How do you tell if your speedometer is off? I was driving next to my friend on the highway and the speed limit was 65. and i was doing 75 and he said his speedometer was at 65. And we were right next to each other. So how can i tell if my speedometer is off or not? I have a stock ej2.

 

What size tires does your friend have? (ie aftermarket, larger than stock rims)

 

He was drivining a Buick Century. And yes it was all stock.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1995Civiccx &raquo;</TD></TR><TR><TD CLASS="quote">How do you tell if your speedometer is off? I was driving next to my friend on the highway and the speed limit was 65. and i was doing 75 and he said his speedometer was at 65. And we were right next to each other. So how can i tell if my speedometer is off or not? I have a stock ej2. </TD></TR></TABLE>

Fly your *** pass one of those radar trailers the cops have.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dr92cx &raquo;</TD></TR><TR><TD CLASS="quote">

Fly your *** pass one of those radar trailers the cops have.</TD></TR></TABLE>

that's what I do every day on the way to school lol, my speedometer is off by around 4 MPH haha

 

Lol they dont have those by my school. They just clock people now a days. And when they do have the trailers the cops are always next to them on their bikes or in their cars.

 

ask the cop to clock you while you drive down the road at a constant rate of 50mph(according to your speedometer) or whatever the speed limit may be and then after that ask him what he clocked you going as, problem solved lol, also a good way to make friends with some of the local cops haha

 

Nobody said you have to break the speed limit past the trailer, doing the speed limit is just as good.

You could go on the highway, set your cruise at 60mph, and start a stopwatch when you pass a mile marker, then stop it when you reach the next mile marker. There's a formula you can use to take the time elapsed & distance traveled to work out how fast you're going. I just... can't find the formula right now...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MonkeyBoy668 &raquo;</TD></TR><TR><TD CLASS="quote">There's a formula you can use to take the time elapsed & distance traveled to work out how fast you're going. I just... can't find the formula right now...</TD></TR></TABLE>

Rate = distance/time ?

60 mph = 1 mile in 1 minute. Start from there.

 

Damn youse!

Actually I remember the equation being a lot more complicated. But... maybe it was a math geek expressing a math joke...

 

ok, but who do you trust......

the odometer or the state mile markers??????

on MY car using standard size 175/70/13's odometer was 2.5 % off, speedo was 4.5% off.......using standard TSD calculations.

Running fresh 185/65/14 and the speedo is dead on, mileage is readind low by about 2%....considering I drive 120 miles a day for work, easy to notice.

One also must consider just how much tire OD changes from new to worn out.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mista Bone &raquo;</TD></TR><TR><TD CLASS="quote">ok, but who do you trust......

the odometer or the state mile markers??????
</TD></TR></TABLE>

Mile markers. Odo gets the same data that the speedo does....

 

those have been known to be off also.........

try traveling with a GPS.........but then hills.......

 

I was comparing the speeds on my GPS versus my 99 civic coupe EX and it's OFF!

My civic is stock and while it was reading 80mph on the speedometer, my GPS showed 75mph!!