Mazda SkyActiv-X, a spark-aided Homogenous Charge Compression Ignition

Source: Kickaffe via Wikimedia Commons CC BY-SA 4.0

The battle for high efficiency, low emission engine continues to gather momentum when Mazda made a revolutionary announcement earlier this month in the form of the SkyActiv-X engine technology, which Mazda predicts will find its way into production cars by 2019. What the heck is that? Another one of Mazda's trick techno wizardry? In no uncertain term, it is one heck of a piece of tech. It is Mazda's speak for Homogenous Charge Compression Ignition (HCCI) engine, which mixes air and fuel in the cylinder like a gasoline engine, but ignite by piston compression like a diesel engine.

That sounds like a win-win proposition-diesel efficiency combines with clean gasoline emission. Except with a but. A BIG but. There has never been a production HCCI engine in mainstream cars. Why? Well, it's due to this conundrum: timing. Unlike on conventional gasoline and diesel engine where ignition timing can be easily controlled and adjusted with the spark plug (gasoline) and fuel injector (diesel), HCCI has no such luxury. It relies solely on cylinder temperature which if not controlled properly, can create a whole host of nasty problems such as the dreaded knock when it's too hot or compromised combustion if it's too cold.

To remedy this problem, Mazda throws in the spark plug. The idea is that when condition is less than ideal for compression ignition (cold engine, low ambient temperature, high load/rpm), the spark plug will take care of ignition. During highway driving or low load/rpm, the engine will revert to compression ignition to increase efficiency. Speaking of efficiency, Mazda claims their SkyActiv-X tech can improve efficiency by 20-30%. Bold claims there Mazda.

Efficiency aside, this warrants some questions:

1. How will Mazda ensure seamless transition from spark ignition to compression ignition and vice versa? 
2. What approaches will Mazda adopt to control the time combustion occurs?

Let Jason Fenske of Engineering Explained offers some educated guess:

Video Credit: Engineering Explained

    

Mazda says no RX-9; rotary engine to be used as range extender

Source: J. Lyon via Wikimedia Commons CC BY-SA 3.0

Wait a minute?? No RX-9? No rotary engine goodness?? This has to be a heartbreaking moment for rotary's diehard. Though I've never driven a Mazda-powered 'dorito' engine, I can see the appeal of its crisp, smooth, high-revving nature. 

With RX-9 out of the picture, don't expect rotary engine to solely power you down the highway. The good news is you don't have to give up on your dorito yet...but with a twist.  

Masamichi Kogai, Mazda CEO, told Automotive News in an interview that rotary engine will still be around, but as a range extender for their hybrid cars. To be blamed: emission and fuel efficiency.

"Considering regulations such as the zero-emissions vehicle mandate, electrification is a technology we need to introduce in the near future. The range extender would be the first." Kogai told Automotive News.

When asked by Automotive News if there's any plan for a future RX-8 successor with range extender, Kogai suggested that the MX-5 (Miata in the US) already offers an "exhilarating experience". I guess this means if you want the thrill of Mazda's sports car, the MX-5 should be in your shopping list.

So, with RX-9 not in the bucket list and you still crave for the rotary's screaming high rev to get you down the road, get a used RX-8, or if you still own one, cherish it till the end! 

Toyota and Mazda strike up connected cars and electric vehicle (EV) deal

Source: http://www.maltatoday.com.mt/business/technology/

Seems like Toyota and Mazda are getting greener. After inking a deal last year to share each other's efficiency-enhancing technologies (Toyota provides Mazda with their fuel-cell and hybrid tech; in return Mazda provides Toyota with their efficient, compression-optimised SkyActiv petrol and diesel), the Japanese duo has struck up a deal that will see them focusing in developing connected cars and electric vehicle (EV) technologies, according to Automotive News.

The details of the deal, however, still remains under wrap, as Akira Marumoto, Mazda's executive vice president, declined to share the details.

Source: http://www.autonews.com/article/20161102/OEM01/161109974/mazda-says-toyota-tie-up-could-yield-electric-connected-cars

Mazda G Vectoring Control

                               

                                             Source: Norbert Aepli via Wikimedia Commons CC BY 4.0

Jinba Ittai. Literally horses and riders. In Mazda's parlance, that is Mazda's philosophy in delivering their adoring customers with an unadulterated synergy between the driver and the car. Mazda has decided to take the Jinba Ittai to the next level: by adding SKYACTIV-VEHICLE DYNAMICS to the firm's suite of SKYACTIV technologies. The first technology to appear under the SKYACTIV-VEHICLE DYNAMICS family is the G Vectoring Control (GVC), which had been recently added to the facelifted Mazda 3 and Mazda 6.

GVC is basically a software that actively communicates with the engine in response to steering input to optimise vertical loading on each tyres. It does this by either reducing or reinstating torque based on steering angle. 

The idea is that by reducing torque, deceleration is induced. This initiates forward load transfer which helps in improving turn-in response when the driver begins turning the steering. This should, in theory, neutralise understeer (the car wants to go straight even after the steering has been turned).

Once the driver maintains steering mid-corner, the system reinstate torque, inducing acceleration. This transfers load to the rear which stabilises the car. Theoretically, this will make the car less prone to oversteer (the front end turns more, giving the sensation you are spinning out).  

According to Mazda, neither drivers nor passengers will notice GVC at work. Mazda assures that GVC offers significant comfort to the vehicle occupants, as GVC reduces the amount of buffeting experienced by vehicle occupants. This could be due to drivers not having to make corrections directly with the pedals and steering which (I am sure you have experienced this as a passenger) will almost always spill your coffee!

Also, with GVC, Mazda assures that it will enhance straight line stability. In other words, it reduces steering correction on straight road. Most of us barely notice it, but we do constantly make slight steering adjustment to compensate for road undulation and surface imperfection. Thanks to GVC, the lack of steering correction, according to Mazda, should reduce fatigue.

As it is just a software, Mazda assures this will not add weight and complexity as this does not require the addition of extra hardware.

All in all, the newest addition to the SKYACTIV-VEHICLE DYNAMICS family may transform your Mazda into a tiny handling monster capable of making the supercars look silly around curves, or when you are barreling down the freeway. Hopefully, Mazda's tireless pursuit for enhanced Jinba Ittai will show itself in their products.      

Source: http://insidemazda.mazdausa.com/wp-content/uploads/2016/07/mazda_g_vectoring_press-information.pdf