I have an Edge (which i will be sending to PHP whenever they get back from a well deserved vacation) and i got some bigger tires. Ive been driving on Level 2, if i change my tire size (295/70/17 = 2574) can i still run on level 2 canned tune or do i have to run a completely custom tune (where i have to input everything manually)?

Basically i want to change my tire size but still run Level 2.

 

Go into pwer programming, level 2. Arrow down toward the end of the choices and there is a selection you can chose that indicates it will save previous settings. Choose that, hit enter. Then go to tires and enter your new size. Old old settings were saved, so you can change only the ones you wish. Otherwise, you will need to enter all of them again.

One other thing, you need to deduct at least 3% for the squish factor, if you didn't.

 

yeah i did, i did a search before i posted and subtracted the 3 percent, thanks for the help

 

What's this 3% squish factor, I haven't heard of that.....I can't see that being too crucial?

 

It is the amount your tire flattens out. I had to deduct 5% to get mine accurate. Just depends how important 2 or 3 mph is to you. I want mine accurate.

 

i thought the Edge would correct the Factory speedo, cause my GPS says 65, Edge says 66, and my truck says 69.

When i input my tire size heres what i did, tell me if it saved my level 2,

Power Settings
Level 2
Would you like to custom tune, YES
changed my gear ratio to 355 and my tire size
then i hit done.

 

You need to increase your tire size slightly. (unless I'm going backwards ). Change it by about 10 points and see what happens. I always want the Edge to agree with the GPS. The truck speedo will always be 2 to 3 mph faster than the Edge. Ford does that so you will use up the warranty quicker.

 

well my gryphon/edge kept defaulting to one size bigger than my actual size that I programmed in (2563vs.2559). Note: both of these sizes were much larger than the original default size in the canned tuning (it was 2335 or something). Anyway, the larger size (2563) is bang on with my GPS and truck speedo....and truck rpm's!
Now I input 2554 or something and it rounds up and saves my 2559. It seems to want to round up slightly for some reason....even when I save my settings. No matter 2559 and 2563 are so frikken close it don't matter. 4mm is pretty miniscule. I certainly do not need to deduct another 3-5% to get it accurate though???

 

Direct exerpt from manual:

Circumference Equation:
[(width * ratio * 0.02) + (rim * 25.4)] * 3.1415

Steps:
1. Multiply Width, Ratio and 0.02
2. Multiply Rim and 25.4
3. Add Step #1 with Step #2
4. Multiply Step #3 with 3.1416
5. The result will be the circumference of your tire in mm.

My edge and speedo pretty dead on w/o the squish factor, using these calculations

 

yup......zero squish factor required for me either.
If there were a squish factor truely required you would think that the calculation would also be a step in that equation!

 

Bill uses an equation that includes it. Since it can vary from 3% to 5%, it is often left to the user. I had to use 3% on my previous tires and 5% on my current tires, to get agreement with a GPS.