I have a technical question. I have a 2000 GMC Sierra with the 5.3l engine. One of the features is the ability to run the engine without any engine coolant. From reading the owners manual, it fires every other cylinder to keep the engine somewhat cool. I noticed that the new GMC Denali, 2006, has a simular feature to conserve fuel. I was wondering if I were to make the computer think that I had no antifreeze if I would notice and fuel economy differance. NO I won't drain my radiator but I was thinking mor on the lines of short circuting the temp sensor to the sensor that monitors the antifreeze level. Any comments??

It's called "Limp Mode." Cadillac has been offering it for years. It will certainly conserve fuel since the computer will not let the engine make more than just a few horsepower. You could achieve the same thing by never pressing the accellerator more than 5%.

Yep, try driving a heavy ass crewcab in limp mode. It feels like driving a 6000 pound electric golf cart.