285's vs 265's
 

I have 285's on my truck now and everytime i go up a hill it shifts out of overdrive. If I go back down to 265's will it make a big difference in that or not much ?

now it did with mine. i have a 5.2 and then i found out i had a bad govenor pressure solenoid and sensor.

define "shifts out of overdrive".. if you mean the tranny kicks down to third gear, that's one thing- if you mean the O/D OFF light comes on AS it shifts down to third- that's quite a different thing, and indicative of something NOT right in your tranny..

If you mean it just kicks down, I could see the extra drag of the wider tire causing you issue.. There are a lot of folks a lot smarter than me that will chime in soon..

Not that I've seen. I currently have 265s, and before the SCT, CAI, Fastman, and exhaust, it was kicking down for hills for me to. Now only the steeper ones make it kick down.

I didn't do individual test runs to see which upgrade had the most effect on the power up hills, but if I had to guess, I'd say the CAI and the SCT. The rest certainly helped though.

Better gears (gear ratio) would also help.

I mean it down shifts when I go up a hill like when it's in cruise control in will down **** and it's like you stopping the gas

The taller tires change your effective gear ratio by .20 give or take, that's noticeable and the added unworthy weight makes a difference, when you add the two, unless you have monster torque, you're gonna feel it.

So me going back to 265's will help with the power, my mpg, and save my tranny ?

It will help in all those areas, yes.

it will also save your front steering componets. thats something im dealing with right now