Tires and Odometer

So i have 305/70/R17 tires on my 2004 silverado crew cab. How much is this affecting my odometer and speedometer?

probably a lot. in order to have the speedo work properly you have too "plus size the tires".Say your truck came stock with 265/70/16...then you want to change to 17" rims...tires would need to be 275/65/17 to acheice the same overall diameter.. Can affect speedo, abs, and handling....Not sure but some power chips will aloow you to reconfigure the ecm to accept the new size but not sure.

What is the size of your stock tires?

I know the speedometer is off by 6mph but how is this messin up my odometer? Is it goin up quicker than it should or less? Stock tires were 265/70/R17.

Your speedo is 7% to slow which means when your speedometer reads 60 your actually going 64.2 mph. Now as far as the odometer goes the traveled distance will be greater than the measured distance but i'm not sure how much...

I know the speedometer is off by 6mph but how is this messin up my odometer? Is it goin up quicker than it should or less? Stock tires were 265/70/R17.

If your speedo is showing 6 mph less than actual speed then your odometer will reflect less miles than actual.

So lets say its 64 miles from pointA to PointB according to the raod signs. Then my odometer is gonna show that it was less than that say somethin like 62 miles.

So lets say its 64 miles from pointA to PointB according to the raod signs. Then my odometer is gonna show that it was less than that say somethin like 62 miles.

OK let's try this. You said your speedo is off by 6 mph. With bigger tires it's going to read slower than actual speed. When it reads 60 mph you're actually going 66 mph. Say you drive at 60 mph for 1 hour you actually travel 66 miles but your odometer will only register 60 miles. Bottom line is that your odometer is going to register less miles now with the bigger tires.

Dealer can reprogram for it. Also, handheld & professional tuners