SKYACTIV®-G - GASOLINE ENGINE

In developing the new SKYACTIV®-G engine, Mazda engineers focused on dramatically improving efficiency without sacrificing performance and responsiveness. In fact, since better efficiency fundamentally means extracting more energy from the same amount of fuel, SKYACTIV®-G is more powerful and more responsive than the engine it replaces.

Dramatically increasing the engine's compression ratio was the biggest key to capturing more of that energy, but high compression comes with challenges. Higher compression ratios can lead to knock, an inefficient and potentially destructive combustion process where the heat and pressure in the combustion chamber causes the air/fuel mixture to ignite too soon. This is especially true when running regular 87-octane fuel. That's why traditional engineering wisdom dictates that it's impossible to run a 13:1 compression on any kind of pump gas - even premium. Mazda's powertrain team rejected this wisdom. Instead, they flexed their engineering muscle to develop a web of interconnected technologies that overcome this issue, while simultaneously squeezing out even more efficiencies on other fronts.
 

SKYACTIV®-DRIVE - AUTOMATIC TRANSMISSION

An efficient and responsive engine is of little use if the transmission is slow to find the right gears or loses hard-earned energy on the way to powering the wheels. Before designing the SKYACTIV®-Drive transmission, Mazda engineers studied every available transmission technology. A Continuously Variable Transmission (CVT) was rejected due to its slippy, disconnected feel - which goes against everything Mazda stands for. And while a Dual Clutch Transmission (DCT) gets props for being efficient and having the same direct, connected power delivery as a manual transmission, the DCT's computer-controlled clutch is difficult to control at low speeds.

Reimagining how an automatic transmission should behave,
Mazda's engineers set out to design SKYACTIV®-Drive with the
best attributes from both a conventional automatic and a DCT.
Four key performance targets were identified:
• The fuel efficiency of a manual transmission
• Quick, direct shifting like a DCT
• Easy to control at low speeds like a conventional automatic
• Smooth, seamless shifting



First, Mazda engineers focused on improving the torque converter.
A conventional torque converter is still the smoothest, easiest
way to control a car at walking speeds (like pulling in and out of
your driveway or creeping through rush-hour traffic), but they're
inefficient at higher speeds. The solution is to only use the torque
converter below 5 mph, where it works the best. The rest of the
time, SKYACTIV®-Drive uses a multi-plate clutch to directly and
efficiently transmit power.

Because of the torque converter's more limited role, Mazda
engineers were able to make it smaller, leaving room to package the
clutch and torque converter in the same space as a conventional
torque converter.

Locking out the torque converter achieved the team's "direct,
connected feel" and fuel efficiency performance goals. But
achieving fast, smooth shifts required a quest for speed and
precision deeper inside the transmission. Thus, a new mechatronic
module was developed, combining the transmission control
computer and all the sensors and shift solenoids into one unit.
Each of these compact modules is individually calibrated when the
transmission is assembled, so the computer can learn the precise
response characteristics of each part it has to control.

As a result of this innovative approach to automatic transmission
design, SKYACTIV®-Drive has the lowest losses of any equivalent
competitive transmission design. It upshifts smoothly and directly
like its DCT competitor, it rev-matches perfect downshifts every
time - even faster than the DCT - and it yields 4% to 7% gains in
fuel economy.*
*4% gains when paired with SKYACTIV®-G and 7% with SKYACTIV®-D.

 

SKYACTIV®-BODY

It is impossible to construct a vehicle that delivers precise
handling characteristics and exceptional ride comfort without first creating a
brilliant structure. In creating the SKYACTIV®-Body, Mazda's team
was determined to build an extremely rigid body (30% more rigid than
current models) while reducing its weight by 8%. Reducing weight improves
handling, efficiency, acceleration and braking; every part of the car is on
a "diet," with the goal of shaving 220 pounds from each new car!

In order to accomplish all this without compromising safety, a three-pronged approach was required: 

Optimize the structure - In previous body structures, the
vehicle's crash energy was mostly carried in the floor. With the
SKYACTIV®-Body, however, crash loads are distributed through
the floor, along the roof and through the side-impact door
bars. The structure was made more efficient (both stronger
and lighter) by eliminating corners in each load path to create
a straight frame from the front to the rear. The back half of the
center tunnel was also reinforced, so load directed to the floor
can be carried there as well. With the crash load now dispersed
more evenly, the body is able to keep occupants safer, while
reducing weight and increasing stiffness

Enhance the manufacturing method - Building a more
efficient structure created manufacturing challenges. Some
reinforced areas couldn't be accessed by conventional spot
welders, so new techniques like laser welding and advanced,
structural adhesives - known as weld bonding - are used
instead. These enhancements allowed Mazda engineers to
create a series of continuous load paths, or rings, ensuring
that load forces are dispersed across the vehicle structure
rather than to just one area

Use more high-tensile steels - In previous Mazda body
structures, approximately 40% of the structure was
comprised of high-strength and ultra-high-strength steel
alloys. In creating the SKYACTIV®-Body, engineers increased
that amount by 50% (from 40% to 60%)
The net result of these efforts is a structure that is 8%
lighter and 30% stiffer than the one it replaces.