Pro UTV Parts

12/03/2025

Gear/Tire Changes vs Speed Calculations Made Simple

True GPS speed decreases proportional to the % reduction in gearing. This applies to transmission and portal gear lift/reductions. GPS true speed also increases proportional to tire size increase. Speed decreases with tire size reductions.

In the example below we will not talk about reverse because it closely mirrors low range reduction.

Example:

Polaris Turbo with 30" tires moves up to 35" tires. (1- (30/25)) x 100 = 14.29% tire size increase.

Same Polaris Turbo lowers transmission gearing by 21% in low range and 32% in high range. High and low gear changes are additive to low range Polaris turbo transmissions. High range gear swaps apply to high range only and high is unaffected by low range gear changes.

Total Low Range Reduction = 21% + 32% = 53%

Top Speed Stock 30" tires (TSS) = 80 mph

Total Low Range Reduction (TLRR) = 53%
Low Range Reduction (LRG) = 21%
High Range Reduction (HRG) = 32%
Tire Size Increase (TSI) = 14.29%
New Top Speed (NTS)

(1- (HRG - TSI/100)) x TSS = NTS
(1 - (32%-14.29%/100)) x 80 mph = NTS = 65.83mph



Note: If you want your speedometer to read correctly see below.

https://www.proutvparts.com/products/polaris-speeddoctor-speedometer-correction-kit?_pos=1&_sid=912457ff3&_ss=r

https://www.proutvparts.com/products/super-atv-honda-speeddoctor-speedometer-correction-kit?_pos=2&_sid=912457ff3&_ss=r

https://www.proutvparts.com/products/super-atv-can-am-speeddoctor-speedometer-correction-kit?_pos=3&_sid=912457ff3&_ss=r

11/05/2025

30" Paddle Tire Blowout Sale ($389.99/set). 14" Sand King Paddles. Send us a message if you want them.

11/02/2025

Pro UTV Parts has Several Halo 30s in stock at 10% off. Purchase now while this great deal is running.

SKU: H-HALO-30 33 Spline Halo 30 Diff for CanAm This is the best of the best, the Halo 30 locker setup is the strongest locker available anywhere for the Can-Am. Included is a billet case, 6 gear chromoly carrier, Halo locker kit, new seals and bearings, larger and stronger custom spider gears. The....

10/29/2025

Trail Hero 2025 Sand Hollow. Maxxis SXS Shootout. Big shout out to Trail Hero and Maxxis for the great time!

https://www.facebook.com/reel/2691096121243446

08/08/2025

RIP Walker Evans

01/24/2025

COOL-it Custom Overhead Fans. Get them here. https://www.proutvparts.com/products/cool-it-custom-overhead-fans

09/20/2024

Tnt hood scoops are super cool looking and cool the inside of thr Pro R, Turbo R, and Pro S. They have a diffuser that evenly cools the firewall. There is also water separator for the clutch intake.

https://www.proutvparts.com/products/tnt-pro-r-cold-air-hood-scoop?_pos=1&_sid=13d9b15d6&_ss=r&variant=45593544851681 #

TNT Hood Scoop Fitment: Pro R Turbo R Pro XP Hood Scoop Only (no diffuser yet, coming soon) The TNT Hood scoop looks cool and keeps the cab cooler! Hood Scoop color is black with or without TNT Logo. To cool the cab a hood scoop and air diffuser are needed. The Frog Screen water filter helps block w...

09/10/2024

Farmington 4X4 week 2024. Went to Farmington with all the old guys and rode trails for the week. Picked up 1st place at the ramp competition in town with the Cliff Hangers 4x4 club in downtown Farming Friday night (see photo). Also connected with an old friend and famous ARCA course designer Phil Collard at the event. Phil handed over his last ARCA hat and the tape measure used to construct all the ARCA courses 23 years ago (see photo). This was an emotional moment. Also picked up 2nd place at the Werock event with Werock National Champ Jesse Haynes spotting. Thanks Jesse!

11/17/2023

Black Friday 35"-37" Roxxzillas Cheap!!! Call, text or email fast before they are gone!!!!

03/07/2023