This article originally published in Issue 61 of the Turbo Diesel Register.

Technical Topics

IT'S ABOUT THE (fuel) ECONOMY STUPID!

No, I’m not running for office this election year. But, with my knack for the obvious, I know the focus of attention is fuel economy. So much so that I could be accused of head-in-the-sand mentality were I not to acknowledge that I’ve heard many conversations about parking the truck and purchasing a beat-up economy car.

I’ve thought the same. Before you make a like decision, be sure to factor all of the cost. You’ll likely find that the beater car’s payback is longer than you first realize.

Nonetheless, I wanted a quick solution to the fuel economy crisis. So, I went to Wal-Mart.

No magic fuel magnets were found on the shelf. Out of stock.

The air tornado thing was not large enough for my truck’s intake. The fevered pace with which I started this article was now in neutral. If the fuel magnet or the tornado salesman had come calling I would have purchased the products out of sheer frustration. Maybe I should do some further research.

As I look back, it was 10 issues ago (Issue 51) or the winter season of 2005/2006 that we had the TDR writers tell us about their strategies for driving their diesel in a $3 gallon world. This was just after hurricane Katrina, but prior to ULSD fuel and the higher world wide demand for diesel. Diesel fuel was still lower or equal to the price of regular grade unleaded gasoline. Diesel owners were still pleased with their choice of engine and we enjoyed the benefit of the engine’s 35% better fuel economy than the gasoline counterpart. Today’s price premium for diesel fuel (about 20% here in Georgia) really hurts.

So, I went back to Issue 51 to see how easy it might be to write a sequel article. I was captivated by the writer’s stories.

Issue 51, like a conversation with an old friend, is worth your reread.

• Doug Leno’s cost/benefit analysis on fuel economy gadgets.

• Brad Nelson’s pinecone and boost build-up driving technique.

• Bruce Armstrong’s EGT at 600° driving technique.

• Greg Whale’s analysis of price versus Europe where fuel was $6 for diesel and $8 for gasoline.

• Scott Dalgleish’s fuel economy project truck and the connection of the wallet to the right foot.

• John Holmes’ price of fuel versus minimum wage comparison.

• Jerry Neilsen’s pledge to slow down and use the cruise control. Jerry also noted that “everything is a matter of perspective.”

• Joe Donnelly points out the obvious and refers the readers back to Issue 47.

• Mixed in with the fuel economy comments you can’t miss the late Ron Khol’s tell-it-like-it-is political commentary.

Throughout Issue 51 several writers made reference to Joe Donnelly’s “Fuel Economy with Power” article in Issue 47. So I picked it up and searched for information. Rather than reinvent the wheel (actually Issue 47’s article was an update from Joe’s Issue 29 material), I’ll review with you some of the Issue 47 text. The first thing that caught my attention was the cliché often seen in the TDR, “The more things change the more they remain the same.” As this bit of reality set in, it slowed my fevered pace to find the key that would unlock a dramatic fuel economy breakthrough.

Regarding fuel mileage (and for that matter performance and exhaust emissions), this bit of reality was presented in Issue 47. “Editor’s note: you may say to yourself, ‘Gee, it looks all too simple…change (advance) the timing of the fuel delivery (on the 12-valve engines this is a mechanical change; on the 24-valve engines and HPCR engines many of the auxiliary black-boxes do the timing change) and throw in a set of big injectors for better mileage and power. Pretty simple, eh? Why didn’t those guys at the factory do that?’ The answer is as simple as two words: exhaust emissions! Dodge and Cummins have to play by a different set of rules than the owner of the vehicle. It is true that tampering with or disabling any component of the emissions control system (timing changes and big injectors are included here) is a direct violation of federal law (fines up to $25,000 per day, per violation). Owners have to weigh the consequences versus the increase in performance, and in this example, fuel mileage (Issue 60, page 50).”

Automotive Performance Curve (Click on chart for larger image.)

Engine Performance Curve (Click on chart for larger image.)