The New Cummins Heavy Duty Diesel Engine and the 100,000 Mile Oil Drain Interval

As every truck or car enthusiast knows, autumn is the time when manufacturers begin to showcase their greatest gear for the coming year. While mainstream media focuses on the elections, there are thousands of other journalists who plan their annual trip to Las Vegas to attend the SEMA Show that they might see first-hand the latest and greatest wares in the auto aftermarket.

Sadly, this year's event -- like so many others -- is going to be virtual. 

This does not prevent carmakers and engine builders from finding ways to flex their muscles a little. Even if only virtual, the World Wide Web is the greatest shopping mall in human history. 

Which brings us to the 2021 Cummins HD X12 and X15. The latest versions of Cummins' emissions-compliant on-highway power plants were introduced at a virtual press event on October 13. The information here is from Truckinginfo.com.

The 2021 engine designs "combine new fuel- and cost-saving features with the proven architecture of the X-series platform." What this means is that customers will experience better fuel efficiency across the entire engine lineup "along with more uptime and greater reliability." 

100,000 Miles!

After taking a deep dive through the features and benefits of the new engines, author Jim Park devoted time to the big reveal: a 100,000 mile oil change interval. 

In the 90's, the CEO of GM stated that it was his desire to see cars produced with a 100,000 mile oil change interval. Consumer studies showed that frequent oil changes were the biggest hassle with regard to owning a car. 

So it's intriguing to see Cummins has stepped up to the plate on this one. Their current oil change interval was already 75,000 miles "for trucks getting 7 mpg or better. (In other words, operating efficiently.) Next year, Cummins has extended the drain interval another 10,000 miles, and supports a 100,000 mile change interval when truck owners used the Cummins OilGuard oil analysis program.

To their credit, Cummins does not specify oil selection as long as it meets standards. Champion is offering special pricing right now for their Blue Flame oils, for what it's worth. (Click on photos in righthand column.) 

The article details a number of hardware changes for the 2021 engines, both electronic and hardware. Air handling has been improved as well as other efficiencies so that the engine runs quieter at idle. 

There's plenty more to write home about. You can read the full story here.

 Photos: courtesy Cummins

Over-Fueling Causes Black Smoke

Modifying a Cummins, Powerstroke or Duramax diesel engine with some sort of OBD-II plug-in or computer-controlled engine management system is one of the simplest ways to improve power for diesel racing and pulling. It’s really not that complicated. You don’t have to take the diesel engine apart, and the modifications cost far less than what’s required to get similar power gains as, for example, from a gasoline-powered motor. 

Because diesels “throttle-push” the amount of fuel injected into the engine rather than limiting the amount of air entering the engine, notable power gains can be achieved by just increasing the amount of fuel delivered. All that’s required is the aforementioned electronics box to alter the signals from the onboard computer that controls the timing and length of the fuel injector pulse and the fuel pressure. There are all sorts of diesel tuner boxes on the market that promise plenty of big power.  

While you can make more power with more fuel, if you don’t do it right, exhaust gas temperatures can go out of sight. This can spell eventual death for the diesel engine or turbocharger. Many diesel racers and pullers are unfortunately unaware of such potential engine damage. They love to increase power and are willing to assume some ownership of the risk, and that’s just what you do when you over-fuel a diesel. 

It is only after getting more airflow into, and out of, a diesel engine that max-power can be achieved safely.  These enhancements include a bigger or less restrictive intake path, inducting cooler air, bigger valves or different camshaft timing, a less restrictive exhaust system, increasing cylinder head flow through porting, turbocharging, or supercharging.

It’s no secret that max-power increases happen when you control both fuel and the airflow. If you don’t burn the extra fuel, then you’re increasing the exhaust gas temperature of a diesel engine  If the exhaust temperature isn’t too excessive, and if it occurs for only for a matter of a few seconds at a time, most diesel engines can withstand the abuse without incurring permanent damage, but there is always that risk.  

The telltale sign of over-fueling and lack of a balanced air flow strategy is excessive thick black smoke coming out of the exhaust pipe.

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Reminder: Be sure to check out the live streaming of this Saturday's Blackout in the Country. To find the feed, click on the button at the top of the right hand column.

Did the Millennium Falcon use OBD-II?

“You’ve never heard of the Millennium Falcon? It’s the ship that made the Kessel Run in less than 12 parsecs,” exclaimed Han Solo, starship pilot. We’re sure they had OBD-II. If dashboard’s ‘check engine’ light came on, Han Solo would have known what to do.

For years vehicle manufacturers have fitted on-board diagnostic (OBD) systems that provide codes to help identify specific issues. You can find the most recent diesel powertrain codes for Duramax, Powerstroke, and Cummins in the right column of this blog. (See the button Diesel Technical Bulletins.)  

But what are these systems and what do these codes mean? Put simply, an OBD system, or on-board diagnostic system, is an on-board computer fitted to your diesel engine that monitors the performance of your truck, including its powertrain, ignition, gearbox and emissions system.

When the truck’s on-board diagnostics system identifies a problem with the vehicle’s performance, it turns on a dashboard warning light and registers a code that identifies the issue.

This engine code, called a Diagnostic Trouble Code (DTC), is stored in the OBD-II system and can only be accessed by connecting a scan, or diagnostic tool into the OBD-II diagnostic socket and reading the DTC off the display of the scanner.

This light is to let you know that a possible fault has developed in the engine management system or another function and may require attention. When you see this appear, check your handbook for instructions on what action to take for your make and model of vehicle.

Diagnostic Trouble Codes, also known as engine fault codes, are five-digit codes that identify a particular problem in the car. These codes are displayed on the scanning tool when it’s connected to the OBD system.

The five-digit DTC includes one letter usually followed by four numbers (e.g. P1234). Each individual combination of letters and numbers relates to a specific problem within the car, whether a generic issue or a manufacturer-specific error.

A DTC won’t tell you which specific part of your car needs fixing or replacing, but it will tell you -- or your mechanic -- what you need to test in order to diagnose the issue. Within the five-digit DTC, one of four letters (P, B, C, U) always comes first and relates to the part of the car that has the issue: P - powertrain, B - body, C - chassis, and U - network.

The second digit (either 0 or 1) relates to whether it’s a general issue (0) or a manufacturer specific problem (1), while the third corresponds to the specific system with the issue, such as the ignition, and can be either a number or letter. The final two digits are numbers that relate to the specific fault description, and there is no pre-approved key to help decode these final two digits. 

“May the Force be with you,” --Obi-Wan Kenobi, the Jedi Master.

Where Do You Turn When You Have Trouble?

I'm not talking about trouble with the law here. I mean, who do you turn to when the Check Engine light comes on or you fry some wires, or your engine keeps shutting off while driving?

In the old days, it helped to have a friend who was a mechanic whom you could call in time of need, assuming you were near a phone. We didn't have cell phones then. (Even better would be a brother.) Today we have something still better. Diesel forums.

Yesterday someone had a dash fire in their Powerstroke and has been dealing with shorted brake light switch wires. Within 16 hours he had five people discussing the situation with him.

Nine hours ago someone named Juniebuck posted some steps they had taken to resolve some issues in their Powerstroke and less than an hour ago there were suggestions of steps that could be taken.

In short, online forums have been a real life saver for all kinds of vehicle owners, especially those in the Diesel World. Instead of relying on your brother, you have a whole family of diesel lovers, many of them directly experienced with your engine type, whether Duramax, Powerstroke or Cummins.

IF YOU LOOK below in the right hand column you'll find links to a full range of diesel forums. If yours isn't listed I would like to add it. Please leave the name and URL in the comments.

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