New for 2026: We will have a NTPA Rules Class & PPL Rules Class. The NTPA Class will follow the NTPA Fuel & Water rules and we will be following PPL Rules for  fuel & water standards in the PPL Class. PPL  Diesel fuel standards on the dielectric constant test are greater than 30 and less than 150. Pullers can use their OWN water in 2026. No oxygen carriers or combustion accelerators allowed in water injection. Only  water-soluble oil permitted in water injection. Water injection maximum reading on efractoneter is 5.0  (updated 9/2025)

 

2. Maximum cubic inch limit is 640. Maximum of 8 cylinders permitted.

3. Stock appearing head for that model or series engine permitted. Recast heads permitted

4. Intake manifold: Maximum inlet size 3.75 inch measured on the outside diameter. One inlet pipe only.

5. OEM exhaust manifolds for that model and series engine only permitted on cylinder head.

6. Intercoolers are permitted with the use of water and/or ice only with the tractors weighing 9,200 lbs.

7. Overhead cams are not permitted.

8. Chassis-
8a. Components are not permitted.
8b.OEM rearend, transmission, and engine must be in stock location, bolted and secured to OEM chassis.
8c. Engine can not move independent or rearend/transmission housing(s).
8d. Stock transmission housing or manufacturer’s replacement and stock final drive housings or manufacture’s replacement.
8e. Chassis and frame must remain stock from rear of engine block to the rear of tractor.
8f. Tie bars are mandatory or full frame must be mounted rigid to engine, transmission, and final drive housings.

9. Fuel Systems: Largest fuel injection pump allowed will be P-pump OEM housing with only one plunger per cylinder. No aftermarket pump housings permitted.

10. Turbo Rules for 2020: Limited to ONE 3” by 3” slotted turbo turbocharger

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 11. No waste gates will be permitted.

12. No variable geometric turbos permitted.