Downloadable instructions for installing Trek Outfitters' custom protection and accessories,as well as, other handy tid bits of info.
All files are .zip Microsoft 2001 Word Files or .txt/simple text Files.
DSII Front Bumper 23 KB 4 KB
DSII Rear Bumper 20 KB 3 KB
DSII Slider 17 KB 2 KB
DSII Front Skid Plate 16 KB 2 KB
DSII Tank Guard 18 KB 2 KB
DSI Front Bumper    
DSI Rear Bumper    
DSI Slider    
DSI Front Skid    
DSI Tank Guard    
Light Protection Bar 13 KB 2 KB
Load Bars    

Axle Ratio/Tire Size Calulator 1.1

Here are a few calculators that may be useful in deciding tire size, gear ratios, and other stuff. These should be compatible with Netscape 3.x and MS Internet Explorer 3.x or above.

Ever wonder how far off your speedometer is with your new bigger tires? I'm using a simple ratio calculation, so this info will only approximate your corrected speed and depends on the accuracy of tire size diameters (assumimg nothing but tire size has changed).

  Speedo converter 
Original Tire Diameter:   
New Tire Diameter:   
Speedometer Reading (MPH):  Corrected Speed (MPH): 

Now that you have your truck lifted, you want bigger meats. They look cool and have the potential of being very functional, but they may also be robbing you of power/gas mileage. This calculator will get you back to a ratio that's closer to your original. Enter the values on the left and press Compute. 

  Find new Gear Ratio with new tire size 
New Tire Diameter:   
Old Tire Diameter:   
Current Gear Ratio:  New Gear Ratio: 

Ever wonder what your low-low-low gear ratio is, your "crawl ratio"? You'll need to do a little research by finding out the transfer case and transmission ratios first. Enter your values on the left side, press Compute and your answer will be on the right. 

  Find Overall Crawl Ratio 
Transmis Ratio:  TransCase Ratio:  Axle Ratio:  Overall Ratio: 

I've spend a bunch of time trying to WAG (wild ass guess) my actual MPH when going down the road. By knowing your gear ratios and tire size you'll get a more accurate idea here. Enter the value on the left, press Compute. 

  Find MPH 
RPM:   Tire Diameter:   
Axle Ratio:  Transmis Ratio:  TransCas Ratio: 

I suppose if you don't have a tachometer you could use this form, otherwise it's only useful to find out how accurate your Tach is. Enter the values on the left, press Compute. 

  Find RPM 
MPH:  Axle Ratio:  Transmis Ratio:  TransCas Ratio:   
Tire Diameter:  

This formula is a nice way to get the tire diameter of those metric tires that are common on just about everything stock. For example a 265/75R16 would be around 31.6 inches tall. Enter the numbers into this form in the order you read them from the tire and press Compute. 

  Convert P-Metric tire to Tire Diameter inches 
Example: 195/75R15 
/   R 
Tire Diameter: 

Copywrite © 1997 by Mark Medina ( These calculators created by Mark Medina