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I live in a small town in Tennessee, and have a Monte Carlo (2003, 3.4L 90K.) and a LeSabre (2000, 3.8L, 150K).

My commute is 68 miles one way down two lane highways. I drive the buick for this most of the time, and get about 27 mpg, shifting at 2000 rpm, with no coasting. The monte, gets about 26.5 mpg, but the converter, although the same as the buick, is setup to lock up at about 2500 rpm.

Both cars have a K & N, and I did notice a noted gain in the Buick (2 mpg), but more of a performance gain in the Monte.

Where to begin??

Thanks for this forum. It is a worthwhile undertaking.

Welcome to the group! Your numbers are good already. You may be able to raise your mpgs further with help from people here.

http://www.cleanmpg.com/forums/showthread.php?t=1510 is always a good place to start.

Welcome, kermistang86!
Your MPG numbers are certainly better than what most drivers would realize in those vehicles, but I'm sure you're looking for "more". And so you came to the right place. You will meet many friends here and will get lots of advice.
I've driven dozens of GM cars over the years, and I can say that you can easily push those current numbers up by at least 10%. Here are my suggestions -
- Considering increasing your tire pressure to the number shown on the tire's sidewall as the maximum. Not everyone feels comfortable with this idea, but I run my cars with tires at that pressure and I find the car handles better with a bit more active ride, and the tires last more than twice as long.
- Accelerate gently and let the car shift to top gear as soon as possible. GM's pushrod engines love to loaf along under 2000rpm, and keeping them around 1500 (roughly 50mph) yeilds incredible (for the engine and car size) results.
- Both transmissions are electronically controlled and are adaptive - they learn how you drive and adjust shift speed and firmness accordingly. After a week or so of hypermiling, you will find the transmission will 'act' differently. In my Chevy Maxx, for instance, I can accelerate from just above 20mph in 3rd gear- with the converter locked! I have to press the accelerator down almost half way to unlock the converter. The computer learned over time that I have a very gentle foot on the accelerator and it responded with lower shift points and a more aggressive application of the converter clutch.
- Learn about DWB - "Driving Without Brakes" and DWL - "Driving With Load". The first involves coasting down toward intersections or traffic delays and keeping the brake application to an absolute minimum. The second involves keeping the engine load constant rather than keeping road speed constant. If your commute has rolling hills, let the car lose some speed going up and let it gain the speed back on the downside. Use gentle throttle to keep the transmission from downshifting or unlocking the converter.
- Consider purchasing a ScanGauge if your hypermiling efforts appear to start paying off. The SGii is an incredible help in refining the techniques you'll learn here, and will likely pay for itself over and over in reduced fuel costs. If either (or both) vehicles have an instantaneous fuel economy display (Shows as INST MPG in the display), you can use that as a rough guide as you're starting out with your new driving strategy.

Keep us posted on your efforts and results!
Chris