I own an 05 Silverado 1/2T 2 wheel drive.


It has 18" wheels with large tires. I believe the speedometer is off a little bit.


I am told that the speed cannot be corrected by the computer, that I need an additional electronic control that can be adjusted. Is this correct.
A speedometer shop is the place that told me the above.


What are my options for having the speedometer read the correct speed ???

 

My 2004 Silverado has the same issue. It had 16" tires & rims installed from the factory, but a previous owner replaced them with 17-inchers from a Z-71 Tahoe. My speedometer is 2 - 3 mph off at 60 mph and 3 to 4 mph off at 75 mph. If it indicates me going 60 mph, I am really going 63 and if it indicates 75 mph, I am really going 79 mph. I own a radar gun and have tested my velocity with it, as well as driving with a GPS that indicates my speed continually.


You can either 'live with it' and always be mindful of your speed OR drive with your GPS running -- so as to reduce your chances of getting a ticket for speeding. I suppose you could drop a few large bills on getting it professionally recalibrated.

 

Or for 200$-250$ you can have it tuned for the correct speed and get better performance/mpg out of the truck. Whoever told you it can't be reprogrammed lied through their teeth