I have discovered something on my 2007 Tahoe, and to be honest I think I am going to be a a little disappointed. I have owned several cars with the average MPG calculator, and they have been really accurate. My previous car for example over 100,000 miles, 367 data points the MPG is within .04 average, same goes for the gallons used in 100,000 miles it is within 11 gallons, which is close to 0.2% accuracy. (Long story short, I have a list and I track of the miles, the actual gallons and the gallons used for every fill up, I also track MPG in by the temperature, when it gets colder vs hotter etc.)
My LTZ however, is seemingly becoming a different story. Right now If I take the average of 8 fill ups (maybe not enough to really get an accurate reading) The Actual gallons used divided by miles is 18.45544 The Average from the PCM is 18.72449. The total difference of gallons used is 1.815 for 2331.2 miles.
Now this may seem petty to ask about .26905 average difference. If it is consistent with others, then I will not overly concern myself, however if others have found that their MPG is spot on, then I may have to look into why.
There is a few things that it could be
1) it could be the Gas stations cheating me out of gas... which would not be consistent with my other car.
2) It could be faulty readings from the PCM, which may be more sinister than it sounds.
3) It could be a leaky injector or leaking injectors, I would have to do a pressure test to see if the system lost pressure.
I cannot think of anything else it could be at this point...
John
My LTZ however, is seemingly becoming a different story. Right now If I take the average of 8 fill ups (maybe not enough to really get an accurate reading) The Actual gallons used divided by miles is 18.45544 The Average from the PCM is 18.72449. The total difference of gallons used is 1.815 for 2331.2 miles.
Now this may seem petty to ask about .26905 average difference. If it is consistent with others, then I will not overly concern myself, however if others have found that their MPG is spot on, then I may have to look into why.
There is a few things that it could be
1) it could be the Gas stations cheating me out of gas... which would not be consistent with my other car.
2) It could be faulty readings from the PCM, which may be more sinister than it sounds.
3) It could be a leaky injector or leaking injectors, I would have to do a pressure test to see if the system lost pressure.
I cannot think of anything else it could be at this point...
John
