Numbers, mpg related, PT.1:
i was doing some cleaning (surprised how much dust accumulates.....) and uncovered a spreadsheet i did concerning gas mileage and engine conversions and how much money it would take to operate each drivetrain combo:
Now, this was originally done for a pickup, but this could apply to any rear drive gm (particularly chevy) car originally available with a small block v-8. Gas was around $3.25 and diesel was around $3.75 when i did the paper i think last winter, so not too far off.
A truck with a typical stock small block is going to get around 16mpg. If you swap to diesel (the 6.2/6.5 engine) you'll go up to 24. (you might even be able to go 27 or higher, but let's go with 24 for now just to be conservative). Any rear drive car with a small block can be converted to run the 6.2 diesel engine as it bolts in the the stock mounts and has the same bellhousing pattern as a small block. If you're turned off by diesel you can substitute an LS engine in for purposes of this discussion.
In fuel costs, it will cost .20 cents per mile if sticking with gas and gas is $3.25 per gallon.
If you run diesel @ $3.75 per gallon , then the cost per mile is .15 cents.
SO after 1,000 miles, it cost $203 on gas and $156 on diesel. On one hand not too heavy because, i think, it would take, on average a few weeks to go 1000 miles on an average commute. On the other hand, somewhat significant because with weekend trips factored in, 1,000 miles can come quickly.
At 10,000 miles, it costs $2031 on gas and $ 1562 on diesel. Again, not too heavy in my opinion---it takes me about 11mos/ year to achieve 10,000 miles. Again, here it depends on how much overall driving you do; Weekend trips, shuttling the kids to soccer, do you go shopping alot etc.?
At 45,000 miles, it costs $9140 in gas and $7031 in diesel. My point here is it may take quite a while---i think it was 250,000 miles before you break even when you consider the costs in converting to diesel----a new 6.5 engine is $8000 from gm, i've seen remans for $3000 though.
If you have your money parked at 3% (shouldn't be too hard to do) OR if you had put it in municipal bonds, you'd get at least 5%. Putting money in these investments vs. buying a new engine it's likely you may never break even. i missed out on the municipal bonds among other things because i'm not a smart man. (picture Suze Orman scolding you with finger outstretched).
This is why i've decided to stick with gas.