Tires

[Archive]

I just put new tires on, LT265/75-R16.
How much will the odometer be off with this larger size tire.

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95 3/4 4x4 5 Spd K&N Air Filter 93,000
Ride Rite Air Overloads
10 1/2 Cabover Camper

 

[Archive]

Well at when my mph says 30 I'm actually doing 28.
I got a ticket a couple years ago for doing 70 in a 55 zone. My mph was 70.
So at least on mine its where it should be. The truck came with 245 at least thats what it says on the sticker. I have always run 265/75 since I have owned it

 

[Archive]

It will throw off your odometer mileage slightly. I have a vehicle,that was shipped with the 245's. It has 265's now so when it shows I traveled a mile I actually only went 9 1/2 tenth's of a mile. So the way I got it figured,when I show 20 miles on the trip odometer,I actually went 21. Makes a difference when your checking MPG.

 

[Archive]

Thanks for the replies, that is about the way I had it figured. it is at 98000 now so I have to change my signature block.

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95 3/4 4x4 5 Spd K&N Air Filter 93,000
Ride Rite Air Overloads
10 1/2 Cabover Camper

 

[Archive]

I found this website that calculates the difference in the tire sizes. http://pw1.netcom.com/~sgalaba/tiresize.htm
I also run the 265's now. It says that there is a 3. 88% difference in the speedometer. That helps when I calculate the fuel mileage on my truck. I just add the 3. 88% to the miles on my trip odometer and use that number to figure my mileage.

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1994 Ram 2500 Laramie SLT, Cummins turbo diesel, 2WD, Automatic(beefed up after a few rebuilds) Ranch Hand steel brush guard, Westin Step bars. sprayed in liner. silencer ring removed, Flowmaster muffler, chrome turn down pipe out the side, Velvet ride shackles. www.gitchesumatfreeweb.com

[This message has been edited by gitchesum (edited 07-09-2000). ]

 

[Archive]

I think it is a one tooth in the speedo drive pinion correction. (4%)

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"Roadrunner"-96 4X4 club cab-12v-auto-3. 54 gears-Amsoil bypass filter - all Amsoil fluids-trans filter-britebox-shelfit-DeeZee boards-Rhino liner-Rancho 5 speed shocks-Hellwig rear antisway & overload springs-Warn 12000 lb. winch-dual redtop optimas-combo gauge and trans. temp gauge in pillar mount-255/85R16 Kelly MSR tires-custom pinstriping- Walker muffler-Cummins mudflaps-Tuff Country control arms-2" coil spacers

 

[Archive]

I'm going to move this over to the chassis forum.

Thanks for participating.

Mark

 

[Archive]

Ray,

If you went from 245's to 265's, your speedometer would be lower than your actual speed. When indicating 55. 6, you would be going 60. 0

Mick2500

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2001 2500 ETH/DEE, QuadCab, 4X4, SB, LSD, 3. 54, SLT+, Sport, Intense Blue PC/Agate, Tow Package, Camper Package, 'DC' Bed Cover, Sliding rear window. Ordered 5/01/00... Cancelled 5/30/00... re-ordered 6/02/00... Cancelled again by DC 6/05/00
Gauges (EGT/Boost) and A-Pillar mount Here, 4" Exhaust, Here.
UPDATE!! Re-ordered 7/7/00..... Finally a new VON, Status BX 7/11/00

 

[Archive]

Generally, all aforementioned information holds true.

I saw posted somewhere an LT245 that was just as tall as a competitor's LT265. Or that may have been the LT265 was just as short as the LT245.

It's best to measure the diameter and then do the computations.

Whatever, a taller tire than the original installed tire will make the speedo read slower.

On my Z71, I went from a 3. 42 gear to a 4. 10 and then from LT265 to LT285 tires. What would my speedo read then? I gave up and traded the truck off! Actually, I reprogrammed the computer ($275) for the new gear ratio and the tire diameter and then traded the truck off!

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"Red Rage" - 2001 2500 SLT 4x4 QC Lowered Rear End 2. 5" 5spd, 4. 10 K&N Stock Replacement - 9,000 miles and counting! 30' 5th Wheel

[This message has been edited by bennettj (edited 07-11-2000). ]

 

[Archive]

I just calculated the difference between the 245/75R16s that came stock (actual height 31") and my new 35x13. 50R16s (actual height 34. 5") and found that at 65 MPH my speedo will actually read 57. 2 MPH, a difference of almost 8 MPH. Question... how do I calculate the odometer discrepancy?

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Y2K 2500 4X4 5-spd Reg cab
Dark Garnet Red
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Already added:
Blaupunkt AM/FM Cass. & 12 CD Changer, Diamondplate running boards, Clearance and Tailgate I. D. lights
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Being shipped to me right now:
35x13. 50R16 M/T Baja Claws, 16x8 black Rockcrawler wheels, 2" Daystar Front Coil Spacers, Bushwhacker Extend-a-Fender flares.
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In the future:
A big honkin' chrome rollbar!!!! Oh, and more power too!

 

[Archive]

DixieDawg ----

All new readings on the odometer should be multiplied by 1. 136364.

If your odometer shows that you have traveled 100 miles, you have actually traveled 113. 6364 miles.

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"Red Rage" - 2001 2500 SLT 4x4 QC Lowered Rear End 2. 5" 5spd, 4. 10 K&N Stock Replacement - 9,000 miles and counting! 30' 5th Wheel

[This message has been edited by bennettj (edited 07-12-2000). ]

 

[Archive]

Is this an issue with Rickson's (19. 5") or do they work some voodoo on the speedo to correct for the larger tires?



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Eric Schultz
2000 RAM 2500 w/Cummins
QuadCab SLT Plus
Medium Bronze Pearl Coat
Stainless SmittyBilt Nerf Bars, flaps, X-Tang tonneau cover & Rhino bed liner

 

[Archive]

Eric - Yes, the big diameter wheels will affect both you engine RPMs and your speedo readouts. A friend just put 285/75-16s on his truck, and he got the speedo recalibrated (a computer setting on the newer trucks) for $30. Check under "Speedometers" in your yellow pages for a local shop that can do this.

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Wait'n for my 2001 2500 QC, SB, 4x4, ETH 6-sp, 3. 54 LSD, SLT++ (everything but those silly looking lights on top of the roof), White over Silver, Tan leather.

 

[Archive]

A good way to figure out the difference in speed is to go to a website like B. F. Goodrich or Dunlop and record the 'revolutions per mile' of your new tire size vs. the OEM tire size. The ratio of the bigger number to the smaller number will tell you how much faster you are going. For instance, my stock Goodyears 245/75s were 683 rev/mi and my Dunlop 255/85s are 626 rev/mi, so 683/626= 1. 091, or 9. 1% increase. I did not recalibrate my speedo; I just add 10% in my head to figure speed while driving, and multiply miles by 1. 091 when figuring mileage at the pump.

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1998. 5 BE7L33 4x4, NV4500HD, 3. 54s, 255/85-16 Mud Rovers, Cummins uprate kit

[This message has been edited by Craig DeYoung (edited 07-12-2000). ]