About a month a go I got new tires. I went from stock 235/70/17s to 265/70/17s. This increased the tire height by just under 2 inches. Since then I've had a couple of issues.

The first thing I noticed is that my truck seems to be dragging ***. It used to have a quickness to it when I needed it to, but not so much now. Is this the tires, or an unrelated issue. I think I've heard other people mention re-gearing when they got new tires, but I didn't think id have a problem with such a small increase in size. Or maybe its just in my head.

Second thing is my speedometer is off. I'm actually going about 3 mph faster than what it shows. I got this from those Sheriff's radar things on the side ofthe road that show your speed and from my GPS. How would I adjust it to my new tire size so it shows my correct speed?

Thanks guys.

 

I wouldn't regear if that is all the bigger tire size you are going to run. It sounds likes you are in the market for a tuner. It can adjust for the tire size and add a little power. Are there any codes and has proper maintenance been done to rule out other possibilities for a loss? Here are a few widely used tuners:
SCT X3 from any SCT dealer and here are a couple places for custom tunes:

http://www.vmptuning.com

http://www.troyerperformance.com

OR

PHP Gryphon
http://www.powerhungryperformance.com/