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UFO · 11-28-2011, 06:15 PM

No baselines yet. I had my device miswired, and managed to borrow an oscilloscope to troubleshoot; it seems to be working properly now.

The first thing I have noticed is the engine warm-up is MUCH slower. I am usually up to temperature within 5 miles of driving my commute, but with EGR disabled it takes almost 10 miles of driving.

My baseline will have to involve plugging in the block heater. Obviously the EGR cooler does a considerable amount of preheating the coolant before the engine is warm. Maybe a judicious reroute of the exhaust through the cooler back into the exhaust (instead of the intake) is in order; this could ensure a fair FE baseline, but is a complex endeavor.

I think I have hit on the reason most people claim defeating the VW TDI EGR will reduce fuel economy.

11-28-2011, 06:15 PM	#2 (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	No baselines yet. I had my device miswired, and managed to borrow an oscilloscope to troubleshoot; it seems to be working properly now. The first thing I have noticed is the engine warm-up is MUCH slower. I am usually up to temperature within 5 miles of driving my commute, but with EGR disabled it takes almost 10 miles of driving. My baseline will have to involve plugging in the block heater. Obviously the EGR cooler does a considerable amount of preheating the coolant before the engine is warm. Maybe a judicious reroute of the exhaust through the cooler back into the exhaust (instead of the intake) is in order; this could ensure a fair FE baseline, but is a complex endeavor. I think I have hit on the reason most people claim defeating the VW TDI EGR will reduce fuel economy. __________________ I'm not coasting, I'm shifting slowly.