Over Drive

[charliem]

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[fasteddieb]

If anything, in the hills one should be in a lower gear, not a higher one.

Uphill, it avoids lugging the engine.

Downhill, it saves the brakes.

At the very least, I would lock out overdrive in the hills. Possibly do so whenever towing, depending on the trailer/TV combo.

My Flex has "Grade Assist" which holds lower gears longer. On really long grades, up or down, it has paddle shifters that allow it to emulate a manual transmission. With the "Grade Assist" I only revert to that mode once in a great while, but it's still handy.

[pinstriper]

Our 4Runner has a manual shift mode that I use on hills to drop out of overdrive and downshift as necessary to maintain 55-60. Takes me up to about 3,000-3,200 rpm. It is also very helpful downhill to hold the speed down without burning up the breaks.

The other reason you want your RPM's up is the water pump moves more water through the radiator, helping cool the motor. Ditto transmission cooler and even engine oil. Important in the heat.

[dp]

Thank you, makes sense. My overdrive is always on so I will just hit the button and I will be good. For some reason I thought racing the engine more with OD off was bad. Thank you,
    Ron

[david]

One thing to be aware of and I think it only applies to older TVs, is that some TVs don't lock out the torque converter in lower gears. An unlocked torque converter means that you are converting some of the torque of the engine into heat which is very bad for transmissions if left in that mode for long.

I know my fifteen year old Ford F150 would only lock the torque converter in the upper two gears.

One way to tell is while pulling a load up a hill at a steady speed, goose the throttle a little bit, but not enough to shift into a lower gear. If the rpm slowly climbs, ok the torque converter is locked. But if it jumps a few hundred rpm immediately, that probably means that the torque converter was working, ie unlocked.

David

[dp]

Thanks Dave.

[walt3]

Ronnie one question what tow vehicle and what trailer do you have?

[sandyu]

I pull my 10.0 with a Honda Odyssey. The majority of the trip it stays in fifth gear "over drive". I turn about 2100 rpm most of the trip. However, to avoid a lot of gear changing I switch to my tow mode in city driving. I'm no expert but lots of gear changing is a bad thing. I think that's thing you need to watch. Cruise control is really bad about causing lots of gear changes.

[dp]

Thanks KY, I will remember that. I can not afford a new trans.
   Ron