Why are autos 4 and manuals 5?

[DSC]

Just wondering why auto's have less speeds than manuals?  Also, does this contribute to their higher top speed?  If so, how?

manuals have five gears cuz ............... THATS A #### GOOD QUESTION! i have no clue but would like to know the answer

[whateverjames]

i've always thought it was because there are a lot more parts in an automatic, so they had to fit less gears in there. good question though.

5 speed autos are finally coming around. there's a cadillac prototype with a 6 speed auto.

[DSC]

Damnit, caddies can already kick our ass <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'> why do they need manuals!

RX-8 will have an auto 6 speed and the bimmer 7 series will to.... its gonna become common soon

[MingMing]

i thinq the new s2000 has a tiptronic 6spd auto
dun quote me on the &quot;6&quot; but i kno itz gonn get an auto

hhmm mite be because autos can ride the gears lnoger cuz of its better balance

cuz in sticks the first gear lasts u for crap, and in my auto at least, my car rides it up to like 30...
so yea, maybe cuz the tq keeps the car from stalling at lower rpms so the first gear ratio is lower (or closer to where the second gear's ratio woudl be)

the first gear is a higher gear so it makes the car accelerate faster in the 5- speeds and i think mingming makes sense with what he said...... cuz the idle should be lower to make sure the car don't stall out.

[matic 240sx]

an intellegent women once said &quot;well, all i know is.. i put it in 'd' and go...&quot;

[S13Grl]

One of the reasons may be the fact that most autos are slower in acceleration than a five-speed is. With only four gears, the car will use up more gas and deliver almost an equivalent amount of power. Notice how Autos and Manuals have different gas mileage...

[MingMing]

actually s13girl, that's not the reason
the torque convertor in automatics is a thick fluid that gets thrown out by the spinning crankshaft/flywheel, and that fluid causes the input shaft in the transmission to spin, the fact that it's a fluid, and the friction of all those tiny particles within the fluid cause some kinetic energy loss in the form of heat, but keeps the car from stalling, because the engine only needs to swing liquid around, while it's the liquid's job to move the rest of ur car
that's why auto's have slightly worse mileages, but it's also why they dont stall (well at least at the fault of the flywheel to tranny area)

[S13Grl]

(I was just talking out of my ass, forgive me <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>) So, why do autos only have four gears? I thought it had to do with acceleration...

[MingMing]

haha that i got no clue
like i said before, i think the first gear can be ridden longer because u cant stall from too much resistance on the crank/flywheel

cuz the liquid only flows one way, so if there wasnt enough power, the liquid would just be hitting the receiving end of the torque converter and splashing back down, and as ur engine revs up, more liquid comes out, and ur car will start to move, so if the first gear can be ridden longer... so can probably every other gear..
so maybe the gear ratios are just slighty longer for each gear ... now i'm talkin outta my ass! haha but sorta makes sense riite? ;-)

[alchemist]

autos have fewer gears for the most important reason that auto manufactureers listen to....money. &nbsp;It takes more moeny to make more gears. &nbsp;A manual will always be cheaper to produce than an automatic, &nbsp;that said they have fewer gears because of the cost differential. &nbsp;As people want better acceleration and milage, manufacturers are forced to do add more gear ratios, because thats what people with slush boxes want. &nbsp;it just gets cheaper over time with technology to add the gears....look at the turbo 350 and 400 transmissions and the c4 by ford.....they had 3 gears and were great, untill people wanted better gas mileage and what did they add.......overdive and now you get a 4 speed, &nbsp;now they want better acceleration and they make a 5 speed automatic......Untill you get to F1 level transmissions, the manual will always be quicker than the automatic if driven right, its just that people want the power and efficiency of a stick in an automatic so they just add more gears to it

[transient]

Automatics work differently than a manual transmission as well. It's not just two gears powering every different ratio, there are a bunch of gears that work together in different ways to form 4 different ratio's. http://www.howstuffworks.com has a whole section on automatic transmissions, and it should help clear up the question <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

[DSC]

That place is awsome. &nbsp;Clears everything up nicely <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

[MingMing]

haha o yea, forgot that site
hhmm oh and it seems the mileage loss from automatics cant be just from the torque convertor cuz after certain rpms theres a shaft that takes all the power straight from the crank to the input shaft, hehe oops ^_^

[transient]

<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

forget about all the auto/manual crap...get a stick if your car is slow, it will make up for it's slowliness...and if you have like a Viper's kind of horsepower then yeah go ahead and get an auto...hahah....just my point of view here...auto's i will buy: corvette, supra TT, 300ZX TT, Viper, and V8 and up...yup yup...and i don't even know if they make auto vipers or 3zTT auto??...

[transient]

I'll never buy an auto, i hate driving them. Boring for one thing, and not only that, I don't like the fact that I don't have control over the transmission. Sure you've got a gear selector, but that's not totally manual.... I don't like it.

[KoukiS14]

I agree... I love having control over my car.. &nbsp;Unless the car has a shitload of horsepower, auto isn't for me...

-Rob

[Tuck&Poke]

well theres a lot of extra programing to do plus a four speed is smoother because there is less shifting. &nbsp;its a quick fix if you dont want to put money into programing the computer to find the smoothest shift point. &nbsp;also you have to make it compact because yes autos have more parts the the sun gears and planetary gears around it. &nbsp;now yes the five speeds of today are smooth but thats caues they spent the extra money to figure out the perfect smooth shift point. &nbsp;the bmw 6spd auto has super wide gear ratios to reduce shifting and it rivals the best CVT's. &nbsp;so there you go

[Tuck&Poke]

theyre putting 5spd autos in cars cuz of preformance. &nbsp;theres siginificant diffirence between the accleleration time of a 4 and 5spd car. &nbsp;better effieciency is also another reason. &nbsp;theres a lot of factors. &nbsp;not to metion back then manuals used to be 4 speeds and sometimes even 3 speeds. &nbsp;