Hoosier A40T vs A50T: Which Compound Should You Run for Outlaw & Flat Kart Racing?

Quick answer

• A40T is the softer option (typical durometer listed as 45).
• A50T is the harder option (typical durometer listed as 57).
• Rollout examples from the listings: 33.25" for 10.5x5.0-6 A40T, and 34" for 11.0x9.0-6 A40T/A50T.

What “durometer” really tells you

Durometer is a hardness indicator. It’s not the only variable that matters, but it’s a fast way to understand where a tire sits on the softness/hardness spectrum when you’re deciding between compounds.

• A40T (typical durometer: 45) → generally the “softer feel / more compliance” direction.
• A50T (typical durometer: 57) → generally the “harder / more consistent” direction.

What “rollout” means (and why it matters)

Rollout is how far the tire travels per rotation under real-world conditions. Even before you change sprockets, rollout can affect how the kart “gears” the track and how quickly RPM comes in.

• 10.5x5.0-6 A40T lists rollout: 33.25"
• 11.0x9.0-6 A40T lists rollout: 34"
• 11.0x9.0-6 A50T lists rollout: 34"

When to choose A40T vs A50T

Choose A40T if you want:

• A softer compound direction (typical durometer: 45)
• More compliance/feel and a tire choice aligned to how you want the kart to “talk back”
• Options: A40T 10.5x5.0-6 or A40T 11.0x9.0-6

Choose A50T if you want:

• A harder compound direction (typical durometer: 57)
• A more “consistent” feel depending on your conditions and style
• Option: A50T 11.0x9.0-6

Simple buyer paths (what most racers should do)

• If you’re choosing primarily by compound direction: A40T (45) vs A50T (57)
• If you’re choosing by rollout/size needs:
  • 10.5x5.0-6 A40T → rollout 33.25"
  • 11.0x9.0-6 A40T → rollout 34"
  • 11.0x9.0-6 A50T → rollout 34"

Sizes and prices at a glance

These are the A Series sizes on the Toigo tire pages right now. Prices can change, so confirm on the product page.

• Hoosier 10.5x5.0-6 A40T: 33.25" rollout, $75
• Hoosier 11.0x6.0-6 A40T: 32.5" rollout, $85
• Hoosier 11.0x9.0-6 A40T: 34" rollout, $95
• Hoosier 11.0x9.0-6 A50T: 34" rollout, $95

The product pages describe these tires as built specifically for outlaw kart and flat kart racing, and say the A40T durometer is the same as the D30 tires.

How to think about the choice at your track

Compound is only one piece. Here is a simple way to work through it before you spend money:

• Start with the surface. In general, a softer compound is the more compliant direction and a harder compound is the more consistent direction. Your track prep and how worn in the surface is will change which one you like.
• Change one thing at a time. If you swap compound and size in the same night, you will not know which change did what.
• Write it down. Note the tire, size, air pressure and how the kart felt, then compare at the next race.
• Check your rules. Confirm which tires your class and track allow before you buy.

For tire conditioning and reading the track, read Dirt Kart Tire Prep 101 and browse Gator Grip.

Rollout, gearing and sizes

Because rollout changes how the kart gears the track, a size change can mean a gearing change. If you move between the 32.5", 33.25" and 34" listings, revisit your sprocket and driver combination. The Outlaw Kart Gearing Guide explains how to choose, the Sprockets collection has the parts, and the Hoosier Kart Tire Size & Rollout Guide goes deeper on size.

Running flat kart? Our write-up on the Hoosier A40T for flat kart racing covers why this tire has been popular there.

Wheels, mounting and common mistakes

• Match the tire to the wheel. See the Dirt Kart Wheel Guide for widths and backspacing, and the Beadlock Wheels Buyer Guide if you are weighing beadlocks. Browse Wheels to compare.
• Do not mix rollouts side to side without a plan. Measure and keep matched sets together.
• Do not buy on durometer alone. Size and rollout change how the kart drives too.

Frequently Asked Questions

What durometer is listed for Hoosier A40T and A50T?

The Toigo product pages list a typical durometer of 45 for the A40T and 57 for the A50T. The A40T is the softer compound and the A50T is the harder one.

What rollout do the A40T and A50T tires have?

The 10.5x5.0-6 A40T lists 33.25" of rollout, the 11.0x6.0-6 A40T lists 32.5", and the 11.0x9.0-6 A40T and A50T both list 34".

Is the Hoosier A40T the same as the D30 tire?

The A40T durometer is the same as the D30 tires, per the Toigo product page. Sizes and rollouts differ by tire, so check the listing for the size you want.

Which is better for flat kart and outlaw racing, A40T or A50T?

Neither is better in every case. The A40T is the softer, more compliant choice, and the A50T is the harder, more consistent one, so match the compound to your track conditions and how you want the kart to feel.

Where do I start if I am not sure which tire to buy?

Start with the tires collection, then pick the compound and size you want. If you are still unsure, call the shop and tell us your class, track surface and current setup.