I just got my edge installed and was messing around with the custom stuff the other day and when i try to change the tire size it won't let me and gives me a message saying "This option is not available for this model". I have a 2001 xlt 4x4. Is anyone having this same problem? Does anyone know if i can get and update that will fix this? Thanks for the input in advance.

 

Mine is the same way! Anyone know if they are planning an update for this, I'd like to get my speedo corrected!

 

What version is yours mine allows for the adjustment but the numbers (mm's) don't jive. I have figured out how to get mine dead on but it took abot 10 tries.

 

your truck is a 2003 though. I have a friend who has an 03' and he can adjust his tire size. I have a feeling it has to do with the year model truck not the programmer itself. I should have the newest version firmware because I just got it about a week ago.

 

What size tires do you have? I keep thinking that mine is off....

 

I have 285/75 r16 and I had to set my mm to 2265 to get my speedo right.

 

anybody that could help me figure out what the 305/65/18 would be in the edge? I see the equation but have got no idea how wide my tires are (if thats what its asking) and the chart skips right over 305??

 

Hey man, here is a good tire size calculator thread. Bookmark the link for your tire size calculating pleasure.

http://www.miata.net/garage/tirecalc.html

 

haha, thanks! thats a big help.

 

i have a 99 f150 and didnt have a problem with the tirer adjuster. o yea to help you with the tirer combo, the manual says
285,75r16=2618
285,75r17=2698
285,65r18=2600
285,60r18=2510

 

The manual lies. The correct number for my tires (265/75/16) was 2490. The manual said it should have been 2526 or something like that. Basically, you've gotta do the math and find out what RPM you will be at in a certain gear at a certain MPH. For me, it was 77.97 MPH at 3,000 RPM in 3rd gear (1:1) with 3.55 gears and 31.6" tall tires. Now at 3,000 RPM, my Edge reads 77 mph while my speedo reads 78.

 

It's actually 2525.5 for 265/75/16.

 

Close enough to what the manual says, but with that setting my speedo read 74 at 3,000 RPM in 3rd. I also knew it was off because I would count the mile markers.

 

Brand new tires your size properly inflated would be that measurement. Many variables contribute to tire circumfrence.

 

Setup of this parameter is definetly trial-and-error.

The Edge manual gives a base line number for circumference of a tire that is fully inflated and does not take in the account of the "squish" factor.

It is best to measure your rear tire by marking it with tape or a marker and transfer the mark to the pavement. Have someone observe the mark on the tire as you drive slowly until the tire has made "one" revolution. Now, measure the distance between the two marks that are on the pavement and this will give you your true circumference of your tire as it is on the truck. Metric tape measure works best or multiply by 25.4 to get the milimeter measurement required to load into the Edge programmer. Don't forget to punch in the correct axle ratio your truck has when programming each time.

Example: My 02 Screw has BFGoodrich LT285/70R17 and 3.55 gears. Circumference, when measured, came out to 2520mm. Not even close to what is stated in Edge manual. Programmed the Edge with these numbers and test drove on a highway with mile markers to check. Number was to low as odometer was clocking more than actual driven. Programmed again with higher number 0f 2552 to trick PCM that tires are larger so odometer will clock slower. Now, for every 10 miles driven, odometer clocks an extra .1 tenth of a mile. Programmed again with lower number of 2548 and on recent trip on RT80 showed that my odometer was only off by .1 tenth of a mile after 100 miles driven.

That's as close to as perfect I think I will get unless I want to be really **** and reprogram the Edge with a number of 2547 but cargo weight and other factors will effect this number in the end.

So, as you can see, this "gray" area is by all means....trial-and-error in order to get it right!