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Why Is Diesel Getting More Expensive Compared to Regular Unleaded

Most of the claims by diesel advocates are dubious, but one fact that is hard to argue against is that diesel costs more than regular fuel in every U.S. state.

Most automakers have abandoned diesel cars and crossovers for the U.S. market. The reasons are many, including price, and emissions hassles now that VW has been proven to have faked emissions and fuel economy results for generations. However, one other reason why automakers are cautious about introducing new cars and crossovers with diesel engines is the growing gap between diesel and regular unleaded fuel.

Presently, the first business day of 2018, diesel is more expensive than gasoline in every U.S. state. That fact is based on the average prices of both fuels as determined by AAA*. A more important trend is that the price gap between the two fuels is growing.

Last year at this time, the percent difference between diesel and regular unleaded was just 6.4%. That difference still made it a bad deal for cars and crossovers, since modern gasoline engines can match or beat the power and fuel efficiency of modern diesel-equipped cars and crossovers. Today, the gap between these two fuels has more than doubled, with diesel costing 13.4% more than regular unleaded. A year ago, diesel was thirty-six cents per gallon less expensive than it is today. Gas has gone up too, but only by fourteen cents. On average, in the U.S. diesel costs thirty-eight cents per gallon more than gasoline.

Trucks and rigs built for towing will continue to use diesel, but automakers are going to have a very hard time convincing car and crossover buyers that diesel makes any sense at all given its emissions, performance, and price shortcomings.

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*Note that the prices used in this story are reflected in the image at the top of page. The AAA source referenced changes over time.


JP (not verified)    September 14, 2018 - 6:58PM

I was hoping this article would actually try to answer the question. Instead, it just shows data for the increasing gap between diesel and regular unlead that anyone can find with a quick google, or just by looking at the prices on at the pump when they drive by a gas station. This article is pretty much a waste of bandwidth

Ben (not verified)    December 31, 2018 - 7:19PM

My diesel gets better fuel mileage than my sisters prius. Not sure where your “facts” come from, but I have owned both gas and diesel vehicles. When you compare the same makes and models in a gas to diesel flavor in the real world, diesel is more efficient per gallon every time. But thank you for attempting to increase the gas vehicle to diesel vehicle ratio. That makes my fuel cheaper.

John Goreham    January 4, 2019 - 9:08AM

In reply to by Ben (not verified)

With your frugal driving style imagine the amazing mileage you would get if you were the driver of her Prius. We take our MPG facts from the EPA and also from our own testing in some cases. The fuel costs above are taken from AAA's daily fuel cost website.