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odometer counting to fast

Bully.207

By Bully.207
in Troubleshooting & Recalls

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Terp84Alum Enthusiast

Terp84Alum

Posted
Posted

Yup, the 65 vs 55 is the height which is what will affect the speedometer.

Actually, it's a combination of the 2. 65 and 55 are %.

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Zachlovesfood Enthusiast

Zachlovesfood

Posted
Posted

265 vs 275 are the width of the tires. That wouldn't affect the speedometer, the height would.

If I'm not mistaken, the width affects the height.

For example, 275/55 means the width is 275mm, and the height is 55% of that, which would give you the tire diameter.

So a 285/55 would be slightly taller, since the height is 55% of 285mm, compared to 55% of 275mm.

Daryl LBZ Senior Enthusiast

Daryl LBZ

Posted
Posted

If I'm not mistaken, the width affects the height.

For example, 275/55 means the width is 275mm, and the height is 55% of that, which would give you the tire diameter.

So a 285/55 would be slightly taller, since the height is 55% of 285mm, compared to 55% of 275mm.

I see. I've never had it explained that way to me before. I guess you do learn something new every day.
Zachlovesfood Enthusiast

Zachlovesfood

Posted
Posted

I see. I've never had it explained that way to me before. I guess you do learn something new every day.

Indeed, that's why I like this forum site. Very informative, lots of good stuff on here.

Daryl LBZ Senior Enthusiast

Daryl LBZ

Posted
Posted

Indeed, that's why I like this forum site. Very informative, lots of good stuff on here.

I agree. That, and the atmosphere on here is way better than any other forum I've been on.

HawkeyeSierra Enthusiast

HawkeyeSierra

Posted
Posted

I am really stunned by this. So GM just calibrates the vehicle according to one size then says, "Ah hell, that's close enough" for the other sizes??

 

Can you just take your truck in and have the thing recalibrated to the proper size?

 

BTW: according to www.tiresize.com/calculator

275/55r20 has a diameter of 31.9" and circumference of 100.2"

265/65r18 has a diameter of 31.6" and circumference of 99.1"

 

So aren't you actually traveling further than what the truck itself is figuring, thereby benefiting you? Or am I thinking bass-ackward on this? So confused............

Terp84Alum Enthusiast

Terp84Alum

Posted
Posted

I checked mine using DigiHUD. If I did it correctly, my odometer is high by about 72 ft/mile. That's probably not enough to bitch about.

RhinoGuy Enthusiast

RhinoGuy

Posted
Posted

I am really stunned by this. So GM just calibrates the vehicle according to one size then says, "Ah hell, that's close enough" for the other sizes??

 

Can you just take your truck in and have the thing recalibrated to the proper size?

 

BTW: according to www.tiresize.com/calculator

275/55r20 has a diameter of 31.9" and circumference of 100.2"

265/65r18 has a diameter of 31.6" and circumference of 99.1"

 

So aren't you actually traveling further than what the truck itself is figuring, thereby benefiting you? Or am I thinking bass-ackward on this? So confused............

Taller tires should make your truck show less miles than you are actually putting on it. Unless you have the vehicle calibrated.
SouthernSilveradoGuy85 Senior Enthusiast

SouthernSilveradoGuy85

Posted
Posted

I am really stunned by this. So GM just calibrates the vehicle according to one size then says, "Ah hell, that's close enough" for the other sizes??

 

Can you just take your truck in and have the thing recalibrated to the proper size?

 

BTW: according to www.tiresize.com/calculator

275/55r20 has a diameter of 31.9" and circumference of 100.2"

265/65r18 has a diameter of 31.6" and circumference of 99.1"

 

So aren't you actually traveling further than what the truck itself is figuring, thereby benefiting you? Or am I thinking bass-ackward on this? So confused............

 

 

Taller tires should make your truck show less miles than you are actually putting on it. Unless you have the vehicle calibrated.

 

 

A taller tire will go further in 1 revolution so if it's not calibrated the truck actually goes further. So I agree with Hawk. If you put 2 tires with different heights beside each other and put a mark on the sidewall of each and roll them so the mark does 1 revolution the taller tire will go further. So that means the truck actually has more miles on it than the odometer shows. At least that's how I'm thinking, if I'm wrong please show me how I'm wrong.

RhinoGuy Enthusiast

RhinoGuy

Posted
Posted

 

 

 

 

A taller tire will go further in 1 revolution so if it's not calibrated the truck actually goes further. So I agree with Hawk. If you put 2 tires with different heights beside each other and put a mark on the sidewall of each and roll them so the mark does 1 revolution the taller tire will go further. So that means the truck actually has more miles on it than the odometer shows. At least that's how I'm thinking, if I'm wrong please show me how I'm wrong.

Correct. The truck is traveling farther than what the truck computer is logging.

 

Using Hawks tire sizes, you would travel roughly 1" farther per rotation when using the 275/55/20.

 

476d14d4d5fe6bcbeafc20c8c69fb200.jpg

RhinoGuy Enthusiast

RhinoGuy

Posted
Posted

Using Hawks posted tire sizes as an example here.

 

275/55/20 will travel roughly 7" farther per truck computer mile than what the 265/65/18 will.

Silverado4x4 Senior Enthusiast

Silverado4x4

Posted
Posted

I would like to know how you are measuring a mile? I hope your not using mile makers on the highway because there not to the exact mile and GPS is also not to the exact mile. No speedometer is going to be dead on to the mile.

Bully.207 Enthusiast

Bully.207

Posted
  • Author
Posted

That's exactly what I've been using mile markers on the turnpike I work on the turnpike I know they're pretty close I checked about 10 different spots they all come up the same about 270 feet off the GPS says the same checked with wife's car comes up the same pretty sure it's off but I have a measuring wheel and I will confirm with the wheel thanks for everyone's input I'll let you know what the dealer says

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