If my speedometer reads 72 while driving 65 mph will this in

If my speedometer reads 72 while driving 65 mph will this influence the vehicle's odometer reading?
Will this because me to rack up more miles than I have really driven?

Yes it'll show more miles. The extra miles will be the same % as the speed inaccuracy.

So going 65 miles will register as 72 miles.

no your speedometers wrong

will driving 20mph instead of 55 save you miles on your car?

yes, you'll have to use a minus 11% correction to your mileage.

Of course it'll. In newer cars TPC or tire performance requirements diameter is really noted in tire catalogs. This may also effect rear pipe emissions.

In older cars you may be able to easily get this fixed by installing a special little gear percentage adapter in the speedometer cable.

I really beat a speeding ticket on one occasion after changing the ring and pinion in my truck, this threw off the speedometer. Of course it only worked that one time, after to get the problem corrected things were again as they should be.

yes, this will effect the odometer, just that seven mile per hour variance over the life span of the car will be tremendous.
if you drive 65000 miles, and the odometer reads 72000, that will effect the value, right?
this may be caused by tires that stand taller than the originals, a mis calibrated speedometer drive gear percentage. I could recommend that you take it to a shop and have the problem remedied quickly.

Of course it'll.