flat4_5spd said:
Curtis, I see your point that not all diesel tuning is created equal, and it's probably safe to assume that a mpg or power tune won't be as environmentally destructive as a coal rolling tune, but you're providing data about fuel economy, horsepower and torque but nothing about the emissions performance of the tuned vehicle. Recall the VW diesel scandal... those vehicles were factory tuned for improved performance and economy vs. a true EPA compliant tune, they certainly were nowhere near "rolling coal" tunes, and IIRC, the "cheat tune" could emit up to 40X the legal amount of NOx. Without data, we won't know how bad (or not bad) a given tune is, but I struggle to accept that there's overlap between "responsible tuners" and what is a probably a >40X increase in emissions. (Unless you're going to argue that the aftermarket 'dad's truck' tune is more conservative than the OEM cheaty tune that VW put out...which is possible but very unlikely.)
You are not incorrect. I'm sure Dad's tune is likely outside the emissions spec for 04, but you have to look at it in perspective. The max allowable of any given emission component set by the EPA and/or CARB allows for a HUGE margin of emissions. Like my HC emissions on my 96 Impala SS were in the mid 80s ppm but the max allowable was 363 ppm. Actual emissions from a tailpipe can change wildly with small changes to engine parameters, but if you failed (for instance) the HC portion of a smog test, it means something is way off.
People tend to think of emissions as a linear thing, but it isn't. It's not as if you pass a smog test if you're only within 5% of EPA/CARB limits. The limits are huge, sometimes 200-300% higher than what you're actually putting out. Dad's truck might be putting out 300% more NOx than it did in stock form, but that doesn't mean it is out of compliance based on the allowable limits.
The question basically comes down to legal/permissible vs moral/ethical in some of these situations. Having never put Dad's Dmax on a sniffer, I have no idea if it conforms to either legal limits or moral ones. My point was more to differentiate between performance/mpg tunes and coal rollers.
The other thing that so many people don't get (excluding most of us car-loving folks) is that you only notice the bad apples and therefore conflate them. I was with an environmental-nut friend who wanted to try out my new-to-me Mercedes. We were on the 110 in the valley. Directly in front of us was a Bluetec Benz. A couple cars ahead and in the right lane was a TDI. There was an F250 behind us with a Powerstroke. In the HOV lane, an older Benz diesel cruised by leaving little wisps of black smoke and my friend launched into a tirade about how diesel is awful and it's guys like HIM that ruin the environment for all of us.
I politely pointed out the three other diesels around us... not to mention the OM606 diesel he was currently driving in my car. He didn't notice the fact that he was surrounded by diesels (and driving one) and therefore didn't even know they were diesels. He instead saw the old diesel and pointed it out as evidence that all diesels are awful.
There's a term for it in film/theater called "The 3-sided wall," which is a variation on the "Tilt." It's when someone comments, notices, or becomes irked at a flamboyantly gay character without realizing that half the people on the stage/screen are homosexual. They just notice that the CHARACTER is gay, regardless of the orientation of the actor playing it. Same goes with diesel. You only see the obvious diesel and conflate it without realizing that there are dozens of diesel cars around you that aren't playing a sooty character. Sometimes, including the very car in which you're sitting.