Tire size: Speedometer results question

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  #16  
Old 03-23-2009, 11:43 AM
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I have always been curious why the Ford speedo is 2 mph fast. Might be to eliminate any lawsuits from customers that get speeding tickets, claiming the speedo was slow. I'm sure the fact that the warranty runs out quicker is not a factor. They wouldn't do that!
 
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Old 03-23-2009, 12:25 PM
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Originally Posted by jimmyv13
I failed to mention my 20 wheels have 35's on them and they wouldn't/couldn't calibrate it. Obviously, much bigger than stock. I really didn't care, the truck was not at the dealership for that, but the tech thought he's be nice and calibrate the PCM, but found out he couldn't. And, with the Edge and GPS, I know how fast I'm going.
they can recalibrate 35's. the guy who helped me do mine recalibrated his own ( he has 35's)

it can be done, just takes some work.

have you guys noticed that the edge makes your tranny slip or anything? it did on my powerstroke before i beefed up the tranny. how much horsepower gain did you notice? and can you still run 87 octane gas?




(sorry Op for getting off topic)
 
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Old 03-23-2009, 12:30 PM
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Originally Posted by RJcavF150
they can recalibrate 35's. the guy who helped me do mine recalibrated his own ( he has 35's)

it can be done, just takes some work.

Fookin' lazy techs.
 
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Old 03-23-2009, 12:30 PM
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Originally Posted by RJcavF150
they can recalibrate 35's. the guy who helped me do mine recalibrated his own ( he has 35's)

it can be done, just takes some work.

have you guys noticed that the edge makes your tranny slip or anything? it did on my powerstroke before i beefed up the tranny. how much horsepower gain did you notice? and can you still run 87 octane gas?




(sorry Op for getting off topic)
My tranny has been fine. I put 31,000 on the Edge, then got the Gryphon custom tunes and have 21,000 on them. No problems at all. On the Edge, you use 87 on the towing tune and the sfift tue. You use 91 or 93 on the performance tune. For the Gryphon custom tune, you can get it progarmmed however you want it. I have an 87 Performance tune and a 93 Performance tune. If you are considering an Edge, I highly reccomend going for the Gryphon. Same hardware, same canned tunes, but comes with the custom tunes that are much better.
 
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Old 03-23-2009, 12:33 PM
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Originally Posted by Bluejay
My tranny has been fine. I put 31,000 on the Edge, then got the Gryphon custom tunes and have 21,000 on them. No problems at all. On the Edge, you use 87 on the towing tune and the sfift tue. You use 91 or 93 on the performance tune. For the Gryphon custom tune, you can get it progarmmed however you want it. I have an 87 Performance tune and a 93 Performance tune. If you are considering an Edge, I highly reccomend going for the Gryphon. Same hardware, same canned tunes, but comes with the custom tunes that are much better.
lol thats what i read in all the posts about chips, but i have no idea where to find one. or what tunes i want lol.
 
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Old 03-23-2009, 12:36 PM
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Originally Posted by RJcavF150
lol thats what i read in all the posts about chips, but i have no idea where to find one. or what tunes i want lol.
Here is where you get the Gryphon. www.powerhungryperformance.com. If you are not interested in the momitor/gauges that the Edge or Gryphon offers, then the Xcal3 tuned by Troyer Performance is a great programmer.
 
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Old 03-23-2009, 12:49 PM
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Getting my speedo reset wed morning. They quoted me $104 .
 
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Old 03-23-2009, 03:50 PM
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Duplicate post
 

Last edited by cstanek; 03-23-2009 at 03:52 PM.
  #24  
Old 03-23-2009, 03:51 PM
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Originally Posted by Bluejay
It's a good excuse to get a tuner so you can get it accurate yourself. The money you pay the dealer is like a downpayment on the tuner.
My thoughts exactly. At $100 a pop, you might as well just get a tuner. If you change tire size five times, you've already paid for an Edge or a Gryphon.

Before I put on larger tires, I figured out how close the Edge and speedo were to the GPS. (Edge was dead on and the speedo read 1 MPH less, by the way.) Once I put on larger tires, I reprogrammed the Edge with the tire size from the Edge manual. It still wasn't quite on, so I kept adjusting it, lowering it 10-25 mm each time until the Edge and Garmin matched up again. I know I was overly **** about it, but that's how I am.
 
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Old 03-23-2009, 03:54 PM
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Originally Posted by Bluejay
I have always been curious why the Ford speedo is 2 mph fast. Might be to eliminate any lawsuits from customers that get speeding tickets, claiming the speedo was slow. I'm sure the fact that the warranty runs out quicker is not a factor. They wouldn't do that!
Does the odometer actually run up faster, or did Ford make the odometer slow down to compensate for the discrepancy in the speedo?
 
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Old 03-23-2009, 03:58 PM
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Originally Posted by cstanek
Does the odometer actually run up faster, or did Ford make the odometer slow down to compensate for the discrepancy in the speedo?
I know that on the mechanical, the odometer and speedometer are using the same gear. On the computerized, I do not know. I just assumed they used the same sensor. If someone knows for sure, maybe they will speak up.
 
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Old 03-23-2009, 05:41 PM
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Originally Posted by TJ05FX4
You are wrong in thinking that it will be off different percentages at different speeds. If its off 10% at 20mph, its off 10% at 80mph too. Your tires don't change size as you go faster or slower, so you aren't going to have varying results
actually you are wrong there. your speedometer will be off more the faster you go.
 
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Old 03-23-2009, 05:43 PM
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Originally Posted by dilloncawthon
actually you are wrong there. your speedometer will be off more the faster you go.
That is what he said. More mph, but the same percentage.
 
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Old 03-23-2009, 05:44 PM
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Originally Posted by dilloncawthon
actually you are wrong there. your speedometer will be off more the faster you go.
no, it'll be the same percentage, just a higher speed.

like if it's 10 percent too fast 88 would actually be 80, but 77 would actually be 70 ( i may have reversed that)

i duno, im terrible at math, but yea, percentage stays the same throughout, numbers don't.

i probably just confused you all even more. haha

this calls for the new smily we got

 
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Old 03-23-2009, 05:49 PM
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whoops, okay i gotcha. yeah i thought he was saying the number of mph off would stay the same. yep the percentage would haha llama
 


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