lscfa wrote: PIT has not created a true base case to fairly compare the results from a truck with a hydrogen injection device onboard. Results will overstate the fuel savings from a hydrogen injection device.
A fair base case would involve measuring the “average” fuel consumption of a truck over a period of operation that spans several scheduled maintenance/cleaning sessions. This is because the fuel consumption is lowest after servicing and gradually increases as carbon builds up in the engine.
Measuring the fuel consumption of a truck with no H2 device over a short period of time does not represent its true consumption so it is not valid to compare it to a truck with a H2 device.
Imagine doing the PIT testing in reverse fashion. Start with 2 trucks that have been carbon cleaned. Measure the mpg of both to confirm they are the same. Then add a H2 device to one and immediately measure the mpg again for both. It will likely show a small improvement (5%) for the H2 device. Now operate both trucks the same for 1 month, 2 months, 3 months, etc. What will be observed is that the mpg for the truck with the H2 device does not change but the truck with no H2 device will have declining mpg each and every month (10%) until it is cleaned again. This is where the total 15% fuel savings comparison come from in the case of field trials like Pepsi.
One culprit being assigned blame are direct injection systems. As vehicles have moved toward direct injection, mechanics are seeing more carbon build-up in the engine. The carbon builds up around intake valves and erodes whatever performance or mileage gains the engine gets from having direct injection in the first place. How much of a loss? Studies have been done on diesel cars taking newer vehicles (starting at 15,000 miles) and comparing the horsepower of the vehicle at that point and then with another 5,000 miles added (along with the intake valve carbon deposits). At 15,000 miles, the cars had 324 "all-wheel horsepower". 5,000 miles later, the horsepower was measured at 317. Another 5,000 miles and the horsepower was all the way down to just 305. That's a drop of almost ten percent in less 10,000 miles.
The best thing you can do to keep your diesel engine clean and free of deposits is to use a fuel treatment with detergency. Diesel fuel has no requirement to come with detergency, unlike gasoline. You can use a "keep-clean" detergent, but you'll also get excellent results if you choose an every day treatment with each fill-up.
https://www.bellperformance.com/bell-performs-blog/blog/carbon-buildup-in-diesel-engines