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hahahaha...dua pendapat yg berbeza.... mana satu yang betul neh...
tgk keter la brand apa kot...
jagung Post at 29-8-2009 12:08 PM 
Supaya Tak Confius ni article dari internet:
Overdrive can refer to two different things. An overdrive is a device which was commonly used in automobiles to allow the choice of an extra-high overall gear ratio for high speed cruising, thus saving fuel, at the cost of less torque. Usually the final or top gearis called overdrive. Non direct drive gears increase torquemultiplication at the expense of higher engine rpm and thus, decreasedfuel economy. It also refers to a combination of gearing inside a transmission or transaxlewhich results in the output speed being greater than the input speed.In the latter case, "overdrive" does not refer to a physically separateidentifiable part/assembly.
Early manual automotive transmissionswere limited to three or sometimes four speeds, with only the mostsophisticated being five speeds. This left an unfulfilled need for ahigher gear ratio for highway cruising, which was filled by theaddition of separate overdrive units (auxiliary or bolt-on). Todayhowever, automotive transmissions manufactured since the 1980s tend toinclude overdrive within the transmission. In the aftermarket earlynon-overdrive vehicles and 3/4 ton or heavier diesel trucks (where fueleconomy and more gears are always in demand)are the main use of bolt-onauxiliary overdrives.
Generally speaking, overdrive (OD) is the highest gear in thetransmission. Overdrive allows the engine to operate at a lower rpm fora given road speed. This allows the vehicle to achieve better fuelefficiency, and often quieter operation on the highway. When it isswitched on, an automatic transmission can shift into overdrive modeafter a certain speed is reached (usually 70+ km/h [43+ mph]depending on the load). When it is off, the automatic transmissionshifting is limited to the lower gears. For an automatic transmission,it is almost always best to select overdrive and allow the transmissionto control engagement of the overdrive. (It may be necessary to switchit off if the vehicle is being operated in a mountainous area or whentowing a trailer). With a manual transmission, overdrive should usuallybe selected when the average speed is above 70 km/h (approx. 43 MPH).
The automatic transmission automatically shifts from OD to direct drivewhen more load is present. When less load is present, it shifts back toOD. Under certain conditions, for example driving uphill, or towing atrailer, the transmission may "hunt" between OD and the third gear,shifting back and forth. In this case, switching it off can help thetransmission to 'decide'. It may also be advantageous to switch it offif engine brakingis desired, for example when driving downhill. The vehicle's owner'smanual will often contain information and suitable procedures regardingsuch situations, for each given vehicle. Virtually all vehicles (cars and trucks) have overdrive todaywhether manual transmission or automatic. In the automotive aftermarketyou can also retrofit overdrive to existing early transmissions.Overdrive was widely used in european automobiles with manualtransmission in the 60's and 70's to improve mileage and sport drivingas a bolt-on option but became increasingly more common for latertransmissions to have this gear built in. If a vehicle is equipped witha bolt-on overdrive (ie: GKN or Gear Vendors) as opposed to a havingoverdrive built in you will typically have the option to use theoverdrive in more gears than just the top gear. In this case gearchanging is still possible in all gears, even with overdrivedisconnected. Overdrive simply adds effective ranges to the gears, thusoverdrive third and fourth become in effect "third-and-a-half" and afifth gear. In practice this give the driver more ratios which arecloser together providing greater flexibility particularly inperformance cars.
What been explained by Fast earlier is true.
Jangan pening ya.
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x prasan lak aku kalo off od, gear jadi drop 1...
yg aku prasan rpm jd tinggi je...
pasni kena tengok balik ni...
kalo layan lap pun aku suka off od...
xyah tekan brek slalu sgt...
xla kena kutuk dgn membe2..silau la cucuk ko kat lap..skit2 tekan brek... |
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Jangan biasa sangat main OD2 nie....Kalau silap2 nasib tak baik gearbox cepat kaput...
Awal tahun nie keta ibu saya jenis Ford baru tukar seketul tranmission auto (rebuild/recon) dari keta jenama Nissan mcm rojak pulak:kant: Buat kat specialist gearbox kat Batu Caves kos dalam RM 4500 ...Aku rasa ok laaa tuee...Kalau seketul baru kena RM 12K pulak... |
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x prasan lak aku kalo off od, gear jadi drop 1...
yg aku prasan rpm jd tinggi je...
pasni kena tengok balik ni...
kalo layan lap pun aku suka off od...
xyah tekan brek slalu sgt...
xla kena kut ...
elisdend Post at 30-8-2009 06:17 PM
Hati hati di jalan raya. kalau kena brek, brek jangan bergantung sangat pada OD |
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bole tak bagi den poso dgn aman? apo sobut2 namo den nih..
orangdalam Post at 29-8-2009 12:39 
wooiiii... idop laie ekau neh...? |
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kete aku plak sebalik nya...hahaha...camner tu...
t@t Post at 29-8-2009 12:20
hurm..
tetebe jer aku rase confuse da..
kalo kat dashboard aku der tulis "O/D OFF" dye blinking2..so maknenyer on ker atau off..:cry: |
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Post Last Edit by PerKasa at 13-12-2010 10:57
teruja pulak nak jwb
ok bagi korang senang paham
bila O/D tu on, gear kereta akan auto ke 1 2 3 dan empat
bila O/D tu off gear kete akan HANYA ke 1 dua dan 3 je
so bila ka hway ko mesti nak lajukan so kenalah guna sampai kegear 4 kan
jadi kena lah on kan O/ D tu supaya gear tu sampai ke gear 4
kalau off kan o/d ianya sampai ke gear 3 je
so kat hway tak lajulah sbb sampai gear tiga je
bila ko drive kat hway guna gear tiga minyak akan mencanak bunyi kete kasar
dan enjin akan rosak
boleh mengerti tak? |
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If you press the button on the gearshift, the OD will turn off and the light on the dash should light showing that OD is off. Press the button again, and the light should go off showing the OD is on.
Under normal driving conditions, the OD should be on and the light on the dash should be off.
So remember, when OD light is off, the OD is on. |
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teruja pulak nak jwb
ok bagi korang senang paham
bila O/D tu on, gear kereta akan auto ke 1 ...
PerKasa Post at 13-12-2010 10:52 
hmm...aku rasa lain keta lain pulak definisi OD ni kot.
Aku pakai Grand Livina A/T. Bila tekan button (button kedalam) dia akan nyala lampu OD kat panel meter..dan time tu rpm jadi tinggi seolah drop ke 4th gear. Bila tekan sekali lagi (button timbul), gear jadi mcm asal balik 5th gear. Salu pakai bila nak take over dan cornering utk traction. |
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bila O/D tu on, gear kereta akan auto ke 1 2 3 dan empat
bila O/D tu off gear kete akan HANYA ke 1 dua dan 3 je
so bila ka hway ko mesti nak lajukan so kenalah guna sampai kegear 4 kan
jadi kena lah on kan O/ D tu supaya gear tu sampai ke gear 4
kalau off kan o/d ianya sampai ke gear 3 je
so kat hway tak lajulah sbb sampai gear tiga je
bila ko drive kat hway guna gear tiga minyak akan mencanak bunyi kete kasar
dan enjin akan rosak
PerKasa Post at 13-12-2010 10:52 
explanation ko salah, OD tu bukan gear limitation, tapi over reaving limiter. maner ader such thing auto 123 jer kalau off... kat highway sekali pung, biar pong OD ko off, kompom leh sampai final gear. cuma engine reaving akan tinggi pada setiap gear shift compare kalau OD on, baru 3.5, dah shif next gear.. |
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Enterprem gak walopon dah diterangkan. Dgn percubaan bahasa pasar.
OD = low engine rev atau kurang enjin mengaum.
Cth katakan anda di hiway dgn kelajuan 100kmj;
Bila OD 'ON' = enjin rev 2,500 rpm (kurang deruman)
Bila OD 'OFF' = enjin rev 3,200 (lebih deruman enjin).
Jadi bila memandu, kita nak enjin deruman paling rendah supaya minyak economical. Maka, default setting is OD =' ON'.
Bila nak pakai enjin mengaum lebih? (Sila rujuk kurikulum lesen memandu):
-town driving utk engine drag braking
-turun genting utk engine drag braking
-jalan raya biasa dimana anda sentiasa perlu memotong.jengkaut, lori sawit.
Dan OD = 'ON' direkemen hanya bila crusing di hiway.
Dan rasanya, takdenya enjin malatop atau gearbox rosak kalu OD sentiasa 'ON' atau sentiasa 'OFF'. |
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O/D off mase nak memotong.. kasi pickup..
biasenye kereta aku kalau OD on dalam 110km/j 2500rpm
mase nak pickup sikit masa memotong O/D off kelajuan makin naik jadi 120~ dengan
rpm naik sampai 3500 lebeh kurang.
masa turun bukit OD off pon OK. |
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mcm tunggang terbalik jer explanation korang....:re:
aku rasa mcm ada silap jer.... |
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Reply 56# danedzya
habis betul nya mcmana pak? kalau gini boleh?
bila OD off maksud nya kadar bukaan valve bagi kemasukan petrol lebih tinggi. bermakna kadar putaran cam shaft adalah tinggi. kekuatan enjin menjadi lebih dan memberi lebih kuasa pemanduan.
tapi bagi keadaan pemanduan biasa, OD button mesti lah di'release'kan. jika tidak, penggunaan minyak petrol menjadi lebih besar. betul ke ni?  |
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Enterprem gak walopon dah diterangkan. Dgn percubaan bahasa pasar.
OD = low engine rev atau kuran ...
kabukiman Post at 24-12-2010 20:01 
explanation bahasa pasar terbaik setakat nieh.. |
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Post Last Edit by myoujin at 27-12-2010 17:44
kalau stended bawak keter 70km/j keatas tu kat bandar ke highway ke elok le
OD on.
kebanyakan kereta OD akan function bile 70km/j keatas.
OD on = better fuel consumption = less torque |
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tambah kesimpulan.....
OD off = sport mode bagi sesetangah kenderaan & more traction
OD on = Economy mode |
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Post time 29-8-2009 10:22 PM
