ReservoirD

Look, I know this has been well beaten in the mileage threads, but what I want to know is this: does anyone, anyone at all, have a trip computer that is accurate, or close, or underestimates mileage?

Mine averages 4+ MPG over what I actually get. It strikes me that if ALL of the computers are overestimating by roughly the same amount, they are not malfunctioning as much as it would seem. That would indicate that Nissan intentionally sets them to overestimate the gas mileage of this car, rather than to be an accurate guage.

Cheers.

Eleebob7

Yeah mine's like that too. Except when i have pure freeway driving. Then, it's about 9-12 mpg over. Good to know i'm not the only one w/ the problem. I asked the dealer about it and he said that their computer's were accurate... (thinking to myself BS)

Virus

iTrader: (1)

My Dodge Durango's computer is only .5 miles off at the most. My Maxima is consistantly 2.5-3 mpg off.

F8Lmax

Mine seems fine. You have to make sure you are clearing it out everytime you refill, otherwise it will be the average over several tanks.

Virus

iTrader: (1)

If this is indeed true it'll be the first. Everyone elses Maxima seems to be 2-5mpg off from what the computer says.

koostermax

it's nissan's way of saying "look it does pretty close to the EPA of 28 mpg highway".... almost a fancy way of saying, the computer says so, so it has to be what it is.

wild willy

iTrader: (10)

I have the Altima 3.5 so I am assuming it is basically the same set up. Mine is usually 2-3 mpg optomistic. However, I do mostly city driving and on my last tank the trip said 23.9mpg and the fill up told me 27.5mpg (that was a first)

I have taken one highway only trip and it was dead on. If you do mixed driving it is not all that accurate

soundmike

iTrader: (24)

First of all the computer is inaccurate only because it averages very frequently and is very sensitive to throttle position to get the calculations right (as you'll see in the DTE #'s over the course of 10 minutes in a granny-type and enthusiastic driving).

That much said i only rely on the DTE when highway driving w/ cruise on and occassional overtakes here and there. During long drives it's right on the money as far as accuracy goes, the DTE on my last trip coincided with the manual calculations i've made every fill-up +/- 1MPG.

EPA estimates on mileage is also very accurate as far as i can tell. I have an auto and again during that long trip i've managed to get 520 miles to the tank with a little gas to spare.

On all-city driving in downtown Houston i barely manage 20MPG however.

slickrick

iTrader: (12)

i just took two 300 mile trips in my 2k2 and the computer said i got 28.5 mpg's. i actually got around 19-20. i was averaging 85 mph but with stints up to 110 a few times. but still, under 20 mpg is not good for highway miles.

ReservoirD

I don't want this thread to be a discussion about mileage at all, just about what the computer says vs. what reality is.

Of those posting on here, I'd say over 90% have reported that the computer is high by 2-4 MPG. If this is the case, the computer is fairly accurate; it's just set to register higher mileage than the car actually gets. If it will register, in general, 2-4 MPG (a two MPG range) better than reality, it could just as easily provide a range that has the actual mileage somewhere in the middle (in most cases).

So let's break it down: in your experience, what does the trip computer register v. reality? Mine is, averaging the last seven tanks, more than 4 MPG optimistic.

Jaws

I don't think the odometer is accurate either. By using a GPS over the course of a 100 mile run (according to the GPS), the odo read 104.5 mi at a constant 75 mph. Also, around here there are calibrated road markers to test odometer accuracy. The odometer is always reading lower that the actual calibrated distance by about 4-5% which is consistant to the results I got with the GPS.

spta97

iTrader: (1)

I wish my old Durango would have lied. Ever see it when it says 6 MPG??? Truth hurts!

kway007

I haven't had my I35 long enough to gauge whether the MPG is right, but I do know that the avg MPH is *wrong* by exactly 5MPH. If I set the Cruise to exactly 70 and reset the Avg MPH, it shows 65 MPH. No matter what I set cruise at, the trip computer says 5MPH less. Anyone else have this happen? I wonder which is wrong, the trip computer or the speedometer?

Also, if the avg MPG is wrong, how accurate is the DTE? Is it based on some larger, lifetime avg MPH, or is it just as volatile? I dont plan on relying on the DTE completey, but it would be nice to know that it isn't overstating the remaining DTE by too much.

haganjeff

I agree. 2003 SE- computer says 26 mpg on almost every tank. Actual is somewhere in the 23 range. Glad to hear this is happening to others. The avg mph is off about 3 mph when cruise is set. Interesting!