LandsEnd

19.5 lots of red lights, and stop and go driving.

bb700092

Assuming you have a 20 gal tank, you get 21 mpg from premium and 15 mpg from regular. While both the numbers seem plausible, I have never heard so much difference from using premium gas over regular. In fact there has been a lot of discussion both in this forum and elsewhere regarding the benefit of using premium over regular and no one has been able to conclusively prove any gain in mileage.

QwikKota

iTrader: (3)

When my light comes on at empty I can only fill up 15 gallons or so. There must be a huge reserve. 300 city driving is normal/possible but 420 is no freakin way. I agree with you, the sticker on the fuel door says use premium octane for maximum performance, not maximum fuel economy...

ROCKART

iTrader: (23)

us down there in the depths of the 4th gen forums have been goin at this for a while.

there is no way that premium gas is adding 6mpg.....
how long have you been doing the 89 vs 93 experiment? and over how many miles?

how hard did you try to keep the variables uniform ? weather? environment? driving styles? tire pressure? there is a lot to regulate.

http://forums.maxima.org/showthread.php?t=544688

this has some good info - began as a mixing octane thread and just turned into low vs high octane thread:

bb700092

Today I drove about 180 miles on two highways -- one with speed limit 70 mph and the other with 55 mph (actually a state route). I got an overall mileage of 27.9 mpg for the trip The highest mileage I could achieve at any point during the trip was 28.2 mpg. The trip was 90% highway and 10% city driving.

This is something I noticed. When I set the cruise at 70 mph, the mileage remained fixed at 27.3 mpg. When I set the cruise at 65 mph, the mileage fluctuated between 27.8 and 27.9 mpg. When I set it at 55 mph, mileage was a steady 27.9 mpg. I am not sure what factors might be playing a role in my observations, but I tend to believe that 65 mph is the maximum speed that can provide the best mileage in my max.

I am surprised that even though Nissan specifies 25 mpg hwy mileage for the 07-08 max, 28 mpg is achievable even with A/C running (2-3 bars).

STARR

iTrader: (1)

To bad there are no tuners out there that know how to create custom programming that can take full advantage of increased-octane fuel, I've seen Ford, GM and Dodge Trucks benefit from after market ECU add ons, going from regular to premium they have noticeable increases in performance.

As it is right now the manufactures are keeping the increased performance programming subtle so that owners don't inadvertently abuse their engines and cars.

NmexMAX

iTrader: (22)

Screw tuners, tune your own ride, add timing on your own (UTEC) and 'tune' at will. (for 91, 93, 98, 100, 110, etc. octane)

blackmax07

Alright I fillled up 6 gallons, and drove all city, and got 40miles and then got the low fuel reading..now thats some bs..do you think i should tell the dealer to check this out? i swear it says im getting like 12.3 now..

bb700092

Yeah, I think you should check with the dealer.

Before you filled up 6 gals, was it showing low fuel? If yes, then I don't think its a problem since there is some reserve. It seems Maxima has a big reserve because people (including me) have seen that 16 gals would fill up the entire tank while the specs say that the tank capacity is 20 gals. It might just be that out of your 6 gals, only 3-4 gals have been used and the rest is still in reserve.

Also, it is my speculation that the reserve is not fixed but variable. I think there is a fixed distance, say 50 miles, after which the tank will be empty if you are getting the current average mileage. So someone who is getting 25 mpg will see his low fuel come on when he has 2 gals in the reserve while a person who is getting 10 mpg will see the same when he has 5 gals in reserve. But again, this is my speculation and all the numbers above are made up for an example.

fcoral 05

i'm getting between 9and 11.5 mpg city drivingwhen i last calculated it i got 172 miles to a full tank all city driving which i think is a bit low compare to some other people. When i first got the car the computer was saying 17.9mpg avereage the battery went dead and ever since the most i was able to see was 14.2 mixed h/way and city. I think i may take it in to the dealer to have it checked. On a side note i'm sure we have a gas filter on our cars but where is it located?

RHMax

I rarely sit in stop and go traffic; but when I do, I see the needle moves as the car moves. I can see why some of you are getting really crappy MPG. Try taking your cars on the highway and see if the MPG improves. It could just be your normal driving conditions.

blackmax07

Just wondering, will they actually do something? Or is it just gonna be "well it depends on your driving habbits" and I hate the fact that we don't get loaners..wack.

RHMax

Try going on a highway for about 20 minutes and see if you can get in the low 20's. If not, there's something wrong.

hmr1979

30 on highway conservative 70 mph cruise. mixed driving in town is 23.1 - 23.4

Worst I have seen it is 19.7

I get better gas mileage with AC on, which still puzzles me, but whatever, works for me.

blackmax07

Highway is great, I get like 27..But yeah I'm defintly going to get this **** checked out.

ROCKART

iTrader: (23)

before knock sensor = 17-21 mpg

after knock sensor = 23-27 mpg

pilotguy18

04 SE 5speed manumatic with 20,000 about 30 HWY and so far 20 city

betep

Sold my 04 maxima and bought 04 acura tl last week(both 6spd) - still have subscrpttion to this thread.

In a city both cars ~17, BUT on the highway cruising @75mph The bes I could get aout of maxima is 26.5-27.
Acura got me 32mpg.

I figure its a poorly designed transmission - gear ratios to be more specific.
Acura runs@ 2500rpm, maxima @2750.
I know there is a displacement difference, but new 3.5TL has ~ same MPGs

I don't understand Y nissan made 6th gear so short, especially when VQ is a better low end engine then Vtec
That was 1 of the reasons I sold maxima


just my 2c

anm6

iTrader: (2)

21 MPG 04 SE.

tyman

75mph = 25.xmpg
70mph = 26-27mpg

But I've never gone a full tank of pure highway driving so I think doing 70 could get me 27.5-28.

2004 SL

bb700092

Good observation. Try 65mph and you might get close to 28mpg. Try 55mph and you might get up to 28.5mpg. I got 28.4mpg setting my cruise at 55mph for quite some time (1 hour or so).

zig8100

At 65 mph. I can get 31-32 mpg. 2004 se model 25000 miles. 5 speed auto. City driving i only get 16-19 mpg.

SilverMaxima06

http://spreadsheets.google.com/pub?k...SlkqUk4Ym4NmAg

This is what my MPG has been like. You'll notice the # of fillups late this summer and early this fall slowed down a bit. I was driving much less during that period because of I began to carpool and I was not driving.


Let me know what you guys think and if you have any questions.

I really hope this can answer most questions about MPG on this message board. I have a very wide range of driving terrain and conditions as well.

bb700092

Thats good book keeping. But I am surprised that you got mpg like 34.649 (#65) and 33.246 (#63) in all commute while only 23.668 (#64) and 24.845 (#37) in mostly highways. What do you mean by "all commute"?

SilverMaxima06

Yeah that was sort of my fault. I wasnt sure what kind of 'terrain' descriptions I wanted to use at the time until a bit later.

Pretty much, mostly highway means it included all my commute + extra city driving, thus being mostly highway but not completely mixed enough.

Also, weather and traffic played huge differences on some days but early on I didnt mention that in another 'notes' column like I should have.

My commute btw, is 70 miles one way and about 55-60 of those miles are "highway" driving.

bb700092

Did you ever try getting the mpg from the trip computer from pure highway driving i.e. driving at around 65 or 70mph continuously on cruise for 30 or 40 miles? Please let me know what you get because above 34mpg seems extraordinary to me. People get that kind of mpg with a hybrid Altima.

SilverMaxima06

Yes I did and it was indeed over 30.

However, the issue you have with calculation MPG anywhere anyday depends on so much.

Humidity, ambient temperature, gas pump operation accuarcy/etc... but i really do think my mpg was indeed that much that day.

I dont think I used heat or AC, i had little load in my car etc

i can 'repeat' that number too.

SilverMaxima06

lastly, the full version of my spreadsheet also includes what kind of oil i used, and tire pressure checks that i had made

tyman

Yeah, I live roughly 135miles from my parents house so I vary it up back and forth to see the changes. I would drive 65mph on the interstate but I would be passed by even semi's and I have a personal rule that no semi's pass me.

SilverMaxima06

Also I would like to add, my cruising speed during my commute works as follows:

Highway:
~23 miles avg between 70-75mph, with stretches of 80mph+ if i'm in a hurry or feel like driving fast
~15 miles avg between 60-70mph (speed limits change, lots of cops)
~22 miles avg between 70-80mph, similar to the first section

I get my best MPG in morning commute (less traffic, so less 'slowing down' and speeding up)

bb700092

Did you get the mpg's in the spreadsheet from your trip computer or did you calculate it yourself? If you calculated yourself, how did you do that?

SilverMaxima06

calculated myself, and used the trip computer too but trip computer i usually set for 3 months or so and i just let it average out for a long lnog time, rather than each fillup

the trip computer though has the average speed thing, which i like using, which is what i have above in the spreadsheet

to calculate mpg, its: miles traveled divided by gallons used

bb700092

Ok... In your spreadsheet, I get the miles travelled from the column "Distance Per Refill". How do you get the gallons used during these miles?

Sorry for being so pushy but I really want to know how someone can get above 34mpg in a maxima.

SilverMaxima06

not sure, and trust me i was quite suprised as well. i get the gallons every time i fillup... the numbers are there

step 1) fill tank, write down miles
step 2) drive, drive, drive
step 3) fill tank, write down miles and see how many gallons used

it's not really magic

bb700092

I think that is where some discrepancy creeps in. When you fill up tank, many factors come to play. For example, if you let the tank fill by itself by locking the gas pump handle, then after some time, it will unlock automatically giving an indication that the tank is full. At this point, if you still pump, it will accept some more gas. That shows the tank was not actually full. Try this for yourself any day.

Also, the amount of gas a tank can accept depends on the ambient temperature and how cold/hot your car is. So your calculations cannot be as accurate as the trip computer. Anyway, I get your calculations. Thanks.

SilverMaxima06

this isn't an exact science...

everything you said, everyone already knows... not sure what your point is...

however i fill my gas up the same way everytime.... and this is the ONLY WAY to calculate mpg manually... trust me, i know how a gas pump works and these are my results.... and if you read my posts, i already said some of the things you said. so it is what it is.

the trip computer also isnt very accurate all the time either....

SilverMaxima06

also, i have no idea what you're looking at but i have the ambient temperatures in my spreadsheet...... and i'm pretty sure my car is ually the same temperature as the ambient + whatever normal heat my engine gives.... and i'm pretty sure my tank shouldnt be getting too hot/cold that it should make that huge of a difference, and if it does, i'd start to get worried about nissan engnieering.....

SilverMaxima06

lastly, every car has the same kind of autoshut off feature... after all, how else would one know when to stop filling the tank? after it starts spilling all over your feet??

bb700092

My point simply is your calculations are not accurate. Above 34mpg is not possible on a 6th gen maxima. Try getting that mpg on a trip computer and you will know for yourself what my point is.

But of course, if you are happy with your calculations, you don't need to care what I say.

SilverMaxima06

as a matter of fact, i have gotten that on my trip computer
next time i'll take a picture of it just for you

i'll reset the trip comptuer AND take it on the higway and cruise around 70mph....