Does moving from 22" to 20" wheels impact speedometer?

[Its_Shaun12]

Wow... that is a large change! Is there anything else you.may have done to alter the numbers?

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[wjburken]

I did the same on my rig and its roughly 6 MPH slow when going 65 and 9 difference when doing 70

First off, welcome to the forum.

Can you please explain what changes you made to your tires to get a 10% -/+ error between actual speed vs speedometer reading?

To get that much of a difference in measured/actual speed, your tire diameter would have had to have been changed by approx 3”, either up or down, if your stock tire size was 285/45R22

 

[sealandsky]

I really don't like the ride of my Yukon Denali with 22" wheels. I am considering buying a set of 20" take-offs from eBay. If I do, will affect my speedometer significantly and would I need to have the ECM reprogrammed?

thanks,
Dennis

I can't tell what year your Yukon is, but if it's not a 2019 or newer then I'd suggest you go to your dealer and request that they update your ride control software with the latest version. My 2019 with 22" wheels rides better than my previous 2016 with 20" wheels did. Also, your tire brand / model will make a difference - I'd suggest Michelin Premier's.

 

[91RS]

The 285/45/22 is 0.2" taller than the 275/55/20 so the speedometer and odometer will be off by 0.6%. It isn't huge but I'd still want it corrected because I'm a perfectionist.

Now, the thing is depending on the year of your truck this may not fix squat. This body style is very very sensitive to tire roundness and most tire places do not have a roadforce tire balancer and even fewer know how to use it to help fix the tires (meaning you don't just spin up the tire and it magically fixes it). If you have a 16 or older, it also likely has the original design steering gear bushings. I would highly suggest Michelin Defender LTX tires and the new steering gear bushings depending in the year of your truck and you'll probably be happy with it after that.

 

[SSpinball]

I find the ride of the lower profile 45 series to be too harsh. Before this I had a Tahoe with 20”wheels and the ride was much better.

I went from 275-55/20 from 285-50/20. about 2 mph difference.