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Swapping From 18's to 20's

GaryT

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I searched but nothing turned up. I have some new 20" take off's for my 19 Big Horn, swapping from 18's. Old tire is 275/65-18, new is 275/55-20. The tire size calculator shows a .2" difference in height, so will I throw any kind of speed mismatch codes or can I bolt these on and go?
 

Scram1500

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The speed mismatch will be minimal, if any at all. No codes will appear, bolt on and enjoy
 

GaryT

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Thanks, thats what I hoped to hear! Apparently the speed difference is .4 mph at 60, I shouldn't even be noticeable.
 

Cryan11

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The tire size calculator has a way to view speed changes. I'm not sure how you get to it but I think it's part of the comparison calculator!

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RJS

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The speed mismatch will be minimal, if any at all. No codes will appear, bolt on and enjoy
Agree, the difference is less than the wear from a new to worn tire.
 

GaryT

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Thanks for the replies, gonna put then on tonight!
 

TVANVA

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I went from stock 18's to aftermarket 20's. According to my GPS, my speedometer now reads about 2 mph slow.
 

GaryT

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Got 'em on, speed appears to be off by 1 mph, I can correct that with AlfaOBD once my security gateway bypass arrives. Ride is a little more firm, but I love the look. Oddly enough, I haven't swapped my TPMS sensors yet, and after a 40 mile ride to work today I didn't get a TPMS system warning. 20200909_175610.jpg
 

bodene

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You had the same question as I did. BTW, you have the same two last cars I've had! What kind of wheels are you using? I'm hoping to use the OEM 20" chrome wheels. Still OK?
Thanks,
bodene
 

Thewrangler73

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You had the same question as I did. BTW, you have the same two last cars I've had! What kind of wheels are you using? I'm hoping to use the OEM 20" chrome wheels. Still OK?
Thanks,
bodene
If you're intrested in a set of chrome 20s i have a set i took off my bighorn.

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GaryT

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You had the same question as I did. BTW, you have the same two last cars I've had! What kind of wheels are you using? I'm hoping to use the OEM 20" chrome wheels. Still OK?
Thanks,
bodene
I went with the OEM 20" brushed aluminum, the tire size should be the same on the chrome clads so you should have the same result. Did you trade your Challenger in on the Ram? I kept mine, still just a nice weather car for me.
 

bodene

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No, the lease was up om the Scat. It sadly had only 3600, yes hundred miles on it. Could kick myself in the butt for not buying it! Had a 2014 Classic RT before the Scat. Thanks for your reply.
bodene
 

bodene

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Yes, I may be interested. I'm not sure how they would arrive here though. I live in PA near Bethlehem.
 

Thewrangler73

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I could find out what shipping costs would be, but probably more than you'd want to pay.

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LakesAZ

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I swapped out my 18" for 20" and have had no problems. My Speedometer is off about 1/2 MPH, so really close enough that I am not going to go the correction route. The ride was slightly firmer, but going from the balloon tires to the lower profile made all the difference in the world when it came to handling. And when I say slightly firmer I mean barely noticeable. I should note that the tires and wheels I took off had less than 600 miles so I went from new tires to new tires, which allowed for a good seat of the pants comparison .
 

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