Duramax Programmer Tuning: Buyer Beware!

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Duramax Programmer Tuning:  Buyer Beware!

Most of us will admit to having just enough knowledge to be dangerous on some subject. For aspiring diesel tuners, the availability of tools like EFILive and HPTuners can make it enticing to tweak a few trucks on the side and make a little money doing it. Fact is, diesel tuning is not quite as straightforward as getting a sample tune off the internet and trying it out. Some of those sample tunes can easily break something. Anyone with a little web savvy can set up a website advertising their tunes and run a business out of their own home and start doing tuning, having just enough knowledge to be dangerous.

To be quite honest, that is the biggest reason I got into tuning in the first place. Having a good understanding of both Diesel and gasoline powertrain management systems, I couldn't stand the idea of not knowing what a power programmer or tuner had changed. I would rather do the job myself, knowing exactly what was going on. As I gained experience, I discovered that most tuners (and aftermarket power programmers) are not quite what they are cracked up to be. I learned that there only a few that I would actually trust.

So how can a customer make an informed decision, especially if the customer is not well educated on tuning?

Tell-Tale #1 - Exaggerated Fuel Economy Claims

You will never see any gains beyond around 10 percent in your fuel economy with just tuning alone. I have had some of my customers come back and brag to me about how they gained 30% in fuel economy after I put one of my tunes in their truck, but they are simply not calculating their fuel economy correctly. Many will fail to account for the original odometer error from running larger tires, which is corrected after tuning. Others will just go off the DIC display for their fuel economy numbers, which is quite variable and usually overly optimistic. In all my testing, and in testing with customers who actually keep proper fuel logs, I have seen best gains of almost exactly 10 percent with my tuning. And let me tell you, I have tried every trick in the book to pull off better fuel economy, and a few that are not in the book either. If you encounter a Duramax programmer claiming 20% or better gains in fuel economy with strictly tuning alone, you may want to look elsewhere.

Tell-Tale #2 - Years of "Automotive" Experience

But do they have years of tuning experience? Do they dig in and repair Duramax engines for a living? Have they seen a representative cross-section of mechanical failures stemming from tuning errors? Do they have the tools for the job, like a combustion chamber pressure monitor? Do they do proper payload or trailer testing? Are they an accredited technician or engineer that actually works out of a shop or do they run a business from their home over the internet? Is it possible to see where they operate out of? Can you drive to their place of business and see them personally? If you get a bad vibe off of any of these questions, you may want to look elsewhere for a Duramax programmer.

Tell-Tale #3 - "This Won't Affect Your Warranty"

Oh, but it does! Making any kind of powertrain modification can potentially affect your powertrain warranty. An in depth examination of this issue is the subject of a Summer 2009 maxxTORQUE article (link requires membership). And don't believe some guy trying to hide behind the Magnuson-Moss Warranty Act, (I explain the typical faulty argument in the article): it simply does not apply to aftermarket modifications. The owner's manual that comes with your truck is very explicit about this. The only hope that you have to avoid warranty denial is to hide the tuning from the technician, which is getting increasingly difficult to do. In fact, with the LMM diesel, it is virtually impossible.

The old rule "if it sounds too good to be true, it probably is" applies with Duramax programmers too. The problem that I personally have with much of the aftermarket performance claims is that they are exaggerated, misrepresented, or oversold. The best tuners are the guys that use their own tuning on a daily basis, get the right education and tools to do the job right, and who get their hands dirty fixing these engines.


If you found this information useful, and are looking for one of the few trustworthy Duramax programmer out there, check out my website www.payntonperformance.com

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