Do diesels really save money?

Some do but most don't according to a recent U.S. cost-of-ownership study

Published: December 16, 2014, 10:15 PM
Updated: October 11, 2021, 10:03 AM

Do diesels really save money?

Only 11 of 35 diesel-powered vehicles analyzed were found to have a lower total cost-of-ownership than their closest gasoline-engine counterparts, according to a study by Vincentric, a U.S.-based company that specializes in analyzing cost-of-ownership data for vehicles.

The average cost of ownership for diesels was $2,754 more than for their gasoline-powered equivalents when all costs to own and operate were considered – up by $1,737 from the previous study. (All cost figures in $US.)

In addition, the range between the most positive and negative diesel ownership costs was dramatic. The 2014 Mercedes-Benz GL350 BlueTEC saved buyers $7,789 while the 2014 Chevrolet Express Diesel G3500 Wagon cost buyers $13,327 more to own.

The study concludes that a strong financial case can be made for the purchase of some diesel vehicles but consumers seeking shelter from high gas prices won’t always find the relief they expect by turning to diesels.

In this analysis, there were 11 diesels that could be financially justified based on the total cost of ownership numbers. Of those, 10 were luxury models, including four from Mercedes-Benz and three each from BMW and Audi.

Of the 12 luxury diesel vehicles included in the study, 83% were cost-effective. But the only non-luxury model that made a positive economic case was Chrysler’s Ram ProMaster Diesel commercial van.

In most cases, except for pickups, the cost of fuel for a diesel was less than for a comparable gasoline vehicle – by $855 on average. But the average price premium to buy a diesel vehicle was $5,390 – far more than the savings on fuel.

Vincentric determined the total cost-of-ownership using eight different cost factors: depreciation, fees & taxes, financing, fuel, insurance, maintenance, opportunity cost, and repairs. The analysis assumed vehicle ownership of five years and 24,000 km of driving annually.

When all the costs to own and operate all 35 diesel vehicles were taken into account, the average cost-of-ownership was $2,754 more for a diesel vehicle compared to its gasoline counterpart – up by $1,737 from the previous study.

In addition, the fuel prices used in the study were based on a weighted average over the previous five months, so they don't necessarily reflect current prices, which have been dropping more dramatically for gasoline than for diesel fuel. So the actual current cost differential may be even more favourable for gasoline-fuelled vehicles.

The 11 diesels that did achieve lower ownership costs, in descending order of estimated savings were:

o          2014 Mercedes-Benz GL350 BlueTEC  (-$7,789)

o          2014 Mercedes-Benz E250 BlueTEC  (-$3,860)

o          2014 BMW X5 Diesel  (-$2,358)

o          2014 BMW 328d  (-$2,324)

o          2014 Mercedes-Benz GLK250 BlueTEC  (-$1,979)

o          2014 Mercedes-Benz ML350 BlueTEC  (-$1,613)

o          2014 BMW 535d  (-$1,420)

o          2014 Audi Q5 Diesel  (-$1,189)

o          2014 Audi A7 Diesel  (-$748)

o          2014 Audi A6 Diesel  (-$600)

o          2014 Ram ProMaster Diesel 1500  (-$518)