Are Diesels Cheaper to Maintain Than Gas Cars? Study Says ‘It Depends’

Source: Justin Sullivan/Getty Images
Source: Justin Sullivan/Getty Images

The ongoing debate between owners of diesel-powered and gasoline-powered vehicles regarding which is more cost-efficient is about to get a tad more ambiguous. While a great deal of consumers often choose one over the other in an attempt to score a few extra miles out of every tank, or even to help reduce emissions, it doesn’t necessarily translate into direct cost savings.

At least that’s the conclusion of a new study from automotive industry analysis firm Vincentric, which says that though many people subscribe to the idea that diesel or gasoline-powered vehicles save them money over the long haul, it completely depends from model to model. Diesel vehicles typically cost consumers more at the dealership, but they also tend to be cheaper in terms of fuel costs. Based on the analysis done by Vincentric, it’s clear that diesel-powered vehicles come with some advantages, but can also end up being more of an expense than some buyers expect.

“The Vincentric Diesel Analysis showed that of the 35 diesels measured, 11 had total cost of ownership that was lower than their all-gasoline powered counterparts,” the study reads. “The average price premium for a diesel was $5,390, with average fuel cost savings of $855. When all costs to own and operate a diesel were taken into account, the average cost of ownership for diesels was $2,754 more than their all-gasoline powered counterparts.”

It’s also noted that there is a pretty wide rift between the vehicles offering the best and worst savings, with “the 2014 Mercedes-Benz GL350 BlueTEC saving buyers $7,789 while the 2014 Chevrolet Express Diesel G3500 Wagon cost buyers $13,327 more to own.”

2013 Mercedes-Benz GLK250 BlueTEC
Source: Mercedes

Which brands come out on top?

The method that Vincentric used for comparing the two different vehicle types was fairly extensive, and included looking at fuel prices’ weighted average against the past five months, an assumption that 15,000 miles were driven annually, and that the vehicle in question is owned for five years. When taking all of these things into account, there were 11 diesel vehicles out of the 35 that can be financially justified based on the total cost of ownership. These models include four Mercedes-Benz units, three from BMW, three from Audi, and one from Ram.

While 11 out of 35 isn’t all that impressive of a number — it does represent less than half of all models tested, anyway — there are other advantages that diesel offers that make consumers want to purchase them. More specifically, the increased advantages in fuel economy and efficiency have long-been a big attraction for consumers looking to save some money. The study did find a number of models that offered the greatest benefits in fuel economy over their gasoline-powered counterparts, and that list included three models from Audi’s A series, and two Mercedes models.

As for which vehicles offered the lowest overall fuel costs — for those looking to minimize their fuel purchases — Volkswagen appears to be the brand to pick, although Mercedes and Audi again placed some representatives on the list.

Again, the total cost of ownership for a big percentage of these diesel vehicles appears to outweigh any benefits and savings in fuel costs, however. With these findings in mind, one more caveat to include is that the percentage of diesels available on the market that save money actually contracted this year compared to 2013. 31% of diesel vehicles for sale this year save consumers money, whereas in 2013, that number was 46%.

panamera s e-hybrid
Source: Porsche

Hybrids, plug-ins, and gas prices

With the costs of owning a diesel or gasoline-powered vehicle now more clearly defined, it’s fair to wonder how hybrid or electric cars stack up as well. Luckily, Vincentric actually did a similar study to get to the bottom of things, and the results were fairly similar to what was found with diesel vehicles. It was found that hybrid cars oftentimes come with a higher sticker price and other peripheral costs, meaning that the cost of ownership will often outweigh any savings on fuel in the long term.

From that study, it was found that roughly one-third of hybrid vehicles tested — and there were 31 of them — actually save consumers money.

Plug-ins and other all-electric vehicles also tend to be a bit more expensive, but do they follow along the same trend as diesel and hybrid vehicles in terms of cost? Again, it’s hard to say. Though Vincentric hasn’t waded into plug-in territory yet, it’s probably safe to assume that the answers would be mixed. The Nissan Leaf, for example, can be purchased for a very reasonable price and doesn’t require any fossil fuels at all, though buyers will sacrifice long-range commuting for it. That can be contrasted with models from Tesla and other luxury automakers, which come with a very high sticker price.

Though the popularity of diesel, hybrid, and plug-in vehicles is definitely on the upswing, there are market forces at work that may actually stunt those segments’ growth in the short-term. That force, of course, is the epic downfall of oil prices, which has led to gasoline being priced at less than $2 per gallon in many locations across the United States. This may sway some consumers, who had previously been considering more efficient options like hybrids or plug-ins, to stick with a gasoline-powered model.

We could also see a boom in sales of trucks and SUVs, which tend to drink up a lot more fuel in comparison to their smaller, more efficient counterparts. But what’s important to remember is that markets and prices are not static, and that even though gas prices are low now, they won’t be forever. That’s something consumers should take into consideration, although with gas near 1990s-level prices, there’s a temptation to go for the gas-guzzler.

The takeaway from these studies? Just because you think you’re going to be saving money by purchasing a specific vehicle, that may not be the case. Look carefully at the total costs of ownership, not just a vehicle’s sticker price and fuel economy rating. Though the technology is getting better, and cars are becoming cheaper to operate, there’s still plenty of reason to take all costs into consideration when purchasing a new vehicle.

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