Hey Guys,
I have a question about the tire calc in the speedo section.
If you look at the entered value in my tune which is the same as stock, it shows a value of 24.29. I have change tire size on my car 235/45/17 and the Nitto website says that the tire height is 25.51". I went to Pirelli's website and looked up my factory tire size 205/50/17 and it shows 25.01".
Why would GM have entered the above 24.29 for the tire calc ?
I want to change this to get my speedo reading correctly, at 60mph on the speedo compared to my gps 62-63 mph it is 2-3mph slow.
If I am correct on my thinking that entering 25.51 would make the speedo off by more than what it is now, so I have not done this yet.
Hoping to get some good info from the pros on here before I mess with it.
What do you think ?
Thanks in advance for any input on this subjet.
2007 Pontiac G5 GT.
Attachment 29356