What is Diameter of LT215/75-17.5 Trailer Tire Size

Updated 03/01/2026 | Published 11/06/2023

Question:

OK. This is for a trailer to be built late this year. Its to be a cargo trailer customized into a travel trailer, 28 ft. L x 8 1/2 W x 9 1/2H. Two 8,000 lb. torsion axles. So far Im looking at LT 215/75R 17.5 tires. My question involves clearance from the bottom of the trailer to the road surface. In the trailer floor Ill have recessed water tanks 16inch deep. Due to insulation the floors will be 6inch thick. This leaves me 10 inches of tank to clear the road. So, first, will I have enough clearance with these tires for the bottom of the water tank to clear the road? Id like to have as much clearance as possible. If this size tire gives me just a little clearance, would this product work for me with two 8,000 torsion axles? I see each lift kit is rated for 3,500 lbs. Thanks!

asked by: Jim P

Expert Reply:

I don't have quite enough info to determine if you have enough clearance but I don't know where your axle will be located relative to the dimensions you listed. The tire size 215//75R17.5 like part # LHAS701 has a diameter of 30.2 inches which means from center of the axle it will extend down to ground 15.1 inches which could help you determine what type of ground clearance you'd need with your axle location.

expert reply by: Jameson C

Bennie

3/1/2026

This is not correct. The distance from the axle to the ground is NOT half of the tire diameter. That distance is called the Static Loaded Radius (SLR). This accounts for how much the tire squats down and flattens out at the bottom. For a 215/75R 17.5 tire, the SLR is between 14.0" and 14.4" depending on the brand.

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