Tires and gearing
Tire size, gears, crawl and the speedometer, in the order you’d change them.
The steps
- 1
Your truck
What’s on the truck today?
Pick or confirm the truck and the plan to work in. What’s on it now is the baseline the plan is measured from.
- 2
Tire size
Which tire size?
Height sets clearance, gearing, speedometer error and the brakes you need.
Answered byTire size
- 3
Regear
Which axle ratio?
A taller tire is a taller final drive. Past about 5% taller, most trucks want deeper gears to feel stock.
Answered byRegear
- 4
Crawl ratio
Is it slow enough off road?
First gear times low range times the axle ratio sets how slow it can creep.
Answered byCrawl ratio
- 5
Speedometer
What does the speedometer need?
It reads off by the change in tire height until it’s recalibrated, and the odometer and mpg with it.
Answered bySpeedometer
- 6
Review
Review and keep
What changed against Actual, cost and weight where known, and the open checks.
Each step opens its calculator with your truck filled in: Tire size, Regear, Crawl ratio, Speedometer. With JavaScript on, this page keeps your place, your answers and this system’s parts from your build sheet in My garage.
Use at your own risk. These calculators are here to help you plan and to inform your decisions, not to sign off on a build. Many numbers are estimates worked out from factory figures, and some factory figures are not yet confirmed. Check every number against your own truck, its manuals and a qualified shop before you buy parts, cut, weld, lift, regear or drive on it. Long Range Desert Tools is not liable for anything you do based on these calculators or their results. The full terms are in our policies.