I would think that since cooler air increases the effective compression ratio, this would also increase fuel economy. After all, there is a reason the turbo charged air is run through an intercooler.
Quote:
Originally Posted by mechman600
A bit of a side note. Unplugging the intake manifold temp sensor and installing a resistor to make the ECM think it's cold advances the timing on some engines and does wonders for mileage. I repeat: SOME engines. Cat engines: 100 ohms = indicated 7F. Cummins I'm not sure, but I could easily find out.
|
Old post, but I would be VERY interested to know if the Cummins can be hacked with this easy mod and get good results.
Quote:
Originally Posted by mechman600
A mechanical adjustment depends on the year. 12 valve B5.9s: yes. Big difference. 24V electronic ISBs: no point. The timing is electronically controlled in the VP44 injection pump. Adjusting the mechanical timing of the pump won't have much of an effect. I know some aftermarket tuners only alter fuel metering while others alter both metering and timing. For economy you would obviously want the latter. I would go with a tuner before tinkering with various resistors in place of sensors with the Dodge. On the other hand, resistors are really really cheap.  |
I've got a VP44/ 24V ISB, and a Juice With Attitude tuner that I have heard can improve both power and fuel economy. The problem is, I have also heard a handful of stories that the moment someone tapped the fueling input with a tuner, the VP44 gave up the ghost. This could just be coincidence since those things are failure prone, especially given the notoriously awful lift pump.
That said, I have always been chicken to tap the line for fear of being out $2k on a pump. Also, my transmission has been on its last leg for 40k miles, and I didn't want to put a nail in the coffin... I'm starting to get curious again though. Maybe if I just treat the throttle gently
Quote:
Originally Posted by JasonG
Looks like my weekend trip agrees with your statement.
When I got in my wifes car the MGD was showing 46mpg, normally it hovers around 44.
The trip (with me driving) was 48 range.
Looks like the warm air intake stays for the winter and the
Snorkle gets reconnected come summer.
|
Perhaps the snorkel adds drag, which by removing, bumped your MPG. While I appreciate that you reported the numbers, there are too many variables at play for me to conclude that warmer air was the primary factor for the improved mileage.
I'm always more interested in the deductive reasoning behind why something behaves the way it does, and less interested in the inductive reasons. Anecdotes fall into the inductive category, and while valuable and worth consideration, always leave room for uncertainty.