Load index and speed rating requirements for US trucks
Every truck has a tyre placard showing the minimum load index and speed rating. Fitting tyres below those figures is unroadworthy and can void insurance. On RAM 2500/3500, Silverado HD and F-250/F-350 trucks, that usually means LT (light truck) tyres with a load range E — often called 10-ply rated.
| Tyre type | Typical use | Notes |
|---|---|---|
| P-metric / standard load | Some 1500-series trucks from factory | Lower load capacity; not ideal for heavy towing |
| LT load range C / D | 1500-series towing and touring | Stiffer sidewall, higher load capacity |
| LT load range E (10-ply rated) | 2500 / 3500 HD trucks and heavy towing | Highest common rating; run at correct pressures for load |
Check the load index on the tyre sidewall against your placard — not just the size. Two tyres the same size can carry very different loads. For a deeper dive, see our tyre load rating guide.
All-terrain vs rugged-terrain tyres for towing and touring
| All-terrain (A/T) | Rugged-terrain (R/T) | |
|---|---|---|
| Road noise | Quieter | Louder |
| Wet-road grip | Generally better | Good, varies by brand |
| Off-road / beach | Capable for most touring | Stronger in mud, rock and sand |
| Sidewall strength | Good | Usually tougher |
| Best for | Caravans, highway towing, daily use | Heavy off-road touring with occasional towing |
For most Sunshine Coast owners towing a caravan up the Bruce Highway or heading to Fraser, a quality LT all-terrain in the correct load range is the right call. R/T tyres make sense if you spend real time off-road and accept extra noise and cost.
Why standard tyre shops struggle with US pickup alignments
Full-size American trucks are long, heavy and often lifted or levelled. A basic toe-only alignment can leave caster and camber wrong, causing wandering, pulling and uneven tyre wear. Lift and level kits change front-end geometry, and many trucks need adjustable components or offset parts to bring caster back into spec.
- Caster correction after lifts and levelling kits — key for straight-line stability when towing.
- Camber checks, especially on IFS trucks with torsion bar or strut adjustments.
- Steering wheel centring after any suspension work.
- Checks for worn ball joints, tie rod ends and track bar bushes before aligning.
- Alignment set to suit the truck's typical ride height and load.
Our precision truck wheel alignment uses equipment and specs suited to full-size US pickups, so the truck tracks straight laden or unladen. We look after RAM, Ford and GMC and Chevrolet servicing in the same workshop, so suspension, steering and tyres are all checked together.
Tyre rotation schedules to prevent cupping and edge wear
- 1Rotate every 8,000–10,000 km, or at every service.
- 2Use the rotation pattern recommended for your tyres (directional tyres differ).
- 3Adjust pressures to load — run higher when towing, per the tyre maker's load tables.
- 4Check for cupping or outer-edge wear, which points to worn shocks or alignment issues.
- 5Include the full-size spare in the rotation if it matches.
- 6Re-check alignment after hitting a big pothole, kerb or after suspension work.
Need new rubber or a proper alignment? Enquire about truck tyres & fitting at our Caloundra workshop.
Frequently asked questions
- What tyres should I put on a RAM 2500?
- Most RAM 2500 owners run LT load range E (10-ply rated) tyres that meet or exceed the placard load index. An all-terrain pattern suits most towing and touring use.
- Do lifted American trucks need a special wheel alignment?
- Yes. Lift and level kits change caster and camber. A proper alignment checks and corrects all angles, often using adjustable parts, not just toe.
- How often should I rotate tyres on a Silverado?
- Every 8,000–10,000 km, or at each service, helps prevent uneven wear and cupping on heavy trucks.
- Are A/T or R/T tyres better for towing a caravan?
- For most caravan towing, a quality LT all-terrain tyre in the correct load range is quieter and grips well on wet roads. R/T suits owners doing heavier off-road touring.
- Do you do wheel alignments for RAM 1500s in Caloundra?
- Yes. We align RAM 1500s and other full-size US pickups at our Caloundra workshop, including lifted and levelled trucks.
About the author
Lachlan Matthews — Owner
Lachlan owns American Truck Centre in Caloundra and has spent more than 10 years working on American trucks and full-size US pickups. He oversees every job that comes through the workshop, from logbook servicing and diagnostics to suspension, towing setups and transmission work.
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