How much is my speedometer off?

Stock size tires are 235/75/17 and the tires on it now are 265/70/17.

How much of a difference in mph does that make and does it make the speed faster or slower?

http://www.bigcustomwheels.com/rt_specs.jsp

“When speedometer reads 60mph (96.6km/h) actual speed will be 61.5mph (99km/h): 2.5% faster.”

Thanks.

When speedometer reads 60mph (96.6km/h) actual speed will be 61.5mph (99km/h): 2.5% faster.

No big deal then. I just noticed how many people were passing me when I set the cruise at 60 in a 55 zone on the northway today.

I cant afford a ticket so Im not going to drive fast thru there because theres usually tons of cops there.