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2012 RAM 1500 - Computer adjustment for MPG

Hi, I was told that I could have my vehicle computer adjusted for fuel enconomy between city and hyway driving that would automatically adjust once you go from city to hyway speeds so that I can have better fuel economy?

OK , who told you that ? And just how much of your wasted money did they want?


The computer in your truck already adapts to different types of driving. If you want the fuel economy display to show city or highway fuel economy exclusively, push the reset button before each journey.

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If the computer could be adjusted for better fuel economy, don’t you think the manufacturer would have already done that?

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Generally not. The OEM’s do their best to maximize fuel economy when they design the vehicle as they have to meet CAFE standards. If they could do so without adding cost or weight (we’re talking about ECU programming, so no new parts and not much cost), they would be all over that at the factory. Car companies are known to spend millions chasing a tenth of an MPG improvement.

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Just enjoy the historically low gasoline prices. Dodge already did the job for you.


Pure hokum.

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To paraphrase the Packard slogan… Ask the man who told you.

Reminds of some of the products advertised in the fifties and sixties. Sintered bronze oil filters that eliminated engine wear, toilet paper oil filters. Gadgets that would improve both performance and gas mileage.
Of course we can’t leave out Blinky the Cat, that sat on the package shelf in the back window, was wired to the turn signals and his eyes would blink with the signals.

Yes, but as tacky as that “cat” was, at least it worked–unlike the belief that the OP’s ECM can be adjusted.

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I imagine they were referring to a tuner that plugs into the OBD 2 port, enabling you to adjust some engine and transmission parameters. These devices only work when they are plugged in; they do NOT change the programming of the actual vehicle computer. They are also virtually useless for a normally-aspirated gas engine. Because they can change turbocharger boost levels (to a point), they can increase the power of turbo-diesel engines, which is where they are most often used. Engine longevity is the likely trade-off.

Your best bet is a finely calibrated right foot.

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They most certainly do change the programming of the vehicle computer. They download a revised set of calibrations the computer uses to control the engine and transmission. You plug them in, they connect with the ECU and overwrite the cals that are there. Unplug when finished and away you go.

That, however, is true. Changes can be made to ignition timing, variable valve timing, full throttle air/fuel ratio, automatic shift points and pressures, rev limits and more. With premium fuel instead of regular, it is possible to gain maybe 10% HP on some NA engines, far more on turbo engines by increasing boost.

Better economy… not so much. You can increase the spark map but that just means you hit the knock sensors more. You can set the part throttle shift points lower but that lugs the engine.

Absolutely agree with that!

Well, you’re both right. There are those $59.95 plug in “chips” on the “we have chips for every car” web sites that just maybe modify while they’re plugged in, while the more serious and expensive ones actually do modify computer set points.

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Yes, I was thinking of the cheapo ones.

Only if it has an ECO mode button like more recent models . A lot of FCA models have that now .