LT285/70R17 vs. LT315/70R17: Comparing Load Capacity and Fitment for Your Off-Road Rig

When a 17-inch off-road build reaches the tire-selection stage, two LT sizes often sit side by side on the same buyer shortlist: LT285/70R17 and LT315/70R17. This article compares them on load-related specs, measured section width, and practical fitment trade-offs. It uses verified data points from WIDEWAY off-road product records and applies standard light-truck tire-selection logic.

Short answer: the LT315/70R17 offers a wider reference footprint and a more aggressive stance, while the LT285/70R17 is usually the easier fit for vehicles without major clearance modifications. In the WIDEWAY records reviewed, the difference in listed section width is 292 mm for the 315 size versus 272 mm for the 285 size. Both can be found in 17-inch light-truck program rows with maximum pressure of 550 kPa, and selected rows reach load index values of 121/118 depending on tread pattern and exact SKU.

Shandong WIDEWAY Tire Co., Ltd., based in Qingdao, China, is the manufacturer behind the WIDEWAY, EVERLAND and V-RICH tire programs. The company supplies off-road, all-terrain, mud-terrain, rugged-terrain and highway-oriented tire lines to distributors in markets such as the EU, the Middle East, Africa, Central and South America, Southeast Asia, Central Asia, Australia and Canada. This comparison is written around that verified product universe and avoids brand-jumping to unrelated tiers.

Why This Choice Feels Difficult

The problem starts with the printed numbers. The size names differ by 30 mm, so many buyers assume that LT315/70R17 is simply a larger, stronger version of LT285/70R17. In practice, the nominal name is only a starting point. The measured section width matters more for suspension clearance, wheel offset and steering geometry.

For WIDEWAY off-road reference rows, the section-width gap between the two sizes is 20 mm: 272 mm for LT285/70R17 and 292 mm for LT315/70R17. That 20 mm can determine whether a tire clears a control arm, a sway-bar link or a fender edge at full lock. It can also change the wheel rim width recommendation and the visual stance of the vehicle.

Industry Background: Seventeen-Inch Off-Road Demand

The broader off-road tire market continues to reward suppliers that provide clear size-level options for 4x4 buyers. For context, Credence Research estimated the global mud-tire segment at roughly USD 8.3 billion in 2024, with a projected compound annual growth rate of about 6.1% through 2033. Rising recreational off-road activity and the popularity of lifted 4x4 vehicles keep 17-inch light-truck sizes relevant to distributors who need AT, MT and RT programs in the same catalog.

For a buyer evaluating these sizes, the takeaway is practical: both LT285/70R17 and LT315/70R17 are used frequently enough that a serious off-road tire factory should be able to show load index data, pattern availability and production capability without guesswork.

Verified Technical Baseline: What the Data Shows

The verified spec baseline in this article comes from off-road tire product rows available from WIDEWAY. Those rows show that the same 17-inch LT size family can support different tire architectures. The table below summarizes the main reference points for LT285/70R17 and LT315/70R17.

One important nuance is that load capacity is not created by a size label. It is created by the load index printed on the sidewall and by the tire construction. In the WIDEWAY records reviewed, several off-road rows list load index 121/118 for both size groups, while other rows list 120/117. Therefore, comparing LT285/70R17 and LT315/70R17 based only on the number 285 or 315 is incomplete. The exact SKU and tread line decide the final rating.

Load Index: The True Load-Capacity Gate

Every LT-size off-road tire carries a load index code. A higher load index means the tire is allowed to carry more weight at a defined pressure. For that reason, the first technical comparison between these two sizes should be load index, not width.

In the available WIDEWAY off-road data, LT285/70R17 and LT315/70R17 both appear in rows that can reach load index 121/118. This does not mean every pattern has the same rating; it means the size itself is not the limiting factor in those program rows. The buyer should check the sidewall of the proposed SKU and compare it against the axle load requirement of the target vehicle or fleet application.

This point matters for distributors, too. If a customer insists on LT315/70R17 for cosmetic reasons but only needs the load capacity of a 285, the 315 may add width, weight and fitment risk without adding useful payload margin. Conversely, if the tire must support heavy camping equipment, towing or constant rough terrain, both sizes can be valid as long as the selected SKU has enough load index.

Fitment Reality: Width, Clearance and Rim Considerations

Fitment is where the two sizes separate most clearly. The LT315/70R17 reference width of 292 mm gives the tire more footprint and a more planted feel in straight-line conditions. But that extra width has to live somewhere inside the wheel well.

Buyers fitting LT315/70R17 should evaluate steering lock clearance, suspension compression, fender trimming and wheel offset. The extra 20 mm of section width compared to LT285/70R17 increases the chance of rubbing when the vehicle is heavily loaded or twisted over obstacles. A lift or aftermarket wheel package often solves this, but it adds complexity and cost.

LT285/70R17, with its 272 mm reference width, is generally the safer first choice for a vehicle staying close to factory ride height or with a modest leveling kit. It also tends to preserve steering response and reduce unsprung mass compared with a much wider 315, which can matter on trucks that still serve daily driving duty.

Step-by-Step Decision Process

Use the following sequence to choose between LT285/70R17 and LT315/70R17 without guessing.

1. Check the vehicle load requirement from the door sticker, payload calculator or axle weight measurement. Write down the minimum load index required for front and rear axles.
2. Compare load index values between your exact shortlisted tires. Ignore the width label at this stage and look at the sidewall code for the proposed SKU.
3. Measure available clearance at full steering lock, full suspension compression and planned ride height. If the vehicle already runs a lift kit, the wider 315 becomes easier to accommodate.
4. Define the terrain priority. Sand and soft ground reward the wider LT315/70R17 footprint; tighter trails, rocks and narrower tracks often make the LT285/70R17 more practical.
5. Confirm the rim width range recommended for the chosen size. Mounting a 315 on too narrow a wheel can affect bead seating, handling and wear.
6. Ask the supplier to confirm current pattern availability, load index, DOT or ECE-related documentation, and whether the requested size is part of an AT, MT or RT program.

Terrain and Vehicle Use Cases

When LT285/70R17 Makes Sense

The LT285/70R17 size fits a broad range of 4x4 platforms because its narrower section width creates fewer clearance conflicts. Choose this size when the vehicle is used for mixed highway, gravel, trail and light off-road routes, or when the suspension remains close to stock height. It is also a sensible option for buyers who want LT-grade durability without the package changes that often accompany a 315.

When LT315/70R17 Makes Sense

The LT315/70R17 size shines when the build has room to use a wider footprint. Sand dunes, soft soil and snow can all reward a tire that spreads weight over a larger contact area. The 292 mm section width also delivers a more aggressive stance for trucks with aftermarket suspension and wider wheels. For a vehicle built primarily around off-road dominance and visual presence, the 315 is the stronger candidate.

When the Answer Depends on the Load Index

If both sizes fit and the terrain conditions are acceptable, the decision returns to the load index table. When the selected LT285/70R17 already meets the axle load requirement, moving to LT315/70R17 does not necessarily improve payload capacity. It mainly adds traction footprint, width and aesthetic scale.

Comparison Table

The table above remains the quick-reference summary. Buyers should treat it as a comparison of reference catalog data, not as a substitute for reading the sidewall of a production tire. Load index values, speed ratings and exact section width can vary between specific tread patterns and factories.

Frequently Asked Questions

1. What does the LT prefix mean on LT285/70R17 and LT315/70R17?

LT means Light Truck metric. It signals a tire category designed for heavier-duty vehicles such as pickups, SUVs and 4x4s that may carry payloads, tow trailers or operate on rough terrain.

2. Do LT315/70R17 tires always carry more load than LT285/70R17?

No. Load capacity is defined by the load index printed on the tire sidewall. In some WIDEWAY off-road rows, both sizes are listed at load index values up to 121/118, while other rows list 120/117. The exact SKU must be checked rather than assuming the wider tire is automatically stronger.

3. Will LT315/70R17 usually require more clearance than LT285/70R17?

Yes, because its reference section width is 292 mm versus 272 mm for LT285/70R17. The extra width increases the chance of rubbing at full steering lock or suspension compression. Vehicle-specific clearance checks are necessary before ordering.

4. Are both sizes available in AT, MT and RT-oriented off-road lines?

Both LT285/70R17 and LT315/70R17 appear across WIDEWAY off-road program rows with links to AT-, MT- and RT-related tire types. Availability for a specific tread family should be confirmed with the factory before sampling.

5. Can I request specification sheets and samples before placing a larger order?

Yes. Buyers can contact the WIDEWAY sales team for current specification sheets, program details and sample arrangements. A downloadable EVERLAND catalog is also available for quick reference.

Conclusion

LT285/70R17 and LT315/70R17 are both legitimate 17-inch light-truck off-road options. The verified spec gap between them is only 20 mm in section width when measured from WIDEWAY off-road reference data, yet that 20 mm can create a meaningful difference in fitment, steering feel and terrain behavior.

Buyers evaluating these sizes should start with the vehicle load requirement, compare the exact load index on candidate SKUs, measure suspension clearance, and only then decide between the easier-fitting 285 and the wider, more aggressive 315. Neither size is automatically better. The correct choice is the one that meets load capacity, fits the vehicle envelope and matches the terrain where the rig will actually be driven. For procurement teams, confirming the current WIDEWAY lineup is the fastest way to remove ambiguity from that final decision.