Changing to 20" wheels, speedo issues?

[1500BR]

Hey guys quick question. My 2010 Ram quad cab has the stock 17" wheels. I am looking to swap them out with a set of Stock 20" wheels from my buddies 2010 Ram big horn edition.

Anyhow, I just wanted to know if doing this will affect anything like odometer / speedometer input. Would I need to get it re tuned at the dealer?

Any advice appreciated, thanks!

 

[cyclepuck]

Depends on tire size. If the overall height of the tire is the same or real close there won't be any change.

 

[14hemiexpress]

I'm pretty sure it's going to trow off the speedometer it did on my 06 when I went from the factory 17-20s easy fix you have 3 options. 1 go to the dealer and have it re flashed. 2 buy a hand held tire size changer about $250. 3 get a tuner. All work great dealer is cheepest but it's a 1 time use. If you get the hand held that's just for tires you can change tire size as much as you want but that's all it does. And a tuner well we all know what that does

 

[BlackRamHemi]

no change required at all, if tire diameter is similar


I don't know why people would think the wheel size changes anything,
unless they are driving without tires on them

only the tire diameter can effect the speedo/odo reading

http://tire-size-conversion.com/tire-size-comparison/







There's a LOT of tires that measure approximately 33" tall
as you can see the wheel size doesn't really make a difference...



Also, most speedometers read too fast from the factory,
a slightly larger diameter tire often corrects the error.

 

[Jerry1984]

All depends on tire sizes as stated above.

 

[BlackWidow]

no change required at all, if tire diameter is similar


I don't know why people would think the wheel size changes anything,
unless they are driving without tires on them

only the tire diameter can effect the speedo/odo reading

Tire Size Comparison







There's a LOT of tires that measure approximately 33" tall
as you can see the wheel size doesn't really make a difference...



Also, most speedometers read too fast from the factory,
a slightly larger diameter tire often corrects the error.

^^^^This

Doesn't what rim size you choose if the new tire size (diameter) is equal to what is being replaced.

 

[HemiRoar]

i switched from the stock 31.5" tire to 33" tires. speedometer wasn't really off when driving alongside buddies.

But since i have a trinity, i updated the tire size anyway.

 

[14hemiexpress]

Factory tire size is a 265/70r17 is a 31.6 tire vs the 275/60r20 witch is 33 it is a difference of 4.4% at 60 you will really be doing 63... So it's not the end of the world but from my own personal experience your truck will be very touchy with overdrive. Barley touch the gas pedal on the highway it'll kick it out of OD. I recomend updatedateing the tire size it'll keep the computer happy.

 

[steadly2004]

no change required at all, if tire diameter is similar


I don't know why people would think the wheel size changes anything,
unless they are driving without tires on them

only the tire diameter can effect the speedo/odo reading

http://tire-size-conversion.com/tire-size-comparison/







There's a LOT of tires that measure approximately 33" tall
as you can see the wheel size doesn't really make a difference...



Also, most speedometers read too fast from the factory,
a slightly larger diameter tire often corrects the error.

This is absolutely incorrect, The tire pressure sensors also are used in abs and traction control ssystem switching from 17 to 20 inch wheels seemed fine at first. Then a week later my abs would kick in with light braking and it was a very dangerous situation. Wheel diameter was set with the tuner. Switching tire sizes can be fixed with a tuner. Wheel sizes can't as far as I know, and must if you want to be able to stop. Also the abs light came on. Fix was to have the dealership flash for 20's.

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[BlackRamHemi]

This is absolutely incorrect, The tire pressure sensors also are used in abs and traction control ssystem switching from 17 to 20 inch wheels seemed fine at first. Then a week later my abs would kick in with light braking and it was a very dangerous situation. Wheel diameter was set with the tuner. Switching tire sizes can be fixed with a tuner. Wheel sizes can't as far as I know, and must if you want to be able to stop. Also the abs light came on. Fix was to have the dealership flash for 20's.

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Tire pressure sensors have ZERO to do with ABS or tire speed
TPMS sensors use a 433hz radio signal to send pressure information only
There are ABS speed sensors on each front hub that are hardwired to count hub rotation speed only.
and an ABS Tone ring in the Rear Differential, neither knows or cares
what size wheels or are on your truck, it counts the electro-magnetic pulses as the carrier turns. period.



I have three sets of tires/wheels, 17's and 20's, some don't even have TPMS sensors
If what you said was true for every Ram my truck would be undriveable without a dealership flash each time I changed tires/wheels.

 

[steadly2004]

There is a sensor there, but it's not the only sensor used. We (the dealership) replaced that first but the problem was still there.

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[BlackRamHemi]

There are ABS speed sensors in the front hubs that monitors hub rotations,
but it sure as heck is not in the tire pressure sensor, and doesn't know or care what the wheel diameter is.

Here's a pic of my drivers side front wheel well,
the rubber sleeved line contains the ABS hard wired signal from the hub.
The little white push plug releases the connector so you can unplug the ABS sensor.



I've done this several times to manually disable ABS/ESP and traction control at the track for drag racing
and for dyno testing/tuning sessions with my local CMR.





17's or 20's make no difference to my ABS system at all

 

[steadly2004]

I'm saying it happened to me. Whether you believe it or not, lol. Have you ever changed wheel sizes 3" ?

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[BlackRamHemi]

I'm saying it happened to me. Whether you believe it or not, lol. Have you ever changed wheel sizes 3" ?

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see post above

I have three sets of tires/wheels, 17's and 20's, some don't even have TPMS sensors
If what you said was true for every Ram my truck would be undriveable with no sensors registering a signal.

 

[steadly2004]

Took about a week or two for mine to wig out. Did you keep them on for a week? Or just track day?

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[BlackRamHemi]

There is a sensor there, but it's not the only sensor used. We (the dealership) replaced that first but the problem was still there.

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We the dealership LOL!

that explain everything, nuff said

 

[steadly2004]

We the dealership LOL!

that explain everything, nuff said

Lol. I'm not from the dealership, lol. I just took it there when the local shop couldn't help. I just meant to point out the sensor was replaced but the problem persisted.

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[BlackRamHemi]

Took about a week or two for mine to wig out. Did you keep them on for a week? Or just track day?

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They are street legal DOT drag radials, left them on for a whole month once...


Do realize how many peeps run aftermarket wheels without TPMS sensors?

 

[steadly2004]

Yea. No sensor is very different than sensor in a different size wheel. Are there sensors in those wheels? I bet not. You don't have to believe it happened to me. I have nothing to prove. But.... it happened.

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[jwheeler]

This is absolutely incorrect, The tire pressure sensors also are used in abs and traction control ssystem switching from 17 to 20 inch wheels seemed fine at first. Then a week later my abs would kick in with light braking and it was a very dangerous situation. Wheel diameter was set with the tuner. Switching tire sizes can be fixed with a tuner. Wheel sizes can't as far as I know, and must if you want to be able to stop. Also the abs light came on. Fix was to have the dealership flash for 20's.

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You are way off base. Tire pressure sensors are for tire pressure. Nothing else. Wheel size does not matter at all. The over all tire diameter is what matters for abs and traction control. Don't know what your dealer told you but I have worked at a ram dealer for 5 years.