Ok, My speedometer is about 4 mph off. When I go 40mph, I'm actually going 36mph.
I've gotten this confirmed by pacing a 2002 Acura RSX, and by a laser gun from a cop, after I showed concern about my speedo(after he gave me a ticket)
How do I fix this, or how much would it cost to fix? How invasive is it?(hopefully no deep surgery on my baby
)