hey guys...juss had a question concerning Overdrive...i have a 99 Dodge Ram...and i always had the doubt...which settin of Overdrive gives you the most ponnies out of your engine..and which one gives you a better gas millage??

 

OD off gives you the most ponies. What it does is it keeps your tranny from shifting into 5th gear therefore more torque and power. When you hit 40-50 mph it shifts into fifth so it takes less rpms to turn your wheels therefore less power and strain on your engine when crusin the interstate.

 

Actually it does not increase or decrease the horsepower it simply keeps the engine in the powerband by not letting it shift into the higher gear. As for gas mileage OD will definitely give you better MPG because it allows the engine to run at a lower rpm at higher speeds.

 

Also, driving with overdrive on in stop and go driving situations, i.e. around town, can be harder on your transmission. When you get on the gas, it has to shift out of overdrive to get back into the powerband to make you accelerate. This is a lot of extra shifting. I leave mine off while around town, towing/hauling loads, and hilly drives, then turn it on only when on the highway above about 50.

 

not necessarlily, it comes down to how much torque you have at any given rpm vs throttle position. IMO. if you are in 3rd doing 65 mph and say your motor is turning 2500 rpm and is at a point where you need very little throttle to maintain that speed you mpg should be better compared to being in OD and your motor turning 1800 rpms with less torque (you need more throttle to maintain 65)... really depends on the motor and how it's built. at what rpm is the motor most efficient.

I say this because when I was experimenting with my exhaust I found that when I lost low end torque, my mpg dropped 1.5 mpg. when I increased my low end by reducing the dual outputs down to 2.25" my mpg jumped back 1.5 mpg and my low end torque was increased if not back to where I started, probably more (no dyno sheet to show how much either way). all of this with the same driving habbits, od on...

If I didnt experience this 1st hand, you wouldnt be reading this post [sm=happybounce.gif]