Will they do anything?
12-18-2007, 09:40 AM
#41
Senior Member
Join Date: Aug 2007
Location: Florida
Posts: 607
Instead of hijacking blackmax07's thread with "I get" posts, all of you guys can post those in the new MPG thread for 07-08 Maxima owners that I started (http://forums.maxima.org/showthread.php?t=548329).
12-18-2007, 10:18 AM
#42
Note that all of the above numbers are from the computer and not calculated by me. I believe, calculating mpg as total miles travelled divided by amount of gas filled is not as accurate as the computer.
I also noticed that running the a/c, heater, front windshield defroster decreases mpg.
I also noticed that running the a/c, heater, front windshield defroster decreases mpg.
12-18-2007, 10:51 AM
#44
I reset my computer everytime, and I still get different numbers EVERY time I calculate vs the comp.
12-18-2007, 10:55 AM
#45
Senior Member
Join Date: Aug 2007
Location: Florida
Posts: 607
The computer is WAY off at times it is as much as 2mpg off sometimes more. It's not hard to divide the miles driven by gallons. That is actually the ideal way and MOST accurate.
I reset my computer everytime, and I still get different numbers EVERY time I calculate vs the comp.
I reset my computer everytime, and I still get different numbers EVERY time I calculate vs the comp.
12-18-2007, 11:00 AM
#46
I don't know what you mean.
The actual miles I've driven divided by the gallons filled = my MPG, the computer doesn't measure it this way. It basis it on how you've been driving, so unless it's reset at every fill up, it's less and less accurate. I find that even with every fill up and reset, I still get varying numbers from manual calculation.
The actual miles I've driven divided by the gallons filled = my MPG, the computer doesn't measure it this way. It basis it on how you've been driving, so unless it's reset at every fill up, it's less and less accurate. I find that even with every fill up and reset, I still get varying numbers from manual calculation.
12-18-2007, 11:15 AM
#47
Senior Member
Join Date: Aug 2007
Location: Florida
Posts: 607
I don't know what you mean.
The actual miles I've driven divided by the gallons filled = my MPG, the computer doesn't measure it this way. It basis it on how you've been driving, so unless it's reset at every fill up, it's less and less accurate. I find that even with every fill up and reset, I still get varying numbers from manual calculation.
The actual miles I've driven divided by the gallons filled = my MPG, the computer doesn't measure it this way. It basis it on how you've been driving, so unless it's reset at every fill up, it's less and less accurate. I find that even with every fill up and reset, I still get varying numbers from manual calculation.
I do not understand what you mean by "It basis it on how you've been driving, so unless it's reset at every fill up, it's less and less accurate." How does "how you've been driving" influence the MPG calculations in the computer?
12-18-2007, 11:43 AM
#48
Computer is cumulative, it's not dynamic.
The exact miles driven divided by gallons filled is spot on accurate on every full fill up. Can you proove otherwise? It wouldn't be if and only if, the car didn't fill up to the same point everytime, which for all intents and purposes, it should.
For your next few fillups do it both ways, see if they are the same.
The exact miles driven divided by gallons filled is spot on accurate on every full fill up. Can you proove otherwise? It wouldn't be if and only if, the car didn't fill up to the same point everytime, which for all intents and purposes, it should.
For your next few fillups do it both ways, see if they are the same.
12-18-2007, 12:00 PM
#49
Senior Member
Join Date: Aug 2007
Location: Florida
Posts: 607
Computer is cumulative, it's not dynamic.
The exact miles driven divided by gallons filled is spot on accurate on every full fill up. Can you proove otherwise? It wouldn't be if and only if, the car didn't fill up to the same point everytime, which for all intents and purposes, it should.
For your next few fillups do it both ways, see if they are the same.
The exact miles driven divided by gallons filled is spot on accurate on every full fill up. Can you proove otherwise? It wouldn't be if and only if, the car didn't fill up to the same point everytime, which for all intents and purposes, it should.
For your next few fillups do it both ways, see if they are the same.
I think the manual method of calculating MPG is not accurate enough not because there is anything wrong with the formula but because one cannot provide exact numbers for the total gas used for the total miles travelled. Most people do it this way: they fill up the tank to the full, then they drive for some, say m miles, and then again fill up the tank to the full, with say g gallons of gas. The MPG then is m/g. Clearly, there is no problem with m. There is a problem with g because a number of factors influence how much gas is actually going in when one fills the tank to the full. Such factors include weather conditions, how hot/cold the car is, whether someone is trying to force more gas in or not, and so on. The computations from the internal computer is free from such factors.
