 over 100k miles.
On the diesel side, DEF gets about 600 MPG. 166.66 gals in 100k miles currently about $6/gal is $1000.
Oil changes every 7000 miles might suggest about 15 in the 100k of travel. I do my own. The diesel oil filters (motorcraft) are about $10 more than the gas.: $150. The diesel would use about 6 qts more per change, or 90 qts difference. At $5 per qt, that is $450.
Net difference at this point: $2600 extra to have the lower mileage gas engine.
Now I expect to drive my F-350 less than 10k per year (12 years experience with old one). So I'll take at least 10 years to accrue 100k miles.
IF (and this is purely hypothetical) I invest the extra $10,000 and get 5% return, I would have around $16,000 after 10 years. Or, thought of another way, I have $500 per year to spend on extra gas by using the growth and dividends from the $10k. Much more than I would need based on the previous calculations.
So OK. obviously your assumptions can vary greatly from mine. More miles per year, dealer oil changes, future prices, investment return. However, I am satisfied that, for now, the money angle works for me.
Rick
