Has anyone re-calibrated their speedometer/odometer after changing wheel/tire size? I am slightly concerned by the fact that the speedometer will read below my actual speed. Odometer is less of a concern as it should count less miles than reality.

Now that I think about it, changing wheel size probably also messes with fuel efficiency and range calculations, too.

Anyway, would a dealer need to do this, or is there an easy way?

I have a 2015 RC 350 AWD F-sport. I am thinking of possibly up-sizing the wheels from 19" to 20".

 

I am running on 20's and my spedo is dead on. Tested with GPS speedbox. I really dont think it is necessary

 

I'm on 20s. For cars like ours, speedometer really won't vary much so you don't need to re-calibrate.

If you had a truck and got bigger wheels and tires, then yes, you'd definitely have to re-calibrate. All of my cars have had aftermarket wheels going up a 1 or 2 inches, never had to re-calibrate. If you're going up 2 inches or more, you'll definitely want to put hub centric rings.

 

^^^^Whether your on 18s, 19s, or 20s doesn't really matter if your tire selection is correct. By correctly managing aspect ratios and tire width, the OD (outer diameter) of the wheel tire combo should be the same or very close to the stock OD with a new wheel/tire combo.

Lou

 

Does anyone have any insight on daily driving with 20" wheels? I would really like to have 20" but am a bit concerned with the roads in NJ.

Am I likely to destroy the new tires/wheels? Does the ride comfort change significantly?

 

I run 20"s on my daily. Ride comfort is unchanged IMHO. As for destroying your wheels/tires that all depends on your roads and how you drive on them. Luckily I have pretty decent roads where I live and I know the roads which I frequently drive on so I am able to avoid potholes, etc. Very rarely do I hit a pothole but so far have not bent a wheel nor damaged a tire.