Underdrive pulley- why don't you have one?

[aldive]

I gather that they are a good idea for the V6 SOHC engine.

I would have to say UDPs are one of the best mods that I have done to my truck.

 

[aldive]

bump

 

[daves97sport]

This or that?

I would have to say UDPs are one of the best mods that I have done to my truck.

Having done all other improvements - intake/exhaust/TPS/e-fan, etc... - would the next best mileage improver be the pulley, or programmer mod?
This is for an OHV/5spd motor. With all other mods above(e-fan latest still to be evaluated), I didn't notice any improvement in mileage, but saw very nice power improvements. Unfortunately, power seems to kick in around around 2800RPM, just before my normal shift point which brings R's back to 2000.

 

[aldive]

bump

 

[1Bad04]

I have them on my 4.6. It could be a placebo affect of sorts, but I felt a gain in power. No dyno tests to prove it though. Haven't really noticed the better fuel mileage though. Will be able to get a more accurate reading after I switch back to the stock wheels/tires for winter, which will probably be within the next couple of weeks.

 

[CDW6212R]

Al, I am not going to do any real performance testing with the changes that I have, and yet to do. I do keep records of all changes, and mpg at each fill up. I haven't had time and weather to do the balancer yet, but the few other changes have added to my mileage.

Over all I am now almost at 15mpg, and before last month I hovered between 12mpg and 14mpg. Hopefully the PCM tuning will bring it together and reach the 10% gain I had hoped for with the V6 at work. My Scangauge still suggests under 10mpg at work.