CVT provides a seamless shift through an infinite number of effective
gear ratios between maximum and minimum values.
It's a very swift and hassle free gearbox, but there is a large jump in
gear ratios between second and third.
Like a CVT, an HSD transmission continuously adjusts the effective
gear ratio between the engine and the wheels to maintain the engine speed while the wheels increase their rotational speed during acceleration.
The smaller engine is mated with a continuously variable transmission (CVT) that works by, well, continuously varying
the gear ratio between the engine and the drive wheels, rather than notching between 5 or 6 fixed ratios.
Toyota, Ford, and GM instead use a variation of a power - split design that allows some power to flow mechanically and some electrically when the gas engine is running via a planetary gear arrangement that allows for a continuous range of effective
gearing ratios between the engine and the wheels.
Additionally, the 12 - V DC motor (an EC motor is optionally available) is cooled to such a degree that motor load can be stepped up with the advantages of a lower
gear ratio between motor and actuator shaft and a higher actuating torque.
Not exact matches
The ring
gear is again fixed for a low overall drive
ratio between the motor and the half shafts powering the Volt's front wheels.
Finally, there's a feature called Virtual Intermediate
Gears that creates half speeds
between the transmission's real
gear ratios.
Rather like the chassis tweaks it's difficult to identify the ST200's shorter
gear ratios in terms of straight - line acceleration — you'd need to drive it back - to - back with an ST — and there are actually occasions where the shorter
gearing forces you to shift up
between corners rather than being able to hold the lower
gear.
The direct injection for the V - 6 intensifies its faint clatter, the revs rise, and the eight - speed automatic snaps through the
ratios with a little pause
between gears as the fuel cuts out for a millisecond to speed the process.
The DSG gearbox works extremely well, giving a decent impression of a conventional automatic under gentle use while seamlessly swapping
between its seven
ratios, but offering near - instant changes when driven a bit more keenly — or when over-ridden with wither the push - pull
gear selector or (optional) steering wheel paddles.
The PTU can switch
between the two
gears in about a tenth of a second, and it chooses its
gear ratio solely base on what the rear transmission is doing: in first and second
gears, the PTU is in its low range.
Unlike a conventional transmission with four of five
gears that change the final drive
ratio in steps, a CVT uses a steel belt and a variable pulley to infinitely change the final drive
ratio between a minimum and maximum setting.
The key difference
between a manual and an automatic transmission is that the manual transmission locks and unlocks different sets of
gears to the output shaft to achieve the various
gear ratios, while in an automatic transmission, the same set of
gears produces all of the different
gear ratios.
Honda's Continuously Variable Transmission (CVT) is standard equipment on the Civic Hybrid and provides a 9 percent wider range
between the maximum and minimum
gear ratios to enhance acceleration and minimise engine rpm at high speeds.
That said, it's nowhere near as supple as the RS 7 — even in Comfort mode — and the big gap
between second and third
gear ratios of the otherwise slick eight - speed auto became a chore in tight going.
Ratios have been ideally spaced to help provide a smooth transition in -
between gear changes.
The new automatic 9 - speed gearbox of the Mercedes shifts smoothly and is very flexible thanks to a wide range reduction
ratio between the first and the ninth
gear.
Like most new DCTs, the new transmission features dual dry clutches and two input shafts, allowing for seamless torque delivery
between shifts, as well as
gear - jumping to the optimal
ratio, should the driver ask for it.
These systems may provide added features such as a varying of torque distribution
between axles or varying
gear ratios.
The second fixed
gear (FG2) is located at the
ratio of the synchronous transmission point
between EVT1 and EVT2.
The hybrid system doesn't require a conventional transmission so it is fitted with a single fixed -
gear ratio that creates a direct connection
between moving components.
The new nine - speed has a wider 7.6:1 overall
ratio — the difference
between the first
gear ratio and the top
gear ratio — compared to the eight - speed transmission, with a «deep» 4.69 first
gear that supports excellent off - the - line acceleration and a «tall» 0.62 top
gear for low - rpm highway cruising.
With only small changes in rpm
between gear ratios, the ideal
gear is on hand in virtually any situation out on the road.
With two pure mechanical
gear points, infinitely variable
ratio in
between, start - stop, regenerative braking, pure electrical mode, electric power assist, 100 % towing capability — the hybrid one seems to be better use of quite expensive planetary mechanics.
The overall
gear ratio selected provides a balance
between the amount of tractive torque available from the electric motor and the vehicle speed range available before the EV mode is disengaged at higher vehicle speeds.
A
gear ratio is the relationship
between one
gear and another — such as one
gear up where the bicycle pedals are, and the other
gear back near the rear wheel, connected by the chain.
Compared with a conventional automatic transmission, which shifts among up to five
gear ratios, a CVT uses the entire range of
ratios between low and high
gears.
Unlike conventional automatic transmissions, which shift
between discrete
gear ratios to match the engine speed to road speed, the Murano's Xtronic CVT is stepless, adjusting the relationship through two variable - diameter pulleys and a steel belt.
Transmission duties are taken care of by a 9 - speed automatic gearbox that is claimed to offers greater range of
ratios and shorter steps
between gears.
The greater the disparity in size
between these two pulleys, the greater the range of
gear ratios, efficiency and performance the transmission can offer.
Based on Automotive News Full - size Pickup segmentation A key element in the Ram 1500's exceptional performance, fuel efficiency and shift quality, the available TorqueFlite ® 8 - speed automatic transmission features 40 different adaptive shift patterns and a wide
gear ratio with small, evenly spaced steps
between the
gears.
Where the six - speed bounced back and forth
between gears downhill and was hesitant to downshift when climbing, Ford's 10 - speed just settled into a
gear — with so many to choose from, it could choose a more accurate
ratio — and pulled smoothly and strongly.
Incorporating an additional clutch and
gear over Kia's existing 6AT, the
ratio between the top
gear and the lowest
gear in the new transmission has been increased by 34 % over the 6AT, resulting in greater fuel economy and improved NVH in higher
gears and faster acceleration and climbing performance in low
gears.
Now these are surprisingly good figures for a four - cylinder limo, aided no doubt by the slick - shifting gearbox which remains smooth and rarely hunts
between gears despite so many
ratios.
Both vehicles benefit from nearly imperceptible
gear changes due in part to very evenly spaced
gear steps
between each
gear ratio.
It's helped considerably by a six - speed automatic transmission, which allows both a wider spread of
gear ratios and closer
ratios for less engine - speed change
between shifts.
The six - speed automatic was smooth in operation, and its many
ratios and the engine's broad torque band ensure that the correct
gear for the situation is chosen more often than not, which is good, as there is no manual
gear selection; the driver gets to choose
between D and L only.
The solution is a new 10 - speed unit with close
ratios that bring the
gears closer together, and even spacing
between each
gear.
That's because it's always using the optimal
ratio and the transmission doesn't have to shift
between gears.
Honda's fourth generation of Continuously Variable Transmission (CVT) is standard equipment on the Civic Hybrid and provides a 9 percent wider range
between the maximum and minimum
gear ratios to enhance acceleration and minimize engine rpm at high speeds.
6 - speed automatic transmission The adoption of the 6 - speed AT, increased by two speeds over the base 4 - speed, enabled the overall
gear ratio range to be widened and the gaps
between each
gear to be reduced to achieve a better close
ratio.
Significant differences
between the two generations are the extra 50 mm in the Mk2 Sport's wheelbase, helping refine the chassis, the addition of a sixth
gear ratio for less frenetic cruising, and an uprated 1.6 - litre four - pot that swells power from 123bhp to 134bhp.
Command - Trac evenly disperses power
between all four wheels, while Rock - Trac offers best - in - class performance off - road by providing the Wrangler with a 4:1 low -
gear ratio with an extra-low crawl speed and amped up torque.
The i - MMD system does not use a conventional transmission; instead, a more compact unit has a single fixed -
gear ratio, to create a direct connection
between moving components and a smoother transfer of torque.
The relationship
between the belt and the different diameter pulleys gives you what amounts to a
gear ratio, but so many more
ratios are possible than you can get with plain
gears.
A wide -
ratio, 6 - speed transmission has smaller steps
between gears than a typical 4 - speed automatic and offers improved shift quality and faster acceleration.
Such performance is made possible because the
ratio steps
between its
gears are smaller than those of other transmissions.
The shifts
between gears are almost imperceptible and it has no trouble finding the correct
ratio on the open road.
The 10 - speed automatic has 7.39 overall
ratio for smaller steps
between gears.