GM 0411 quick question

[2xls1]

It's not the PCM box itself but the calibration operating system it is flashed with. There are lots of different model and type vehicles that could be flashed in that 0411 PCM. That is what determines if it has lean cruise capabilities or if it is enabled. As a rule the EPA did not allow GM to enable LC on domestic made for USA vehicles for emissions reasoons. Some GM Austrailian made Holdens had it enabled. There are ways to enable it though on certain calibrations if it is available and not enabled. Again it depends on the operating system. And don't expect to gain much in MPG with it enabled.

[dfarr67]

Yes, he said properly tuned the 0411 will return very good mileage. My EBL has the hwy mode enabled and does well.

[Fast355]

I have used actual lean cruise in TBI ECMs, TPI ECMs and the EBL as well as with the 0411. I have also used open loop pseudo lean cruise calibrations in vehicles that did not support lean cruise like my Hemi Ram. I have found that well tuned lean cruise will often return 10-15% better fuel economy at steady cruising speeds than without. That is running 16-16.5:1 air/fuel ratio with a bump in timing as the slower burn of the lean mixture can often result in the need of 4* or more timing added. Furthermore running on the lean side of stoichiometric will actually drop EGTs. A good example of this can be found in most aircraft pilots manuals with information on setting cruising air/fuel mixture. Most information out there has a pilot adjust to find peak EGT (which is at stoichiometric) and then further lean it 25-100*F. On an air cooled airplane substantial reduction in cylinder head temperature is also noticeable.

For example one such study can be found here.
https://docs.lib.purdue.edu/cgi/view...xt=techdirproj