Ive been checking around on the site seeing what the average drivers MPG readings are. I really dig the fuel econony mode of that left most gauge in the center gauge cluster.

Anyway, my point is, my gf's 350z (i own a 3000gt, lol) reports INSANE fuel economy. I don't think she ever resets the thing, I don't think she's as familiar with the features of that gauge as I am (i love playing with it). Today, before I reset it, the average was 52mpg!!! And that's with THOUSANDS of miles on the car. I haven't read the manual, but I assume the top number is the lowest recorded instantaneous mpg? It read 3.1mpg before I reset it, which sounds believable, that's probably from romping on it.

After I reset it today and drove for a while, even decelerating and taking off from a stop, my lowest recorded MPG was about 29mpg, and I had the average up to 47 after an hour or two of driving.

Is this even possible? Or is her thing messed up? I probably know the answer, cuz I'm sure as hell not getting over 600 miles to the tank, but I do get WELL over 400.

 

52mpg is rediculous, get real. You would have to be living in an Escher drawing where you continually drive downhill for your whole life. Obviously there is either error with the equipment or ... ahem... the operator.

 

lol, I can operate it just fine thank you

but I agree the numbers seem a little ridiculous, I wonder whats causing them. The instantaneous figure seems to read appropriately, but the average is always VERY high

 

Apparently, if you have a manual, you can go to the top of a hill, put it in neutral, reset the mpg, and when you start to roll down, it will shoot to 90+...take a pic and brag to your Honda friends.

(slightly off topic)

 

mines been at 16.6mpg for about the last 1000 miles.

 

i know... me too... i havent driven too much highway lately =/

 

The instantaneous MPG and the average MPG are from two displays? For the average MPG, it is displayed on the top and it is updated every few minutes, and the bottom is the average speed. Not sure if you are referring to this bottom number for the average MPG.

 

Correct! The top number on that display is the average MPG since resetting. The bottom number is your average MPH since resetting.

 

Thats not realistic. Although mine has been a 22.3 for a while. Not bad i suppose. But i usually drive 10 miles on the streets everyday.

 

mine stays at 23, daily driver 80 miles plus, unless I really take it easy, then it goes to 23.5

 

being a little geeky i've let it go the whole tankful a couple of times and it generally reads + .2 above calculated mpg ( indicates 24.9 while the math says 24.7 )

at 70 mph for 10 miles (flat fla) ~31.3 mpg
at 75 mph for 10 miles (flat fla) ~30.5 mpg <-- all last weekend while driving
at 80 mph for 10 miles (flat fla) ~28.7 mpg to/from scca auto X (a/c on)
at 85 mph for 10 miles (flat fla) ~26.4 mpg
at 90 mph for 5 miles (damn traffic) ~24.8 mpg

during auto x ~5.6 mpg [plus one severe tossing of car off runway into deep weeds]

'but officer, i was doing research' would have gotten me out of a ticket don't you think...

not as good as my wifes honda civic hybrid (44mpg) but the Z has 1 or 2 other saving graces i guess

after auto x and 60 mile drive home filled it 17 gals - that with fuel lite on for 30 miles, DTE flashing --- at me, gas gauge pegged low yet still have 3 gals in tank? i know i don't want any of the floaties in the last gal but should have near 50 miles before needing to call AAA - could be a little more accurate is all i'm whining about :-)

 

Ooohhh, the bottom number is average speed? Well that makes the numbers make more sense, lol. I swear it says MPG next to it, not MPH, lol, guess I'll have to take a harder look next time im in there.

so the top number is the average mpg? She must really step on the gas then, cuz it said 3.1 before I reset it, hahaha, and thats after thousands of miles.

 

Hehe definitely something wrong with that, I've actually tried to trick the computer to put out a crazy number like that. Best I got was 32 while reseting it on the freeway at 65mph. With my style of daily driving I read 20mpg consistently since I've got it. To me that sucks, I was thinking of getting a drop in filter or a pop-charger to increase my mpg. What would work best? I'm not into performance as much as I used too, saving money is my main concern now. 150+ a month for gas, man thats more than my insurance

 

Hehe... that's why i said

 

if you reset it goin like 75 on a flat surface or downhill.. you get a pretty high number.. i got 61mpg once... of course when i started goin up hill it dropped to like 22

 

Idling will give you terrible gas mileage too... gas mileage = (miles driven)/(amount of gas used). Idling gives you 0 mpg... so don't let your car idle when it is unneccessary. Warming up the motor only takes about a minute.

 

When idle, revs are so low. Less fuel is being combusted, so no need to freak out. lol.

 

So sad....3.1mpg . This is the kind of abuse that the Z has to endure from some female drivers lol kidding.

 

Cool info. I've done a test like that with my car when I first got it and had similar results. It seems like the speed for achieving the best MPG is cruising at 45 in 6th gear. I think the MPG computer reading is pretty accurate when compared to regular math cal., as it is most of the time off by +/- .2, worst being .4 miles per gallon.

 

My average is stuck at 17 and my instantaneous is stuck at 13 which will be my only complaint when I take my new car in for maintenance once I get a thousand miles on the thing and I feel break-in is done.