Need all the car nuts help.

[JacobEXE]

i have 15's on my truck now, my friend is giving me a pair of 17's with new tires on them..
i was told if i went up on rim and tire size that it would mess with my gearing, my speedometer, my odometer and a whole bunch of other stuff is this true? if so is there any way to calibrate my odometer & speedometer so that is gives the correct reading?

 

[HT413]

Rim size has nothing to do with it. Post the diameter of the old tires and the new tires and we can tell you what the effect will be. Couple inches bigger wont be a problem but if you try to go to a 33" or even a 31" you might make that little 4 banger a real dog.

Here's the calculation: take the mph at a given rpm and multiply by new tire diameter then divide by old tire diameter to get new speed at a given rpm. OR, take the RPM and multiply x old tire diameter and divide by new tire diameter to get the new rpm you'll be at at a given mph.

 

[RustyRatRod]

how in the world are we supposed to tell you how to correct your speedometer if we don't even know what year or kinda truck you have?

 

[JacobEXE]

how in the world are we supposed to tell you how to correct your speedometer if we don't even know what year or kinda truck you have?

96 ford ranger 2wd 4cyl

 

[RustyRatRod]

Manual or auto? My crystal ball is broke. At any rate, that speedometer is electronic, I believe and will require a computer reflash to get it right.

 

[Jasoncoronet]

Yes you may able to get a progamer for that year. Usually there will be a option in the programmer for tire diameter which will fix your speedo and odometer issue. Try hypertech, diablo there is a whole bunch of makers out there.

 

[Cranky]

If you have tires that's 26" in diameter and you increase it by 10% or to a 28 1/2" or so then yeah, you'll notice that your speedometer is off by roughly 10% slow. That's roughly the same as going from a 3.50 gear to a 3.15 rear end gear. You'll notice that with a 4 banger for sure....

 

[JacobEXE]

Manual or auto? My crystal ball is broke. At any rate, that speedometer is electronic, I believe and will require a computer reflash to get it right.

manual

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If you have tires that's 26" in diameter and you increase it by 10% or to a 28 1/2" or so then yeah, you'll notice that your speedometer is off by roughly 10% slow. That's roughly the same as going from a 3.50 gear to a 3.15 rear end gear. You'll notice that with a 4 banger for sure....

i dont know if i wanna change them anymore ha! but i need tires so ill go talk to our local mechanic tommorrow and seee what he says

 

[rsd859]

Whats a speedometer?

 

[RustyRatRod]

Yes you may able to get a progamer for that year. Usually there will be a option in the programmer for tire diameter which will fix your speedo and odometer issue. Try hypertech, diablo there is a whole bunch of makers out there.

Oh yeah. Run right out and get a programmer for 400 bucks just to reprogram the speedometer. Why didn't I think of that?

 

[HT413]

Well, what size are the new tires? F the damn speedo, bro, a nice 31" tire will dramatically improve the off road ability of that little Ranger. So you have to gear down when cruising around town, who cares? Unless you do a lot of highway driving, I'd consider the swap.

 

[JacobEXE]

Well, what size are the new tires? F the damn speedo, bro, a nice 31" tire will dramatically improve the off road ability of that little Ranger. So you have to gear down when cruising around town, who cares? Unless you do a lot of highway driving, I'd consider the swap.

im not sure on the tire size yet. im still waiting on them. the speedo will cost me $40 to get calibrated no big deal. highway, what the hell is that? haha ialways drive the backroads to get it sideways.

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Whats a speedometer?

some thing fords come with, i dont know why though its not like i could speed in it!

 

[65 Plymouth Satellite 426]

My Damn Speedometer Hasn't Worked In Years!