Nova vozila v prodaji, konceptna vozila in vsa vozila, o katerih lahko (zaenkrat) le sanjamo...
 
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-tomi-
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Pridružen: Po apr 05, 2004 9:46 pm

Napisal/-a -tomi- Ne sep 10, 2006 10:12 pm

...mimgrede ...kater nov RWD avto je najcenejši? mx5 za 4.5mio?
 
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Voith
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Napisal/-a Voith Ne sep 10, 2006 10:18 pm

maniac je napisal/-a:pardon 52/48% nekje od l. 1991 dalje

hudičevo blizu, ane ;)

lp


hmm ni mi cist jasn kako je to mozn. ma svinc tok tezk k je masina pod rezervnim kolesom? al je zadn konc iz 5mm plosc zvarjen? kaj kompenzira tezo masine?
 
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Voith
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Napisal/-a Voith Ne sep 10, 2006 10:46 pm

no evo strokovna razlaga. za tiste ki razumete anglesk.

Advantages of front wheel drive

- Interior space: Since the powertrain is a single unit contained in the engine compartment of the vehicle, there is no need to devote interior space for a driveshaft tunnel or rear differential, increasing the volume available for passengers and cargo.

- Cost: Fewer components overall

- Weight: Fewer components mean lower weight

- Improved fuel efficiency due to less weight

- Improved drivetrain efficiency: the direct connection between engine and transaxle reduce the mass and mechanical inertia of the drivetrain compared to a rear-wheel drive vehicle with a similar engine and transmission, allowing greater fuel economy.

- Assembly efficiency: the powertrain can be often be assembled and installed as a unit, which allows more efficient production.

- Slippery-surface traction: placing the mass of the drivetrain over the driven wheels improves traction on wet, snowy, or icy surfaces, although heavy cargo can be beneficial for traction on rear-wheel drive pickup trucks.

- Predictable handling characteristics: front-wheel drive cars, with a front weight bias, tend to understeer at the limit, which is commonly believed to be easier for average drivers to correct than terminal oversteer, and less prone to result in fishtailing or a spin.

- Better crosswind stability.

- Tactile feedback via the steering wheel informing driver if a wheel is slipping.

- Front wheel drive allows the use of left-foot braking as a driving technique.

- Front wheel drive wears down the front tires first so you don't have to switch tires to get the best tires in the rear.



Disadvantages of front wheel drive

- The center of gravity of the vehicle is typically farther forward than a comparable rear-wheel drive layout. In front wheel drive cars, the front axle typically supports around 2/3rd of the weight of the car (quite far off the "ideal" 50/50 weight distribution). This is a contributing factor in the tendency of front wheel drive cars to understeer.

- Torque steer can be a problem on front wheel drive cars with higher torque engines ( > 210 N·m ) and transverse layout. This is the name given to the tendency for some front wheel drive cars to pull to the left or right under hard acceleration. It is a result of the offset between the point about which the wheel steers (which falls at a point which is aligned with the points at which the wheel is connected to the steering mechanisms) and the centroid of its contact patch. The tractive force acts through the centroid of the contact patch, and the offset of the steering point means that a turning moment about the axis of steering is generated. In an ideal situation, the left and right wheels would generate equal and opposite moments, cancelling each other out, however in reality this is less likely to happen. Torque steer is often incorrectly attributed to differing rates of twist along the lengths of unequal front drive shafts. However, Center-point steering geometry can be incorporated in the design to avoid torque steer. This is how the powerful Citroen SM front-wheel drive car avoided the problem.

- Lack of weight shifting will limit the acceleration of a front wheel drive vehicle. In a rear wheel drive car the weight shifts back during acceleration giving more traction to the driving wheels. This is the main reason why nearly all racing cars are rear wheel drive. However, since front wheel cars have the weight of the engine over the driving wheels the problem only applies in extreme conditions.

- In some towing situations front wheel drive cars can be at a traction disadvantage since there will be less weight on the driving wheels. Because of this, the weight that the vehicle is rated to safely tow is likely to be less than that of a rear wheel drive or four wheel drive vehicle of the same size and power.

- Due to geometry and packaging constraints, the CV joints (constant-velocity joints) attached to the wheel hub have a tendency to wear out much earlier than the universal joints typically used in their rear wheel drive counterparts. The significantly shorter drive axles on a front wheel drive car causes the joint to flex through a much wider degree of motion, compounded by additional stress and angles of steering, while the CV joints of a rear wheel drive car regularly see angles and wear of less than half that of front wheel drive vehicles.

- The driveshafts may limit the amount by which the front wheels can turn, thus it may increase the turning circle of a front wheel drive car compared to a rear wheel drive one with the same wheelbase.

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Advantages of rear wheel drive

- Better handling in dry conditions - accelerating force is applied to the rear wheels, on which the down force increases, due to load transfer in acceleration, making the rear tires better able to take simultaneous acceleration and curving than the front tires.
- Less costly and easier maintenance - Rear wheel drive is mechanically simpler and typically does not involve packing as many parts into as small a space as does front wheel drive, thus requiring less disassembly or specialized tools in order to replace parts.

- No torque steer.

- Even weight distribution - The division of weight between the front and rear wheels has a significant impact on a car's handling, and it is much easier to get a 50/50 weight distribution in a rear wheel drive car than in a front wheel drive car, as more of the engine can lie between the front and rear wheels (in the case of a mid engine layout, the entire engine), and the transmission is moved much farther back.

- Steering radius - As no complicated drive shaft joints are required at the front wheels, it is possible to turn them further than would be possible using front wheel drive, resulting in a smaller steering radius.

- Towing - Rear wheel drive puts the wheels which are pulling the load closer to the point where a trailer articulates, helping steering, especially for large loads.
Weight transfer during acceleration. (During heavy acceleration, the front end rises, and more weight is placed on the rear, or driving wheels).

- Drifting is much easier in a rear-wheel drive automobile, as power can be applied to keep the drift going--more power aids the drift. Front wheel drive and four wheel drive cars may also drift, but only with much more difficulty. When front wheel drive cars drift, the driver usually pulls on the emergency brake in order for the back wheels to stop and thus skid.
[edit]


Disadvantages of rear wheel drive

- More difficult to master - While the handling characteristics of rear-wheel drive may be useful or fun in the hands of some drivers, for others, having the rear wheels move about is unintuitive and dangerous. Rear wheel drive rewards skill, and punishes the lack of it. Other layouts are much more forgiving, but don't offer the same rewards in handling.

- Decreased interior space - In a passenger car, rear wheel drive means: Less front leg room (the transmission tunnel takes up a lot of space between the driver and front passenger), less leg room for center rear passengers (due to the tunnel needed for the drive shaft), and sometimes less trunk space (since there is also more hardware that must be placed underneath the trunk). There are some exceptions to this as some luxury vehicles have plenty of room and do not suffer a decreaced interior and rear engine designs do not take away interior space. (See Porsche 911, Volkswagen Beatle, De Lorean DMC-12, Chevrolet Corvair, Tucker Automobile and Alpine (car) for rear engine examples.)

- Increased weight - The components of your typical rear wheel drive vehicle's power train may be less complex, but there are more of them. The driveshaft adds weight.

- The transmission is probably heavier. There is extra sheet metal to form the transmission tunnel. There is a rear axle or rear half-shafts. A rear wheel drive car will weigh slightly more than a comparable front wheel drive car (but less than four wheel drive).

- Higher purchase price - Probably due to more complicated assembly (the powertrain is not one compact unit) and added cost of materials, rear wheel drive is typically slightly more expensive to purchase than a comparable front wheel drive vehicle. This might also be explained by production volumes, however.

- Oversteer and the related problem of fishtailing.

- Depending on the automobile model, traction can be less than that of front-wheel drive; however, heavy cargo can be beneficial for traction.
 
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D_WoMaN
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Napisal/-a D_WoMaN Po sep 11, 2006 5:19 am

se nekateri pozimi v hrib, če ne spelajo z fwd pogonom, pa avto obrnejo in rikverc pelejo v breg. tak je moja mama včasih naredla, če jo je sfukal sred brega še s starejšim avtom. z mazdo 3 pa se smeje drugim k nemorejo spelat, ona se pa pele brez da bi zakopal (skor).
zej ne pravim ker pogon je bolši. js bi mela rwd zato ker me zanima bol športna vožnja (drift), drugače pa še nevem ker avto bom mela k jih je tolk na izbiro, da te glava peče.
seveda ima vsak pogon svoje prednosti, se pa lahka z vsakim tud peleš. vsak naj se vozi z tistim kar mu paše. pomoje je pa manj nesreč z rwd pogonom, zato ker je manj teh avtov k na fwd pogon.
Slika
Vozite po svoji strani ceste, ker po sredini vozim jaz!!!
nismo najboljši, smo pa najdražji :P
 
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nebivedu
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Napisal/-a nebivedu Po sep 11, 2006 7:09 am

Ne gre za napad nate, ampak za pogled s strani, ki ni ne za RWD in ne za FWD!

andrej777 je napisal/-a:Zakaj nosi avte z RWD ?????

KER SO MOČNEJŠI IN NE 75 KM ŠPAROVČKI !!!!!


To je res, vendar če bi bili z RWD samo 75KM šparovčki ta avto nebi nikamor šel in v vsakem hribu bi rabi vlečnco zanjga, sploh pozimi(mislim na bencinarje - dizli majo dost navora če majo 75KM).

andrej777 je napisal/-a:Vse voznike FWD prosin naj probajo prvič ko bo zasnežena cesta v ovinku pohodit gas in glejte kaj se bo zgodilo. Vam jaz povem in verjemte mi da mam prou. Avto bo šel popolnoma naravnost in tudi če volan zavijete do konca. Ko gas spustite se avto ujame (dokler seveda ne pretiravate). IN NE PRVI POGON TE NE VLEČE V SMERI OVINKA AMPAK NARAVNOST VEN !!!!!


Seveda gledaš iz svoje perspektive - gledaš s strani voznika RWD. Vsi vemo da se z FWD v ledenih in zasneženih ovinkih ne dodaja gasa - torej zakaj bi to počel???
Probaj ti poleti na razbeljenem asfaltu v istem ovinku z RWD s slabimi prednjimi gumami dodat gas.

andrej777 je napisal/-a:Kaj se zgodi pri RWD. Odnese zadnji del in z malo znanja in obraćanja volana v nasprotno smer se pelješ z seveda veliko užitka :twisted: :twisted: . Če si nedeljiski voznik gas odvzameš in avto se ujame. In med vsemi manevri inajo prva kolesa dober stik z podlago in lahko z volano celo zaviješ tja kamor hočeš.


Vse pišeš, če imaš malo znanja - kaj pa če si povprečeni voznik(na tem forumu vsaj 75%), ki ob tem da avto malo odnese že tiščijo nogo na bremzi do podna??? Takrat tut zadnji pogon leti iz ovinka koker je dolg in širok.

andrej777 je napisal/-a:Pa še ena cvetka od predhodnih kometarjev. "FWD je bol zihr" :noro :noro KOliko se kvarijo pogonski zglobi in polosovine pri FWD in koliko pri RWD. Ma dejte nehat no. :!: :!:


Tole niti ni cvetka! Koliko recimo saabom ali volvotom crkujejo pogonski zglobi in polosovine???
Spet gledaš iz strani RWD, ne priznaš si pa da so FWD avtomobili ki jih sedajle primerjaš vsaj za polovico cenejši! Primerjaj avtomobile iste kvalitete in tudi iste cene. Ne moreš BMW 7 primerjat naprimer z peugeotom 405, tut 5-ke ne - razlike je preveč. Lahko pa primerjaš BMW 7 in SAAB 95. Pa pomoje vidiš na servisu mnogo več bmw-jev zaradi podvozja kot saabov.


andrej777 je napisal/-a:Jaz sem prevozil že dosti kilometrov tako z FWD, AWD in RWD in zaenkrat me je najbolj prepričal RWD čeprav sem iz hribov in imamo kar hude zime. AWD ima bolši oprijem v hrib in se res ne ustavi kar tako samo v ovinku se pri večini še vedno pojavlja isti problem kot sem ga omenil na začetku in je tipičen za FWD. So svetle izjeme in eden med njimi je sigurno X-drive. Za novega Qatrota nevem samo prejšnji še zmeraj ni bil to kar bi lahko in bi moral biti.


Očitno si malo subarujev AWD prevozil, Ti namreč nimajo skor nič problemov v ovinkih že zadnjih 21 let. Jst nisem imel na leonetu letnika 85 nobenih problemov z ovinki in smo po zasneženi in ledeni cesti trije subaruji (2 komada legacy 2.2 in en leone 1.8) skor leteli na Veliko planino - res pa da smo imeli vsi dobre gume.

Ampak za neukega voznika je in bo še vedno najlažje voziti FWD.
Old subarus never die, they just get faster!
 
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maniac
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Napisal/-a maniac Po sep 11, 2006 7:26 am

Voith je napisal/-a:
maniac je napisal/-a:pardon 52/48% nekje od l. 1991 dalje

hudičevo blizu, ane ;)

lp


hmm ni mi cist jasn kako je to mozn. ma svinc tok tezk k je masina pod rezervnim kolesom? al je zadn konc iz 5mm plosc zvarjen? kaj kompenzira tezo masine?


nisem ravno inžinir, ampak motor je pomaknjen bolj nazaj (npr. pri audiju je kritično ravno to, da je motor postavljen pred prednjo os, zato imajo izrazito težnjo po podkrmarjenju), potniška kabina in potniki so na sredini težišča, bočne ojačitve, zadaj pa je diff..., ki pa tudi ni ravno peresno lahek, pa rezervna guma...bo kr držalo, se zelo pozna na uravnoteženosti vožnje ;)

lp
 
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Voith
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Napisal/-a Voith Po sep 11, 2006 9:13 am

se vseen je spredi za parsto kil razlike. moj avto ma 50:50 z voznikom(z mano :D), samo je komplet menjalnik zadej, pa se masina je komplet alu in ma sam 170kg. tko da mi ni cist jasn kako bi lahk do te teze prsl z masino spredi in sam diferencialom in gumo zadi..



kar se pa teme tice, ve se kaj je superiorno ;)

sam tut f16 je fenomenaln avion, ampak v nepravih rokah postane pac se nekej za razbit in s piste zapelat :D

kdor rad uziva v voznji skoz ovinke si omisli rwd.
awd in fwd nista niti prblizn tko uzivaska kot rwd. amen
 
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nebivedu
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Napisal/-a nebivedu Po sep 11, 2006 9:45 am

Voith je napisal/-a:se vseen je spredi za parsto kil razlike. moj avto ma 50:50 z voznikom(z mano :D), samo je komplet menjalnik zadej, pa se masina je komplet alu in ma sam 170kg. tko da mi ni cist jasn kako bi lahk do te teze prsl z masino spredi in sam diferencialom in gumo zadi..



kar se pa teme tice, ve se kaj je superiorno ;)

sam tut f16 je fenomenaln avion, ampak v nepravih rokah postane pac se nekej za razbit in s piste zapelat :D

kdor rad uziva v voznji skoz ovinke si omisli rwd.
awd in fwd nista niti prblizn tko uzivaska kot rwd. amen


Hmm, zakaj pa potem tisti, ki res uživajo skozi ovinke(rally vozniki) nimajo prov dost vozil RWD?
Old subarus never die, they just get faster!
 
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maniac
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Napisal/-a maniac Po sep 11, 2006 9:57 am

ker je način vožnje pri rallyu naklonjen AWD, predvsem zaradi različnih powšin (pesek, blato, tarmac le občasno, sneg...) in temu prilagojen je tudi način vožnje.

zakaj pa večina F1 voznikov...vozi RWD športne avtomobile?

kr neki :?

mimogrede tudi jst bi ml najraje awd, če bi lahko prestavljal moč naprej in nazaj 100%-0...baje ma nova imreza nekako takšen sistem-pa že navadno bi mel

lp :P
 
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Jorgi
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Napisal/-a Jorgi Po sep 11, 2006 10:02 am

Jst pravm, naj vsak vozi tisto, kar mu najbolje odgovarja...S ceste pa itak lohk z vsakim avtom odletiš, če ne uporabljaš pameti...
Obey me. You'll be happier.
 
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Joie de vivre!
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Napisal/-a Joie de vivre! Po sep 11, 2006 10:11 am

Skratka, da se povrnemo k izhodiščnem vprašanju, kakšne deleže pogonov vidite recimo čez 20 let?
 
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Nixxon
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Napisal/-a Nixxon Po sep 11, 2006 10:19 am

Približno isto bo, ker je še vedno ceneje in to večino ljudi gleda. Manj je tistih ki so zaradi določenih lastnosti ali užitka pripravljeni plačati več.

maniac je napisal/-a:mimogrede tudi jst bi ml najraje awd, če bi lahko prestavljal moč naprej in nazaj 100%-0...baje ma nova imreza nekako takšen sistem-pa že navadno bi mel


Tudi X-drive je tak, poleg tega perko DSCja prenese celotno moč lahko potem še levo-desno oziroma samo na eno kolo. In to baje v parih tisočinkah.
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Jorgi
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Napisal/-a Jorgi Po sep 11, 2006 10:27 am

Težko je kaj takega napovedat, kajti vse je odvisno od velikega števila faktorjev:
- cene naftnih derivatov
-uporaba hibridov
-drugi novi alternativni viri
-cene plina
-razširitev RWD-ja, 4WD na manj "luksuzne" modele > nižje cene > bolj zanimivo za nakup
-podnebne spremembe
-subaru razvije 4wd diesel različico :P
...

Če ne bo kakih revolucionarnih sprememb po mojem mnenju razmerje ostalo približno enako. Za večino je avto prevozno sredstvo za pot v službo, štacuno, po otroke, kak izlet in nazaj domov. Prioriteta pri tem je, da je karseda poskrbljeno za varnost, predvsem otrok, kakkšen je občutek čez ovinke pa zadnja briga...dokler ne gre za odnašanje zadka... Tu vidim prednost 4wd-ja v toliko (ob bolj konkurenčnih cenah kot sedaj), v kolikor bi forsirali kampanjo v smeri > za varnost vaših generacij...4wd.
Obey me. You'll be happier.
 
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andrej777
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Napisal/-a andrej777 Po sep 11, 2006 4:06 pm

Ja Subaruja ravno nisem omenil ampak sem povedal da so svetle izjeme in subaru je tudi sigurno med njimi. Samo če je avto 4x4 to pri vožnji po ovinkstih cestah še ni nujno dobra stvar.
It's not the speed that kills, it's the sudden stop that hirts !!
 
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Voith
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Napisal/-a Voith To sep 12, 2006 1:12 am

Joie de vivre! je napisal/-a:Skratka, da se povrnemo k izhodiščnem vprašanju, kakšne deleže pogonov vidite recimo čez 20 let?


RWD. ostalo bodo nadomestili raketni pogoni :D

dobre stvari nikol ne umrejo. napredne stvari pa povozjo se bol napredne stvari :P
 
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D_WoMaN
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Napisal/-a D_WoMaN To sep 12, 2006 5:12 am

:rofl :rofl :bow :EE :har :rofl maš prav
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nismo najboljši, smo pa najdražji :P
 
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simply
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Napisal/-a simply To sep 12, 2006 9:01 am

Eno vprašanje :

Zakaj imajo " športniki " ala Civic Type R, Golf GTI in R32, Astra OPC, Focus ST, Mazda 3MPS in podobni pogon na prednji par koles oziroma štirikolesni in ne pogon zadaj, če je le ta najboljši? Cena?
 
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Voith
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Napisal/-a Voith To sep 12, 2006 9:36 am

zato ker to niso sportni avtomobili ampak navadni avtomobili ki so nekoliko napiljeni.
Avtomobili ki so bili ze v osnovi zamisljeni kot sportni imajo rwd ali pa 4wd s tem da se vecina moci prenasa na zadnja kolesa.
 
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nebivedu
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Napisal/-a nebivedu To sep 12, 2006 9:38 am

simply je napisal/-a:Eno vprašanje :

Zakaj imajo " športniki " ala Civic Type R, Golf GTI in R32, Astra OPC, Focus ST, Mazda 3MPS in podobni pogon na prednji par koles oziroma štirikolesni in ne pogon zadaj, če je le ta najboljši? Cena?


Zato ker jih drgač ne znajo dobr narest! :twisted:
Old subarus never die, they just get faster!
 
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maniac
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Napisal/-a maniac To sep 12, 2006 9:42 am

ker ma njihova civilna različica prednji pogon in bi bili preveliki stroški razvoja, proizvodnje še RWD različice!
pa še enega fakorja ne smemo pozabiti: kdo kupuje golfa, civica, focusa...?
ljudje, ki nimajo za mercedes, bmw, jaguar, porsche,...torej kupujejo ljudske voze.
ti pa morajo biti čim bolj primerni splošni mentaliteti in največjemu krogu kupcev...torej golf farerjev (ki pa so od nekdaj FWD)...pa že prej omenjene prednosti FWD-ja

lp ;)

rwd je pomemben za ljudi, ki uživajo v vožnji (udobni ali športni), ljudem, ki jim je avto samo za prevoz od točke A do B, je itak vozna dinamika...zadnja stvar pod soncem, važno je da je pocen, pa prostrono-torej FWD
Vrni se na Vozila prihodnosti

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