8-speed skyactiv automatic. Problem solved.
Mazda \ Toyota building a US plant
- Thread starter 7eregrine
- Start date
8-speed skyactiv automatic. Problem solved.
While I hope they won't do that in any future cars, they have put CVTs in their cars before. If I'm not mistaken, the Mazda Demio (Mazda2) in Japan had a CVT.
Imagine a rotary CVT LOL!!
Speaking of high rpm engines, what type of transmission are used in motorcycles?
If Mazda puts out a Rotary car with a CVT, their stocks would crash so hard LOL
I'm not sure exactly what kind of transmission motorcycles use, but they are not CVTs. They work similar to regular car transmissions with the clutch. The automatic ones that I've tried, are like sequential automatic transmissions.
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- CX5
I think the engine efficiency of the HCCI has nothing to do with the efficiency of the CVT transmission.
I’m talking about the overall system efficiency which includes the entire powertrain. Mazda was on record saying they could forgo developing a new transmission because of the efficiency gains of HCCI. Their opinion not mine. My speculation portion is either it alone hits the target but a CVT could take it further or maybe if HCCI is say as efficient (or nearly) at 4K rpm as 2k rpm it’s just not really needed. The comments in the Car and Driver article about HCCI where they said Mazda engineers claimed the motor wasn’t as sensitive to being in lower fears for efficiency as before led me to infer the later might also be the case. Previous to reading that I thought it was the former.
Direct quote from the C&D article.
“Because the X is more likely to enter CI during lighter-load use and can stay in that ultraefficient mode even at higher rpm, we’re told selecting lower gear ratios has little effect on fuel economy. During our drive in the manual-transmission prototype, we could leave the shift lever in fourth or fifth gear instead of sixth and stay in CI while taking advantage of the engine’s sharper responses to dice through city traffic.”
http://www.caranddriver.com/reviews...on-ignition-gas-engine-prototype-drive-review
Direct quote from the C&D article.
“Because the X is more likely to enter CI during lighter-load use and can stay in that ultraefficient mode even at higher rpm, we’re told selecting lower gear ratios has little effect on fuel economy. During our drive in the manual-transmission prototype, we could leave the shift lever in fourth or fifth gear instead of sixth and stay in CI while taking advantage of the engine’s sharper responses to dice through city traffic.”
http://www.caranddriver.com/reviews...on-ignition-gas-engine-prototype-drive-review
Hmm interesting. The new engine isn't as affected in MPGs when selecting lower gears. So basically you can be in 4th gear and see comparable mpgs as 6th gear but take advantage of 4th gear's responsiveness. If true and Mazda doesn't have to build another tranny from the ground up then they should focus more on its quality and reliability.
Motorcycles have two-shaft, constant mesh sequential manual transmissions. There is a pair of gear wheels for each gear, one on the input shaft and one on the output shaft. Some of these gear wheels are fixed to the shaft and some are free to rotate. Also, some of the gear wheels are free to slide on splines on the shaft, so they rotate with the shaft but are free to move side to side in order to engage with adjacent gear wheels. The transmission is shifted by a ratcheting shift lever, which rotates a barrel-shaped cam that moves a set of forks. The forks engage & disengage gears by sliding the gear wheels next to each other and away from each other. The sliding gear wheels have dogs and the fixed gear wheels have slots, when they are pushed together by a fork the dogs enter the slots which locks their rotation together, so power can be transmitted from/to the free gear wheel through the adjacent fixed gear wheel. Kind of hard to explain in words. Here is a video:
https://www.youtube.com/watch?v=IFjSVgNFd6E
Unlike a manual automobile transmission you can't skip gears and there are no synchros.
Exactly!
