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Tini Tini Bo Bini
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Discussion Starter · #1 ·
anyone have any idea why my speedo reads 2mph faster than im really going? Im on stock tires (235-55-zr17)and stock gears (3.31s as far as i know. i got the car used). Ive checked against multiple GPSs. anyone have any insight?
 

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I was going to ask the same question. I have a 5 spd with 3.55 gears and according to my GPS my speedo is off about 2 mph.
 

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How are you figuring that? It's only 2 MPH. does it matter?
 

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Your Mom's Favorite
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You could change it with a handheld, but then your odometer would be off. Don't lose any sleep over it. My F150 does the same thing. I set tire size based on the accuracy of the odometer because the speedo isn't accurate. Either Ford did that because they love their customers so much that they don't want us to get speeding tickets, or it's an easy way to fudge a little more fuel ecomony out of the car for an indicated m.p.h. Who knows?
 

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Tini Tini Bo Bini
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Discussion Starter · #7 ·
How are you figuring that? It's only 2 MPH. does it matter?
yeah. there are asshole cops that will pull you over for doing 1 over. i was in court when the cop was getting his MOTHER for speeding. its just kindof annoying that when i hit cruise contriol i have to guestimate my speed
 

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Your Mom's Favorite
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yeah. there are asshole cops that will pull you over for doing 1 over. i was in court when the cop was getting his MOTHER for speeding. its just kindof annoying that when i hit cruise contriol i have to guestimate my speed
So...you're indicating 2 m.p.h. slower than you're actually going? Hmm...usually they indicate 2 m.p.h. fast, so you're actually going slower than indicated...


EDIT: As far as a cop pulling you over for 1 over...that's easily defeatable in court because there is no way to make a spedometer absolutely perfect. Hell, your speed changes just from driving on the tires as they warm up...there is a couple m.p.h. range that manufacturers are supposed to be within, that's it. Never mind the differences in tire height for the numerically same size tire from 2 different manufacturers. That cop would be a ****ing idiot. Is there even a box on a speeding ticket for less than 5 over?!
 

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Priest of the Car Gods
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A ticket for 1 over will always get thrown out in court - the methods for determining your speed, including the vehicle's own speedometer, just aren't accurate enough to prove guilt.

I understand it's a pain to get pulled over, but if you're consistently getting nailed for 1 or 2 over, I'd be documenting every event and suing the department for harassment.
 

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So...you're indicating 2 m.p.h. slower than you're actually going? Hmm...usually they indicate 2 m.p.h. fast, so you're actually going slower than indicated...
Hmm, that's not what the first post says but I see where you're saying that.
 

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Sometimes, when I'm on the freeway it seems like I'm going really, really fast............


































Then I look down at my speedo and it says 50 mph.
 

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Tini Tini Bo Bini
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Discussion Starter · #12 ·
So...you're indicating 2 m.p.h. slower than you're actually going? Hmm...usually they indicate 2 m.p.h. fast, so you're actually going slower than indicated...


EDIT: As far as a cop pulling you over for 1 over...that's easily defeatable in court because there is no way to make a spedometer absolutely perfect. Hell, your speed changes just from driving on the tires as they warm up...there is a couple m.p.h. range that manufacturers are supposed to be within, that's it. Never mind the differences in tire height for the numerically same size tire from 2 different manufacturers. That cop would be a ****ing idiot. Is there even a box on a speeding ticket for less than 5 over?!
it shows me as going faster. I'm just saying if its not accurate, how do i know im not setting my cruise control too high? it kinda made sense in my head LOL. beleive it or not those tickets get through the court system. its how this peice of **** city gets all their money.
 

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hmm not that it bothers me but I will have to check that in my F150
 

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Just FYI.... here in Georgia there are only 3 ways to recieve a speeding ticket for doing less than 10 over. (this is what we learned in police academy)

1. By Georgia State Patrol
2. In a school or work zone
3. In any area that says "speed limit strictly enforced" i.e. a school/work zone.

99 out of 100 times anything less will be laughed out of court.
 
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