Now that Chevrolet has revised their EPA mileage estimate for the Chevrolet Cruze Diesel, from 42 mpg to 46 mpg, we need to revise our own estimates.
Initially, we called for a break-even period of 115 years, based on TrueCar’s formula for calculating the break-even period on fuel economy packages. For argument’s sake, we used TrueCar’s formula of driving 15,000 miles per year, though we used Chicago, IL as our sample for gas and diesel prices. The lowest prices found on GasBuddy at the time of the original article was $3.50 for regular and $3.80 for diesel respectively. For consistency’s sake, we’ll stick with that, though obviously the break-even point will change along with fuel price fluctuations.
Since city and combined figures haven’t been announced yet for the Cruze diesel, I decided to only use the highway figures for a similarly equipped gasoline 2LT . As the calculations show, the Cruze diesel does use a smaller quantity of fuel annually, but that’s offset by the price premium one is required to pay for diesel. Using the initial 42 mpg highway rating yielded a mere $22 in annual fuel savings and a $2,550 price gap. At that rate, it would take over a century -roughly 115 years – for a potential owner to “break even” on the Cruze diesel. But with the 46 mpg rating, the fuel savings grows to $142 annually. This shortens the break-even time to about 18 years; still fairly long, but much shorter than it would take compared to opting for a Cruze Eco. The reason for this is because at 42 mpg, fuel economy increases roughly 10 percent, while fuel costs rise by about nine percent. It’s a wash. But at 42 mpg, fuel economy improves by nearly 20 percent so you have a fuel-cost adjusted increase that goes from one percent to 11 percent, thus cutting the payback time by a factor of almost ten.
And now, to pre-empt some of the questions/criticisms from last time: yes, this analysis is incomplete due to only having the highway figure. I am aware of that, but I wanted to show that TTAC is not afraid to revise their predictions accordingly, in an open and transparent fashion. When the final numbers are released, we can do a proper comparison with the Jetta TDI (and maybe the Mazda6 diesel as well). I’m also aware that people buy diesels for the driving experience (low-end torque etc), but I’ll leave that one to Alex Dykes or whoever ends up reviewing the car.
Data below, for anyone interested