Mazda Diesel Hybrid
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Mazda reported to be working on diesel hybrids

Mazda may be working to bring a diesel electric hybrid vehicle to markets where diesel is priced lower than gasoline.

Mazda is developing a diesel-electric hybrid vehicle for select markets. The vehicle is not an electric vehicle with a range extender (EREV), but rather a true diesel vehicle with an electric hybrid drivetrain. This is a rare combination, and to some, seems like the holy grail of green driving, but is it?

Diesel Hybrids Could Make Sense In Some Markets, Not the US
The Japan News reports that the plan is for Mazda to market the vehicle where light oil is less expensive than gasoline. The report says that the objective would be to produce a vehicle that could achieve a fuel efficiency of 40 kilometers per liter of diesel. Currently, Japan’s leading seller, the Aqua (similar to the Prius C in the US) achieves 37 kilometers per liter of gasoline, which is roughly a 50 MPG combined rating on the EPA test cycle.

This 8% improvement in fuel consumption would be a big deal in markets that price diesel lower. In the US it would not be as significant since diesel generally costs 10% to 15% more than regular unleaded fuel. In addition, the vehicle would output more CO2 than the Aqua (Prius C) unless Mazda was the first company to produce an affordable diesel that could match gasoline’s lower CO2 emission per mile.

Mazda6 Diesel
Many markets have artificially priced diesel much lower than gasoline in a misguided effort to increase overall fuel economy. Over the past decades, those markets suffered increased air pollution as a result. Mazda had high hopes of bringing its Mazda6 diesel to the US, but has had repeated delays. The company has not given a firm reason why the diesel was not marketed here, but we speculate that the diesel did not exceed the outstanding fuel economy of its gasoline Mazda6 in the US EPA test cycle analysis, while also providing similar performance.

Torque News has asked Mazda for more information and will bring it to our readers if any is made available.

Related Stories:
Why are there no diesel hybrid cars?
Why a compressed natural gas plug-in electric hybrid makes sense
Why can't the 2015 Mazda 6 diesel work in the US?

Photo of Mazda 2 is not meant to convey the new vehicle design.

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The article says that the new Mazda could get 40 kilometers per liter, which, by my conversion equals 94 mpg(US). And, the article states that the Aqua gets 37 kilometers per liter which is similar to the Prius C that gets 50 mpg(US). Someone tell me what I am getting wrong here. I convert 37 kilometers per liter as 87 mpg(US), and I convert 50 mpg(US) as only 21 kilometers per liter. So, by my calculation, if the increase is from 21 to 40 kilometers per liter, then, this is a huge 90% improvement - instead of the small 8% improvement given in the article. And if correct, would completely change the main premise of the article that the improvement percentage is too small to justify interest in the US.
Hello D. Stack. I'm sorry that was confusing. In Japan, and in Europe, the testing protocols are not the same. The source I used (and link to for credit) says the plan is to take the Mazda to "40" with the current Aqua at "37." That is the improvement planned. I mention that the US Prius C, which is the same car as the Aqua, tests out at 50 GPM in the US cycle.
If the Japanese and US test cycles are different than that would explain it. At face value the 37 km/l converts to like 84 mpg. 50 MPG on the combined US test cycle is what that car would deliver if it went thru the US tests. The 8% number comes from the 37 km/l and 40 km/l ratings which would come from the Japanese test cycle. see clear as mud. :)
"Mazda reported to be working on diesel hybrids" Is that why they haven't been able to build a diesel for the US?
Great question. Mazda has a successful Mazd6 diesel in other markets. The company races it too. However, something went awry when Mazda tried to prepare it for US sale. I explore the topic in the third link under "Related Stories." Maybe Mazda found out the same thing that every other automaker has. That affordable family cars with diesel engines are not more fuel economical than gasoline cars.