2007 Tahoe LTZ bad gas mileage
November 8th, 2010, 2:12 PM
#21
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davidrcaldwell: Welcome to the forum.
My 2007 got 11-13 in town and 17-20 on the road. Had 4X4 and 3.73 gears. Interestingly enuf, the guys w/ 4.10 gears were reporting better mpg. Something to do w/ putting the engine in its sweet spot per a guy at GM. Had a Superchips before the Cortex model and tried both the economy tune and the performance tune. Neither improved mpg but the perf. tune did seem to give it a little more grunt but req'd premium and that was back when that was over $4/gal. Sold the Superchips.
Oh yeah, if you have a powertrain problem and the dealer finds a program in the ECM, he could deny warranty. But it's easy to put the OEM tune back in. I've been told that if they really dig into it, they can tell it's had a program due to some artifacts left behind. STSqrl might be able to weigh in on that.
Check out Blackbear.
My 2010 gets slightly better in town which I attribute to the 6-spd.
My 2007 got 11-13 in town and 17-20 on the road. Had 4X4 and 3.73 gears. Interestingly enuf, the guys w/ 4.10 gears were reporting better mpg. Something to do w/ putting the engine in its sweet spot per a guy at GM. Had a Superchips before the Cortex model and tried both the economy tune and the performance tune. Neither improved mpg but the perf. tune did seem to give it a little more grunt but req'd premium and that was back when that was over $4/gal. Sold the Superchips.
Oh yeah, if you have a powertrain problem and the dealer finds a program in the ECM, he could deny warranty. But it's easy to put the OEM tune back in. I've been told that if they really dig into it, they can tell it's had a program due to some artifacts left behind. STSqrl might be able to weigh in on that.
Check out Blackbear.
My 2010 gets slightly better in town which I attribute to the 6-spd.
November 8th, 2010, 9:04 PM
#22
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Welcome to the forum.
First you need to keep track of miles and gallons at each fill-up and do the calculations. If that confirms you're getting single digit mpg, then you have a problem somewhere. I assumed you are talking about sensible speeds.
First you need to keep track of miles and gallons at each fill-up and do the calculations. If that confirms you're getting single digit mpg, then you have a problem somewhere. I assumed you are talking about sensible speeds.
November 9th, 2010, 12:27 PM
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I have an 07 Z71 LT3 with 4.10 gears and before I modded it I was getting ~16 mpg in town and ~19 mpg on the highway (65-70 mph).
Now with level kit and larger MT tires, I am getting ~14 mpg in town and ~16 mpg on the highway. However, the speedometer has not been corrected for the larger circumference of the new tires.
Now with level kit and larger MT tires, I am getting ~14 mpg in town and ~16 mpg on the highway. However, the speedometer has not been corrected for the larger circumference of the new tires.
December 6th, 2014, 12:51 AM
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2007 Tahoe mileage/ altitude issues
I bought my 2007 Tahoe LT new and it got 21 town/27 hwy. When I took it in for the 39,000 mile service, the next tank came in at 12.6mpg!
I have complained to the dealer a lot!
He says it's normal. Last summer we drove to Aspen and the mileage had a linear increase to 21/27 at 12000 ft. Then back to 12/14 back at houston sea level. A mechanic told me there was a sensor insinside the engine or somewhere hard to get to that corrected for altitude. Seems to me it had to be ok, and the computer was just using this linear change incorectly. Any one else have this finding?
I have complained to the dealer a lot!
He says it's normal. Last summer we drove to Aspen and the mileage had a linear increase to 21/27 at 12000 ft. Then back to 12/14 back at houston sea level. A mechanic told me there was a sensor insinside the engine or somewhere hard to get to that corrected for altitude. Seems to me it had to be ok, and the computer was just using this linear change incorectly. Any one else have this finding?
I recently purchased a 2007 Tahoe LTZ. It's in excellent condition and under 48,000 miles. After a couple of weeks of driving, our in-town mileage was coming in at about 11 MPG in town and 15 MPG on the highway, a good bit lower than the 15 and 20 advertised. We have driven extremely conservatively, keeping the engine from going much over 2,000 RMP's, etc. Granny would be proud. Upon complaining to the salesman, he indicated this was very poor and to get it into the service dept. The service dept. determined that since there were no error/warning lights on, there was nothing wrong with the vehicle. They claim to have done a diagnostic check to be sure that all sensor input is correct to the computer, etc. They then spent no small amount of time convincing me that the heavy-duty towing package with it's 3.73 rear-end and transmission cooler combined with the 20" tires puts this mileage right where it should be.
I'm wondering if anyone is having the same experience or if I should push back?
I'm wondering if anyone is having the same experience or if I should push back?
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