[ShaginWagon]

Just wondering what the accuracy of the onboard MPG computer is ? Does Nissan give any stats on this? I had a 500+ mile trip and did some testing. I reset the computer and drove a constant 80 mph for 1 hour and it gave readings of 24.5 mpg. I reset and drove a constant 65 mph for 1 hour and had readings of 27.5 mpg. I was very pleased with the results but felt that they were high. I was expecting around 20 mpg @ 80 mph, and 24 mpg @ 65 mph. I did not have time to refill the tank to get a manual calculation, but in the past; the best I have done was about 18 mpg with a 50/50 mix of city/highway. This was with A/C on (it was 100deg today), 89 octane gas and 1 passenger. I did just turn 7000 miles, maybe the engine has finally broken in ???

 

[Ctx]

Shaggin,

I can't help you on the mpg thing.. your numbers are much higher than what I get (around 24 at 60 mph) I do have a question for you.. have you noticed any difference between the 87 octane mpg and 93?

Also are you skulking around the Austin area? (Hook 'em Horns!)

C.

 

[Gonzo]

I have found the computer is within .2MPG of my manual calculations.... I don't reset mine though... just keep an on going calculation. So it doesn't agree per fill up but does with my manual average calculations since day one.

 

[gseepes]

My computer does a good job as well, within +/- 1 mpg. I get around 23 mpg on average. I do 650 miles a week, so I get to watch the mpg numbers alot. I have 65 miles each way, and I average 80 minutes, giving me an average speed of 50 (about an hour of 30-50 mph, and about 20 minutes of 75-80 mph). Very little stop and go driving. Only run 91 octane, with full synthetic. As far as running higher octane gas, take the taste test. See if you notice any difference. I felt that the higher octane gave me better throttle response, a little less hesitation from a start.
Enjoy.

 

[9495]

Check out this thread:
http://www.nissanmurano.org/forums/showthread.php?s=&threadid=4973
I've been keeping track of all my gas statistics from day 1. I guess I should probably send out a more recent spreadsheet, though. Haven't done that in a while...

I'm showing a -5% to 5% difference between the "actual" and computer readout usually. However, you have to remember that there is a variance with each pump you use to fill the tank as well. How accurate is the pump, how full does it actually make the tank before shutting off, etc.

I would say that over time it is "reasonably" accurate. I've had a couple fill-ups that were WAY off (27% being the worst by far) but I assume something weird was going on at those times. They happened with small fills, like 5 gallons.

 

[Eric L.]

Recording cruising speed MPG is purely academic, since it takes much more gas to accelerate up to that speed. So, the only way to get accurate MPG is to reset after you fillup and not touch the button. You'll find its pretty accurate at your next fillup, to 1mpg.

 

[hfelknor]

"Recording cruising speed MPG is purely academic, since it takes much more gas to accelerate up to that speed."

That's not necessarily true.
If you are on a long haul, like accelerate to speed and drive a constant speed for the next 3 hours, the gas used during acceleration is a nit.

Homer

 

[droo]

Over 30 tanks of gas, my average computer reading is 21.5 mpg. Manual calculations show a 20.5 mpg average. So my computer is consistently optimistic by ~5%.

I only see one instance where the computer showed lower than my actual mileage, all other readings showed higher than the actual mileage.

The largest difference between the two was about 2 mpg.

Highest mileage from a full tank was 21.79.

Lowest was 17.25, but that was the second tank ever. More recent lows are around 18.5, but that's pretty rare.