Quote:
Originally Posted by snowbimmer
Wow.
What size tires are you running on your 20" wheels?
Also, if you are OEM everything, and your speedo says 70, we're actually going about 68, right? At least that's what I see when the radar flashes back at me on the highway. So, if you upsize the tires, your speedo under-reports the speed - in other words if your speedo says 70, you're really doing 72. Hence, if BMW calibrates the speedo to be off by 2 mph in the first place, wouldn't a 70 mph speedo on the upsized tires actually now be a true 70 mph? Upsized tires would negate the BMW calibration.
Math is hard. They said there wouldn't be any math.............
|
Winter set: 295/35 R20 & 255/40 R20. Waze shows me moving slower by about 1MPH and Draggy has me moving 1MPH faster then the speedometer.
Summer set: 295/25 R22 & 245/30 R22. This set has me my speedometer at exactly what Waze shows. Not sure as I have not calibrated via Draggy yet. Didn't get the draggy until after I tuned the car in December.