Super Dump vs Tri-Axle: Is the Extra Payload Worth It?

A super dump carries more per trip than a tri-axle. On per-ton work that extra payload lets you charge less per ton and still earn the same per hour, or charge the same and earn more. Whether it’s worth it comes down to the extra cost of the truck, your state’s rules, and whether your customers pay for the bigger loads.

To test it with your own numbers, put each truck’s payload into the hourly to per-ton converter with your real round-trip times.

Payload difference

This site uses typical payloads of 24–26 tons for a super dump and 18–25 tons for a tri-axle. The tri-axle range comes from one published source (18–25 tons depending on configuration and state law), and the super dump range from another. The ranges overlap, because configuration and state law matter as much as the truck type.

For the examples below, this site uses its typical default of 21 tons for a tri-axle and 25 tons for a super dump.

Bed volume: this site uses a typical super dump bed of 16–20 yd³ (not yet checked against a published source), and tri-axles typically hold 12–18 cubic yards.

The per-ton math

Take the same hourly rate and the same round trip for both trucks: $110 an hour and a 2.5-hour round trip (10 minutes loading, 65 hauling, 10 dumping, 65 returning). That’s $275 of truck time per load either way. What changes is how many tons that $275 is spread over:

• Tri-axle, 21 tons a load: $13.10/ton
• Super dump, 25 tons a load: $11.00/ton

So at the same per-ton price, the super dump earns more per hour. At a lower per-ton price, it can still earn the same per hour as the tri-axle. That’s the super dump’s advantage on per-ton and per-load work: more tons for the same trip time.

On hourly work the payload doesn’t change what you’re paid per hour, unless customers pay more for a bigger truck. Ask the contractors you haul for.

Running costs

At this site’s example costs (the same truck payment, insurance, permits, driver wage and hours for both, with diesel at $5.35/gal), only fuel use, maintenance and tires differ:

These running costs are this site’s typical estimates, not measured figures. Purchase price and insurance can differ too, so price both with real quotes in the cost per hour calculator.

State rules

Whether a super dump can carry its full payload depends on your state’s weight rules, axle spacing and how the truck is set up and registered. The federal gross vehicle weight limit on Interstate highways is generally 80,000 lb, and bridge formulas and state rules can be stricter.

Check your own state’s rules before you buy. Find your state’s transportation department in FHWA’s list of state transportation departments.

When a super dump pays

A super dump is more likely to pay off when:

• Most of your work is per ton or per load, so extra tons per trip turn straight into extra revenue.
• You haul heavy material (aggregate, asphalt, fill) where the truck reaches its weight limit, not its bed volume. Light material like mulch fills the bed first, and extra payload does nothing.
• Your state’s rules let the truck carry its full payload on the roads you use.
• Customers pay for the extra capacity, either through per-ton pricing or a higher hourly rate.

It’s less likely to pay off when most of your work is hourly at the same rate as a tri-axle, when you haul light material, or when the higher payment and insurance eat the extra revenue.

Run your own comparison

1. Price both trucks with real payments and insurance in the cost per hour calculator.
2. Set your target rate for each in the hourly rate calculator.
3. Put each truck’s legal payload and your real round-trip times into the hourly to per-ton converter, and compare what the same per-ton offer pays per hour.
4. For a specific job, use the bid calculator with each truck’s tons per load.

See also the super dump truck and tri-axle dump truck pages, and the dump truck capacity chart.