7.00-15LT vs P235/75R15 XL

[CapriRacer]

Top asked me to join in on conversations about 7.00-15LT’s – particularly with regard to replacing those with P235/75R15 XL’s. The threads he pointed me to were cluttered with other topics – so I decided to start a new one.
7.00-15LT
Diameter: 29.6”
Width: 8.0” (on a 5.5” rim)
Load Carrying Capacity : Load Range C: 1710# @ 45 psi (bias) / 50 psi (radial) – Single (I am not going to quote duals)
Load Range D: 2040# @ 60/65
Load Range E: 2335# @ 75/80
Speed restriction: 65 mph

P235/75R15 XL
Diameter: 28.9”
Width: 8.8” on a 6” rim (8.6” on a 5.5”)
Load carrying capacity: 2183# @ 41 psi (1985# @ 41 psi when used on a trailer)
Speed Restriction: Varies by tire


My first reaction is that it is smaller in diameter, wider (a concern!), and for Load Range C - on paper - there is enough load carrying capacity. For Load Range D – on paper – there is a difference of 55# (the wrong way) - and here is where it gets complex.

Because of the difference in speed restriction, this weight difference is not a concern - FOR ME!!. It may be a concern for others – and that is understandable.

Taking this a next step – Load Range E: On paper, there is a 350# difference – and I think this is just beyond the limit (adjusting for speed)


Let’s look at an ST tire:

ST205/75R15:
27.1”
8.0 on a 5.5” rim
Load Carrying Capacity: Load Range B: 1480# @ 35 psi
Load Range C: 1820# @ 50 psi
Load Range D: 2150# @ 65 psi
Aside from the load carrying capacity and the reduction in diameter, this appears to be a viable option.

How about ST225/75R15?
28.3”
8.8” on a 6” rim (8.6” on a 5.5” rim)
LR B: 1760# @ 35 psi
LR C: 2150# @ 50 psi
LR D: 2540# @ 65 psi
Aside from the width, this looks viable.


I want to take a moment to talk about clearances:
First, I am not a fan of tires contacting body parts, frames, and suspension members. Bad things have been known to happen.
Diameter: That’s pretty easy to deal with. The static clearance can easily be measured and there is an obvious limit before the suspension bottoms out.
Width; The static clearance can be measured, but under cornering, the issue becomes less clear. I am VERY nervous about width clearances, so I tend to emphasize staying close to the original dimension.
And those are my thoughts.

[Lance M]

Thanks very much for your thoughts and numbers.
So as long as there are no clearance issues, you would recommend these P235/75/15XL to replace original equipment 7.00x15LT bias ply load range C or D?