When to use overdrive

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Aug 8, 2006 | 08:47 AM

#21

bob200587

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Joined: Feb 2005

Posts: 3,546

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From: Nashville, TN

Quote:

Originally Posted by tom_mag

You will always get better mileage in OD so leave it on.

I'm gonna have to disagree with you there.....

Aug 8, 2006 | 05:49 PM

#22

tom_mag

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Joined: Jul 2006

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Quote:

Originally Posted by bob200587

I'm gonna have to disagree with you there.....

Ok, If your truck is stock it will always get better mileage with the OD on. If you put big tires on it then the effective gear ratio is higher so you have less torque to pull you up a hill so you need to downshift.

Also, the lockup torque converter on the newer models can unlock and feel like a shift, but its still in OD under light throttle. It only locks up in overdrive when you are cruising and then it doesn't have the loss of efficiency that you get with a normal automatic. If you look on www.fueleconomy.gov you will notice that a 2000 4runner automatic gets better mileage than the manual trans model. If you do the same comparison with a 1988 4runner the manual trans model gets better mileage. So you may be right for your 1st gen, but for third gens I say leave it in OD so that your TC can lockup and give you better mileage.

Last edited by tom_mag; Aug 8, 2006 at 05:52 PM.

Aug 9, 2006 | 04:19 AM

#23

Rick F.

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Joined: Nov 2002

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From: Far western Kentucky (transplanted from central PA)

Quote:

Originally Posted by tom_mag

Ok, If your truck is stock it will always get better mileage with the OD on...

I agree with bob200587 that always keeping OD "on" will NOT get you better mileage and I have real life data to back it up. I calculate my mileage at each fill-up and drive the same 65 miles round trip to work every day so I feel confident that my data is not skewed.

I suggest each person determine what works best for them, since everyones' driving habits and terrain differ. Our vehicles don't know how to read our technical "know-how"...

Aug 17, 2006 | 01:01 AM

#24

grimpy

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Joined: Jun 2005

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From: SoCal

Here is a twist... When I drive with OD OFF, towing... I get the same MPG as I do normally driving with OD ON and ECT ON.

Aug 17, 2006 | 06:50 AM

#25

ZUK

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Joined: Oct 2003

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From: Prescott AZ

Quote:

Originally Posted by jct61765

I just had a guy argue with me, almost violently, about when to use overdive. I dont tow anything, I always leave my O/D on. He says you have to shut it off below 40mph or it will toast your tranny. Oh, he has a Dodge Durango. We dont even have to talk about that. Does anyone here shut off their O/D under 40mph?

The Durango guy is on meds. Leave your OD ON except when pulling a heavy load that offer a strain to the drivetrain.
Add a tranny cooler and change your fluids yearly and that tranny will last 300k miles or longer.

Aug 17, 2006 | 07:12 AM

#26

ASU4runner

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Joined: Nov 2003

Posts: 536

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From: Blowing Rock, NC

Quote:

Originally Posted by drguitarum2005

... you should turn OD off when towing and in mountainous areas with hills etc.

I live in the mountains and I couldn't agree more with him.

Jan 20, 2020 | 07:47 PM

#27

Chase Miller

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Joined: Jan 2020

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If you look on www.fueleconomy.gov you will notice that a 2000 4runner automatic gets better mileage than the manual trans model. If you do the same comparison with a 1988 4runner the manual trans model gets better mileage. So you may be right for your 1st gen, but for third gens I say leave it in OD so that your TC can lockup and give you better mileage.[/QUOTE]

I have a 2001 4runner and the TC locks up at 50 MPH, I'm not always going that fast. What about speeds below that? Like say 35-40 MPH? I feel like leaving the overdive on at such slow speeds is unnecessary unless it's at a long distance. P.S the automatic probably gets better mileage than the manual because the gear ratios are larger.