The inline-six diesel won’t be available until 2020.

If you’re looking for a 6.2L V8 in your new GM half-ton, the company has you covered as reported yesterday. Those waiting for a diesel, however, will have to wait a bit longer.

According to a report from Automotive News, the company is currently in diesel purgatory thanks to issues with EPA certification. This helps to explain why we learned power output figures but not fuel economy or towing numbers earlier this year.

In a memo sent to dealers earlier this week, The General explained the “slight delay” of a machine that was expected to be on sale roughly about now. Any stores who ordered trucks with the Duramax diesel have had their orders summarily cancelled and will apparently be offered replacement vehicles from the 2020 model year when they’re ready, whenever that may be.

Eggheads at the certification department have been particularly gun shy about diesels since VW tried to game the system with their defeat device. Ram has run into similar problems with certification of their EcoDiesel, forcing them to delay certain product launches as well. None of this means there is anything wrong with the diesel mills, rather that the government is making extra-double certain all hands have their I’s dotted and T’s crossed before allowing the things to be sold.

On the Chevy, the Duramax will be offered on four trims: LT, RST, LTZ, and High Country. This is good news, since many – including your author – feared it would only be an option on high-zoot trims as is the case with GM’s 6.2L V8. Savvy shoppers should note that the cheaper two trims listed here will require customers to pop for one of two Convenience Packages in order to spec the diesel.

Across the showroom, one will find the 3.0L Duramax on a slightly wider range of GMC trucks. In fact, it will be available under the hood of everything except the base model. This includes both the Elevation Double Cab and, interestingly, the off-road focused AT4 with its factory lift and other goodies. As with the Chevy, cheaper GMC trims like the SLE will require the addition of a Convenience Package as well. All this assumes the 2020 models will be optioned in the same fashion as planned for the 2019s. We expect they will.

The 3.0L GM Duramax is expected to make 277 horsepower and 460lb.-ft of torque, heady numbers in the perpetually escalating Detroit truck wars. It’ll be hooked to the company’s ten-speed automatic transmission.