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UFO · 08-06-2015, 11:14 AM

Be wary of OBDII tools, especially the ScanGauge. The Chrysler designed CAN bus is very busy, and adding tools into it via the OBDII port often causes the transmission computer to trip out. It can be disconcerting to have shift points disabled while driving.

A 2006 CRD probably does not have the original shift points. They were "upgraded" due to the torque converter being inadequate to handle the low rpm torque of the diesel engine, that could be one contributor to your poorer fuel mileage. I had a 2005 model with the lower shift points and routinely got 30mpg on the highway, if I kept speed at 65mph or below, making sure the tranny was locked in top gear - for the old shift points this happens at 57mph, later flashed up to 61mph.

Make sure you have a clean air filter. The CRD has a very small filter, same size as the 3.7 gasser and should be changed often, sometimes less than 10k mile intervals.

08-06-2015, 11:14 AM	#6 (permalink)
UFO Master EcoModder Join Date: Sep 2010 Location: Denver, CO Posts: 1,300 Colorado - '17 Chevrolet Colorado 4x4 LT 90 day: 23.07 mpg (US) Thanks: 315 Thanked 179 Times in 138 Posts	Be wary of OBDII tools, especially the ScanGauge. The Chrysler designed CAN bus is very busy, and adding tools into it via the OBDII port often causes the transmission computer to trip out. It can be disconcerting to have shift points disabled while driving. A 2006 CRD probably does not have the original shift points. They were "upgraded" due to the torque converter being inadequate to handle the low rpm torque of the diesel engine, that could be one contributor to your poorer fuel mileage. I had a 2005 model with the lower shift points and routinely got 30mpg on the highway, if I kept speed at 65mph or below, making sure the tranny was locked in top gear - for the old shift points this happens at 57mph, later flashed up to 61mph. Make sure you have a clean air filter. The CRD has a very small filter, same size as the 3.7 gasser and should be changed often, sometimes less than 10k mile intervals. __________________ I'm not coasting, I'm shifting slowly.