My speedo is off by 5 mph need help?

You can go to Ford give them your vin# and tire size and a mechanic should be able to figure out what pick up,sensor or gear you need to make it accuracte. The easy and quick way is to buy a GPS unit and it reads your true speed.That is how we use to check speedo calibration. Mount the GPS and use it for the speedo. Most Fords are about 3 MPH off from the factory anyway.

Most certainly does
You need a different gear in the trans or transfer case,that drives the speedo
Now if the speed sensor is the output,then you will need help. I personally do not know, if a scan tool can reprogram the ecm/bcm etc, to correct for the tire change.

Ask that question next.

do you have aftermarket wheel on the car?? bigger wheels can cause speed signal failure resulting in speedo acting up. different size tires will have different circumference causing speedo issues.

I believe it will fit. If you go to DiscountTires.com you can use their site for alternate tire sizes. Especially handy is the feature which shows you the Speedometer error for different size tires. The site will also show you recommended and popular substitute tire and wheel sizes.

The 1999 model had a 265/65/17 as an alternative. You may want to ask the Tire store you intend to use if they can reconfigure your Speedo to be accurate. Some of the Fords can be done electrically without changing Speedo gears.

I did something similar by going from a "60" series to a "65" series in the same width. On my Grand Marquis, I gained 5% mileage improvement, but have to watch Speedo until I get it reconfigured. I hope this helps to answer your questions.

i have 1 up size tires on my pick-up and the difference on the speedo is aproximately 2 mph slower than actual.

to be straight forward! the size of the rim/tire will not affect speedo tran ect ! the speedo is on the trans ! the truk will register correctly! speed that is

There is no one stock speedo gear in a Chev. It is dependant on the combination of rear end ratio, transmission and tire size. Each car has the potential to be different. Theyare easily interchangeable. There is a small bolt holding a clamp where the speedo cable goes into the trans. Unbolt it and the speedo gear pops right out and slides off the end of the cable. If your speedometer is too slow put a bigger gear on, too fast needs a smaller one. It's trial and error but I think each tooth difference is 5 MPH, it's been awhile. Hope this helps.

205 75 14. There should be a sticker on your door jam.

someone has modified. the speedometer cable has to be taken loose from the tranny and put back in. the only way it can be that wrong.

CHECK IF YOU HAVE THE correct size tire
open driver door locate tire tag and compare the size with what u have