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Unread 10-27-2006, 11:24 PM   #1
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Default When should I turn off overdrive?

This is probably a dumb question, but when should I turn off overdrive? I've been told that turning it off will improve gas milage...can I turn it off whenever I'm not pulling a heavy load, and will turning it off help my gas milage?

EDIT: BTW, it's 2WD...it's the truck that's in my sig.
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Unread 10-28-2006, 04:28 PM   #2
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This is probably a dumb question, but when should I turn off overdrive? I've been told that turning it off will improve gas milage...can I turn it off whenever I'm not pulling a heavy load, and will turning it off help my gas milage?

EDIT: BTW, it's 2WD...it's the truck that's in my sig.
Overdrive is what makes your engine move at a slower speed so you do save gas, people use it on the highway to save gas, it should be on.
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Unread 10-28-2006, 06:25 PM   #3
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Leave overdrive on when not pulling a load or traveling highway speed, it will allow the vehicle to shift into high gear (overdrive). Which in turn runs the motor at a lower rpm which saves gas and strain on the motor.

If you have ever been pulling a load and gone up hill, you notice that the vehicle will downshift to keep power up and make it up the hill. Often overdrive is too high a gear for pulling loads uphill. So what the overdrive selct is meant for, is to turn the final gear drive off, so as to prevent the vehicle from switching gears often when pulling loads uphill or at highway speed.

When cruisin or highway driving, leave overdrive on.
Whn city/towning turn it off.
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Unread 10-30-2006, 06:27 AM   #4
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Stop and go traffic turn it off (stop lights stop signs Etc.)
Constant speeds leave it on(highways interstates Etc.)

all really overdrive does is put more torque to the wheels so it's easier to pull things and stay at lower RPMS. But does increase gas mileage.

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Unread 10-30-2006, 08:46 AM   #5
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Another important feature of overdrive that is commonly overlooked is that it uses an automatic car's gears to help slow the car and it does not shift as soon in the RPM range. this means that the car stays in each gear longer. This greatly helps to save the transmission and prolong its life as it does not have to shift as much.

So the rule of thumb is, as Mikey44 said,

city traffic or under 45mph - turn OD off
Highway or over 50mph - turn OD on
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Unread 10-30-2006, 03:47 PM   #6
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But i usally Leave my overdrive on for some odd reason lol not because i want it on becaus ei forget about it, lol my truck gets bad MPG in the first place 12/15mpg the worse gas ever. Makes up for it in performance YAY!!!!

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Unread 10-31-2006, 12:25 AM   #7
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all really overdrive does is put more torque to the wheels so it's easier to pull things and stay at lower RPMS. But does increase gas mileage.
Yes by using a lower gear. Which has a higher ratio thus putting more torque to the rear wheels.
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Unread 10-31-2006, 07:29 PM   #8
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But i usally Leave my overdrive on for some odd reason lol not because i want it on becaus ei forget about it, lol my truck gets bad MPG in the first place 12/15mpg the worse gas ever. Makes up for it in performance YAY!!!!


Yeah, I know what you mean....My pickup gets an average of 11 miles to the gallon. (And I drive mainly interstate.)
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Unread 11-01-2006, 12:36 AM   #9
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Yeah, I know what you mean....My pickup gets an average of 11 miles to the gallon. (And I drive mainly interstate.)
Lol the truck i used to drive at an old job back in pittsburgh, was a Dodge Ram 2500 with the 8.0L V10 and an auto trans. It got 5.7-5.9mpg dialy driving. Then in winter when we would get on highway for traveling to accounts to snow plow, itd get about 6.4mpg. It was a gas hog like no other!
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Unread 11-06-2006, 05:57 PM   #10
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Wait a second, I think you guys have this backwards... Overdrive gives you a higher final drive ratio, which makes the engine run at a lower RPM per wheel RPM. In other words, you're geared "taller" and have less available torque at the wheels. An "underdrive" gives you the feeling of more power because the engine will be running at a higher RPM. The lower RPM saves gas because parasitic drag in an engine is squared as RPM rises.

But it is correct to keep OD engaged when >45mph steady, and off when driving <45mph and stop-and-go driving.

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