So there we were, nearly three years after the release of the LML Duramax and still no power-adders we would consider groundbreaking. Unlike its predecessors (the LB7, LLY, LBZ, and LMM), the LML is yet to be supported by EFILive, the custom-tuning tool of choice for maximizing power in ’01 to ’10 GM trucks. The fact that the Bosch CP4 used on the LML flows roughly 30 percent less fuel than the CP3 found on earlier generations also raised some legitimate concerns in making more power. Would the latest and greatest Duramax be able to match the tune-only, 500-rwhp threshold that previous versions could? And even if it was possible, would the diesel particulate filter (DPF) have to be removed to get there?
| Emissions Friendly Tuning Gmc Sierra On Dyno
After hearing the folks at Calibrated Power Solutions (parent company of Duramaxtuner.com) were developing DPF-on performance tunes for the LML, we paid them a visit, seeking answers to all of these questions. What we found was promising news for anyone who wants to add considerable power to his or her ’11 to ’13 GM, yet doesn’t like the idea of tampering with emissions equipment. As it turns out, the company’s Race tune makes just shy of 500 hp at the wheels, a Sport Economy tune is good for about 475 hp, and the stock Allison 1000 transmission is so far keeping pace—a first for the Duramax segment. This means you may no longer have to fork over $5,000 to $6,000 for a transmission build before running the hottest tune in your arsenal.
"The DPF isn’t as much of a power-robber as most people think.
— Nick Priegnitz"
As far as the effect of its higher-horsepower tunes on the DPF, we were pleasantly surprised with what the company had to say: “The DPF isn’t as much of a power-robber as most people think,” said Nick Priegnitz, Calibrated Power Solutions’ owner. “We’ve only seen a 10 to 15hp difference on the bigger tunes.” After spending a day at its Union, Illinois, facility, we’re sold on what could easily be the wave of the future for DPF-era diesel enthusiasts: making emissions-friendly power.
A Second Opinion Power To form our own opinion, we borrowed this ’12 Chevy Silverado 2500 HD for testing purposes. Prior to being treated to the Sport Economy tune, we have to admit the truck felt lazy. Granted, we don’t drive many bone-stock trucks anymore, but the big Bow Tie didn’t feel light on its feet by any means: The accelerator was stiff and the truck was so upshift happy it almost seemed underpowered. Once tuned, throttle inputs were more sensitive, the truck seemed more eager to run, and we could definitely feel a seat-of-the-pants improvement. Driveability increased tenfold, and it was much more fun to be behind the wheel. And, of course, it was smoke-free at the tailpipe.
| Emissions Friendly Tuning 2012 Chevy Silverado 2500hd
MPG
On a 100 percent highway trip up to Calibrated Power Solutions’ facility in northern Illinois, we hand-calculated 17.04 mpg in stock trim. The return trip (on the Sport Economy tune) produced a similar number (16.7), despite running through a full regen cycle. While we were hoping to see a bump in fuel economy, the fact that we had considerably more horsepower on tap yet weren’t accumulating soot any quicker in the DPF, was comforting. According to Priegnitz, the DPF-on tuning will really shine in city and short-trip driving. His ’11 test truck, which is used for a 12-mile commute to work, went from 11.5 mpg to 13.7 mpg while running the Sport Economy tune.
