not sure yet but EPA is 19 city / 26 hwy

 

First, it is probably best to wait on an answer on this until some owners have properly broken in their new cars. The real world MPG they get will not be evident until then.

Second: according to the sickers AT gets 19/26 and MT gets 20/27
I saw one of each yesterday at a dealer. According to the reviews in magazines, the tank is "huge" Most list it as 20 gallons but one listed it at 18.6 The difference might be that the 18.6 is usable the 20 is "bone dry" My F body has a 15.5 gal tank, but I have never been able to put more then 14.25 in except the one time I ran it out of gas.

So I guess by doing the math that gives you a minimum city cruising range of 353 miles. Highway is 483!!
I like that....

 

I only drove mine for about 30 miles yesterday, but the readout said something along the lines of 16 mpg. That was with a mix of city/highway driving.

Spencer

 

Took it home on a 450 mile journey from St George Utah, to Vegas, to San Diego.

Filled up 13.25 gallons, trip ODO was at 266, so MPG = 20.07, mostly 90 fwy cruising, some jaunts at 110, some at 60-80, a couple pit stops.

 

Just a note also on the milage. The milage estimates probably accurate for the city driving (for normal driving that is). For highway though, it's really based on the constant speed you drive. As an example, my Honda CRV is rated at 22/25. Having just driven down 1200miles from D.C. I can tell you, I was getting exactly 22mpg with cruise control at 70mph....and belive it or not, 30mpg with cruise control at 65mph. Granted, it probably due to the CRV's coefficient of drag ...but still the esimates on the stick are probably on the conservative side; so if you are on a long trip and drive normal cruise control...you should get better milage than the 26 listed.

 

right now iam at half a tank with a 170 miles on my lemans base, you figure!

 

On my first day's drive, I averaged just 14.5 MPG (yeah, I was having fun)! Then I reset the MPG meter and took a liesurely highway drive to work (70-90 MPH), largely in 6th gear. My average shot up to 25.5 MPG.

So it really depends on how you drive, and also as Radian says I think it will improve as the engine breaks in.

It's so nice to have all that neck-snapping power when you need it, but still be able to gently sip fuel for long trips and commutes. There's just no downside to this car!

 

Heh, in L.A. try around 14MPG in City Driving, kinda sucks. But I've been driving it, not flooring it mind you, but pushing it to 3.5K to 4K a lot of the time, it's too damn hard not to. I'm sure if you drive it a little softer its not too bad. P.S. anyone with the Z already check out the oil dipstick, kinda strange, has a bunch of twist and curls in it, I thought it was broke when I first checked it!

 

doesnt the z have a setting on the computer for "distance to empty"?
this would be the easiest to tell? i can guess it will change somewhat with your cruising speed, but should be close...

michael

 

The only way to truely measure the consumption rate is to first fill the tank (consistently -- if you stop on the first auto stop of the pump, do the same next time). Then zero your trip miles and drive as normal. Then on your next fillup, fill up the same way and jot down the gallons you pumped. Divide the miles on the trip with the gallons and you'll have an exact. The margin of error is very slim this way; the more you consume before you fill up the more accurate the measurement is. This is what I did when I did two full 350 mile legs (one at 65mph cruise control & other at 70mph cruise control).

 

I would hope the trip computer gives a reasonably accurate indication of fuel consumption -- otherwise what would be the point of it?

 

I would assume & hope it's accurate also, but the problem with it's accuracy is its only updated every 30 seconds; not a real time system -- I think I read this in the manual.

In the worse case, this means, theoretically, if you are driving at a very low mpg (say getting on an on ramp) and it snaps it at that moment with only say 1/8 tank left. Your miles until empty will probably be like 15; when in fact you really have another 100 on the highway -- but this will not be reflected until it gets another snapshot...

Hopefully the better case is, it's calculating the average over those 30 seconds and then displaying the average at the 30 second interval ...anyone who has the car can shed any light on these specifics; I'm truely interested...

 

Well, I have a little bit of light to shed on this subject. Those of you who have put 2-300 miles on your Z might have a little better understanding, but here goes. After putting about 40 miles on my Z on Saturday, the "dte" on the trip was 246 (with a full tank starting at 11 miles, 93 octane of course). Today I drove it another 50 or so (yes, a "Sunday drive"), mostly highway miles (had to show a 300ZX what was up at one point ) and the dte had changed to 276 by the time I got home. A lot of the highway miles were done in 6th gear, which definitely seemed to make a difference in the dte. I definitely didn't see any "jumping" as in your onrap scenario. The changes in the dte were pretty gradual. I would guess it is taking quite a few averages. At any rate, we will know how accurate it is once I go through this tank of gas.

Spencer

 

From what I can see by watching it, I'm pretty sure it is looking at the total miles driven since reset (which is also displayed), and the total fuel consumed since reset, then calculating MPG from that. It only updates the display every 30 sec so it's not jumping around all the time annoying you (flicking back and forth between 20.1 and 20.2, for example), but the overall values are what count.

This is the only reasonable way to do it, and it seems to be doing it this way. For example, when you floor it, the MPG doesn't drop way down to 3, and when you take your foot off the gas and coast, it doesn't jump up to 50. The more miles you have on the clock (i.e. since reset), the hard it is to make it move one way or another, which seems to confirm this simple formula:

MPG = total miles / total gallons

If you reset the meter, then drive really hard, you will get a very low MPG (I have done this). If you then drive for a while on the highway, it will slowly move up to a reasonable figure. Now if you drive really hard, it doesn't shoot back down. It all makes sense that it works this way.

 

This is great news then...sighhhh relief. From your comments, then it is not either of the cases I mentioned earlier.

There must then be an analog to digital conversion of the gas tank level measurement to do this -- possibly something to add to the digital gauge info.

 

My guess is that the engine management computer knows EXACTLY how much fuel is going into the engine, so it gets the "gallons" data from there (after initially calibrating from the tank measurement, probably when it's stable). It would make a lot more sense than trying to read the amount of fuel in the tank, which is very hard to do as it sloshes back and forth.

But this is just a guess. I wish we could talk to the engineers and ask them stuff like this!

 

Driving through the city I have been getting ~16mpg - keeping revs under 4k RPM.

 

Good point, but that may not necessarily be the case. For example, the analog gauge has a built in delay in most cars. It doens't just moveup immediately; I have driven off from filling up and the guage is still on the 1/2 mark moving up gradually.

A analyg to digital conversion can be applied to this guage; I say this because I recently talk to a friend of mine who claims there is high demand for analog-to-digital conversion engineers and one of the examples he gave was that the gas tank. We are in a digital world, but yet have to live up to accepting analog only measurements of many physical things. So much, it will probably become a science in itself. One day, the spedo will be accurate to the milimeeter by perhaps having a laser pointed down from the undercarriage measuring movement hundreds of times per second; until then though, we have to resort to an analog estimated speedo as well (my GPS discovered there was a 3mph difference in my current car @ 55 -- car was going 52).