Less engine, more gears

[some_other_dave]

Six-speeds in the mass market of this country are similar--they shorten each gear so that the sixth is about the same revs/mile as an earlier five-speed.

-soD

[jamesqf]

Originally Posted by Frank Lee

Right- and you go from 1st through each gear to 24th from a stop.

No, if I'm riding on flat pavement. But it's not at all unusual for me to start out riding on a level stretch, climb a few miles of paved road at 6% grade, then go off on a mountain trail. On a ride like that, I do use the majority of the gears. (Of course there's some overlap between the front 3 gears, and the rear 7-8.)

FTM, my pickup has 10 speeds, when you combine the 5 speed transmission with high & low range in the transfer case. And I do use that low range on roads where 1st gear in high range would stall out.

[MPGranger]

I see CVTs and DCTs being the transmissions of tomorrow. A traditional automatic is being phased out, although you go to the dealership and the sheeple don't know what anything is so they label everything as an automatic transmission. CVT has continual power to the road, but has higher torque loses. (Which is why it is so hard to put them into trucks) The DCT, dual clutch transmission, is essentially twin manual transmissions that are shifted by the computer so that the lack of power during a shift is kept to a bare minimum. As the odd number gear transmission begins to let go, the even number gear transmission begins to grab. Pretty slick, there are 6speeds like this and luxury 8speeds, with 10 and 12 easily foreseeable. A traditional automatic transmission is just a mess of moving parts (read failure points) adding more to this mass, just doesn't seem wise. Although, when my father found out that my girlfriend, now wife, was driving a manual tranny; he knew we would probably get married. I love manual transmissions. And I have owned several 6 speeds; I agree that most are true 6 speeds, and what would be best for FE is an overdrive 6 speed tranny.

[IamIan]

Originally Posted by MPGranger

I see CVTs and DCTs being the transmissions of tomorrow.

The additional gear ratios of the CVTs can be an asset for the ICE ... which is very susceptible to non-ideal RPM and Torque combinations ... but the CVT transmission itself is significantly less efficient than the Manuals transmission.

I agree in the near term I expect more CVTs ... but as Main Drive Electric motors grow in size and Market % ... I wonder if that will continue to hold long term?? ... Electric motors are not as vulnerable to efficiency losses as ICEs are , from fewer ideal gear ratio options... as that starts to play a more dominate roll , we may start to see fewer manual gear ratios ... maybe a DCT style you mention.

[rmay635703]

Originally Posted by Frank Lee

What do you gain with all those gears? If your deal is max acceleration rate, that is what you gain. If your deal is fe, you lose from all that shifting- a most inefficient process what with all that throttle blipping and halting forward motion- and you lose from a transmission that has more moving parts and I would imagine more internal friction.

In the '80s the eco-stick trans options were 4-speed instead of 5.

With my 5-speeds I'm always skip shifting, like 1-3-5. I would like to only have the 1-3-5 gears and throw 2-4 away and save the internal trans losses.

I usually only use 1st or 2nd and 5th, no need for any of the other gears except when
1. Pulling
2. going up hills.

My insight I find myself using more gears, cobalt though is stuck in 5th 99% of the time.

I am guessing frank that if you have a motor that is underpowered enough you could actually "need" the gears or if you overgeared where 5th was unusable a good chunk of the time like my suburban or my subaru 360 that doesn't have enough power to skip any gear without coming to a stop.

[jeff88]

Originally Posted by rmay635703

I am guessing frank that if you have a motor that is underpowered enough you could actually "need" the gear.

I rhink that is what cripple_rooster was getting at in the OP and I think that is indeed the future with regards to better FE. The tranny may be more likely to fail with more parts, but that is offset by smaller and less cylinder-ed engines. And with the reviews (read as Consumer Reports) coming back that small engines with turbos isn't really working, more gears is would be the next logical step.

[P-hack]

On shifting speed, if time spent shifting is of concern:

1. Simply loading the alternator can help slow the engine between gears during upshift.

2. for faster results, It could be a well calculated pre-ignition too.

How much power/energy to slow a 4cyl for upshifts within one engine revolution? Does it justify regen starting and stopping?

Though clutch is nice since it transfers much of the energy from the higher rpm engine rotating mass, that would be the comparison, lower rotating mass=better, or use hydraulic motor/generator for the starter (and stopper) if you are stuck with a flywheel, maybe

[cRiPpLe_rOoStEr]

The folks might remember that, in Europe due to smaller engines which were more usual for a long time, a higher count of gears was usual there, and in Brazil due to fuel costs we tend to follow the European school more often. The case of the Fiat Palio Weekend was a specific one, since it had an engine even smaller than the base offering in the Euro-spec version (a 67hp 1.2L 8-valve gasser), while the Brazilian domestic versions had the 1.5L as the base engine before the introduction of the 1.0L engine.

[litesong]

Originally Posted by rmay635703

I usually only use 1st or 2nd and 5th, no need for any of the other gears except when
1. Pulling
2. going up hills.

Originally Posted by IamIan

The additional gear ratios of the CVTs can be an asset for the ICE ... which is very susceptible to non-ideal RPM and Torque combinations ... but the CVT transmission itself is significantly less efficient than the Manuals transmission.
I agree in the near term I expect more CVTs ...

The two exceptions given are the reason for 5(or 6 or 7+) gears & there are other reasons, too.

I loved my CVT which transferred power to the ground continuously & I did get better mpg than the 5 speed manuals delivered. It made stop & go commuting, bearable & even elegant without shift shock. Yes, travel from 1 to 15 mph can be...... OK, if you can't go 60mph. Also my car, which didn't have an efficient body or engine, had the ability to get 32-33mpg traveling over 4000 & 5000 foot mountain passes & was due to CVT's ability to set the exact right geariing for ALL slopes & configurations.

However, CVT's extreme unwarranteed repair cost caused me to trade my car before such an event occurred. Wanting my accustomed manual transmission again, I could never find it on the dealer's lot & got an extremely fine deal on a 6 speed automatic Elantra. Bolstered by the 100,000 mile warranty, I expect no out-of-pocket transmission repairs for a decade & possibly long after that! Plus, the Elantra, bad-mouthed for poor mpg by lead-footers, is delivering 39mpg average. Under the conditions, I don't think a manual could have rendered higher mpg than the auto.

The auto tranny is a pleasant experience, tho not the wonder of the CVT.

[Xist]

Originally Posted by litesong

However, CVT's extreme unwarranteed repair cost caused me to trade my car before such an event occurred. Wanting my accustomed manual transmission again, I could never find it on the dealer's lot & got an extremely fine deal on a 6 speed automatic Elantra. Bolstered by the 100,000 mile warranty, I expect no out-of-pocket transmission repairs for a decade & possibly long after that! Plus, the Elantra, bad-mouthed for poor mpg by lead-footers, is delivering 39mpg average. Under the conditions, I don't think a manual could have rendered higher mpg than the auto.

The auto tranny is a pleasant experience, tho not the wonder of the CVT.

My sister and I made a trip to California and back in her husband's new Elantra. I had thought that it was a beautiful car and was surprised that they bought it new for $16,000. We got at least 36 MPG the entire trip, "driving the speed limit." It turns out that is Sister for 4 MPH over, so 79 in a 75.