Gear/ tire change charts

I know there is a ton of information on here about different tires sizes and gear ratios. In figuring out my ideal ratio, I created a chart in excel, and expanded it to include all tires sizes, diff ratios, and both transmission, along with some helpful information that I found. I used formulas to create it so I have not verified every bit of info, but I think it is fairly accurate. If you take a look, please verify my numbers with your real world experiences.
Also, not all of the numbers shown are physically possible. I dont think anyone has a 4.0 capable of 12k RPM, or 200MPH+

Alright, well for some reason It says I cant post an attachment. Im thinking its maybe because im not a member? This spreadsheet would be helpful to a lot of people, is there any way around this?

Where's the file?

It's pretty simple...for 31-33" tires, my driving preferences are as follows...

31s - 4.10
32s - 4.56
33s - 4.88

That gives you an optimal amount of low-end torque that is a great combo for dd'ing, off-roading, and activities such as towing a trailer or driving in the mountains. That's what I recommend to people. Those who would argue against it, for the under-gear argument, are only doing so to justify their own decision, which there is a 3-page thread about that going on right now. More power to those who over-gear (lower numerically). But I'll let the can of worms open up now...

No need to open that can of worms, there are like 100 posts that do it already, im just trying to post a full set of calculations for every gear ratio, and most tires sizes. I just cant figure it out.. if anyone knows what im doing wrong.

There are dozens of charts like that out there already.

Also, you can't post attachments in the tech forums.

Well if you just want the formula help...here you go...

3.55 (stock gear on auto 4.0) DIVIDED by 28.3 (stock tire size in inches) EQUALS 0.125

To get the new required gear ratio to maintain the 0.125 figure, you have:
X (the new gear ration you're solving for) EQUALS 0.125 MULTIPLIED by Y (new tire size in inches)

So if you want 31s (most are 30.8") you multiply 0.125 by 30.8 and get 3.85. You're in between two gear ratios there, 3.73 and 4.10...I'd go 4.10. You have to remember the larger tires weigh more so you can't calculate for that using this equation...you could but it's just easier to pick the larger (numerically) one.

Make sense?

cal said:

There are dozens of charts like that out there already.

Also, you can't post attachments in the tech forums.

Click to expand...

Oh yeah, and like Cal said...there's dozens of them out there already. IMO they all just over complicate the subject.

I know there are charts out there, but they are spread out, and dont cover everyones setup. The one I made consolidates the information and covers stroker/4.0, aw4/ax-15(each gear, and 21 vs 23 spline), 7 gear ratios, 9 tires sizes, and shows rpm vs mph. In my opinion, its worth some complication to figure out exactly what you want before spending hundreds of dollars and countless hours regearing. If no one is interested that is fine, but if you are the link is here: http://lightfootxj.webs.com/index.htm

Holy crap. Exactly like I said...over complication. But kudos for the effort :cheers:.