gas mileage
12-01-2009, 08:05 PM
#1
Junior Member
Thread Starter
Join Date: Apr 2007
Posts: 21
gas mileage
alright...a little perplexed about this one...
i recently purchased my wife an 03' GLE to match my 02' SE...love having his and hers maximas...same color and everything, she got the leather...
anyway, we took my wife's 03 traveling this past weekend and i tested the road mileage to compare with my 02. i was blown away to see it only got 20-21 mpg on the highway...
My 02 gets 28-30 mpg highway, (which I am very happy with obviously), and i am trying to figure out what may cause the 03 to be worse.
A few thoughts...
1) My 02 is a 6 speed, hers is an auto...anything related to gear ratios? i also noticed that when i cruise at 80mph in my 02 the tac sets around 2.5, but hers sets right at 3. My dad wondered if its shifting into overdrive and I believe that it is, it shifts 3 times from a stand still so I am assuming the auto has 4 gears, may be wrong on that and that may be the issue..
2) My 02 has less mileage, 82k, hers has 120k and probably needs a tune up, but would plugs/wires/etc make that big of difference?
3) I use 93 in both vehicles...any chance a previous owner not using 93 would cause a problem? i noticed a difference in mileage when i used 87 instead of 93 in my 02, but again, dont have enough info to know long term effects.
I am pretty puzzled by this...same motor, same size car, almost 10mpg difference on the highway...you all have any suggestions? appreciate it!
i recently purchased my wife an 03' GLE to match my 02' SE...love having his and hers maximas...same color and everything, she got the leather...
anyway, we took my wife's 03 traveling this past weekend and i tested the road mileage to compare with my 02. i was blown away to see it only got 20-21 mpg on the highway...
My 02 gets 28-30 mpg highway, (which I am very happy with obviously), and i am trying to figure out what may cause the 03 to be worse.A few thoughts...
1) My 02 is a 6 speed, hers is an auto...anything related to gear ratios? i also noticed that when i cruise at 80mph in my 02 the tac sets around 2.5, but hers sets right at 3. My dad wondered if its shifting into overdrive and I believe that it is, it shifts 3 times from a stand still so I am assuming the auto has 4 gears, may be wrong on that and that may be the issue..
2) My 02 has less mileage, 82k, hers has 120k and probably needs a tune up, but would plugs/wires/etc make that big of difference?
3) I use 93 in both vehicles...any chance a previous owner not using 93 would cause a problem? i noticed a difference in mileage when i used 87 instead of 93 in my 02, but again, dont have enough info to know long term effects.
I am pretty puzzled by this...same motor, same size car, almost 10mpg difference on the highway...you all have any suggestions? appreciate it!
12-01-2009, 08:29 PM
#2
Lol yes its a 4 speed auto. It will always be at higher rpms when compared to the 6 speed, it has longer gear ratios. Thats part of the reason why the gas mileage is decreased. You're also traveling at 80 mph, your gas mileage gets steadily decreased the faster than 55 mph you go. Slow it down, get a quick tune up, and come back with the results.
12-01-2009, 08:52 PM
#5
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Join Date: Jul 2009
Location: Covington, GA
Posts: 63
I have to agree with the tune-up possibility. I have an '02 6 spd with 150k miles on her. I average only 24mpg. I drive a mix of city/highway and keep speeds around 70 on the interstate. My dash gage used to show me 29 mpg before my maf went out but calculator only showed 26-27. Since the maf replacement with an '01 model from DaveB it now shows an average of 25.5 mpg that I compare every fill up with a calculator and come up with 24. It's nice to see the gage is fairly accurate. Mine could use a tune up as well and will hopefully get one after the new year. On a side note, my mom drives an '02 Altima 3.5se auto and gets 32 mpg confirmed.
12-01-2009, 08:52 PM
#6
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Join Date: Sep 2006
Location: berkeley, ca
Posts: 107
i get at least 28-29mpg at around 80mph on cruise control on the trip from SF to LA consistantly(about 400mi). But that has been nullified by cruising at over 100mph, with spurts of 130-150mph, early morning hours between 1am-5am on the interstate on more than one occasion
expect 20mpg, if your lucky, but imho, amazing still. the 4speed does have taller gear, to make up for the disparity, but you should be getting significantly better milage, even with the 4speed. doesn't have electronic overdrive?
expect 20mpg, if your lucky, but imho, amazing still. the 4speed does have taller gear, to make up for the disparity, but you should be getting significantly better milage, even with the 4speed. doesn't have electronic overdrive?
12-01-2009, 08:57 PM
#7
At 120k it is past time for the plugs to be changed (by the way there are no wires) as the Maxima has coil packs. Speed has great deal to do with it as well as proper tire pressure (should be 32 psi all around) and your manual will most likely always out perform the auto (this coming from one that has an auto 03 SE). Once the maintenance issues are dealt with it will come down to driving practices that will get you the better gas mileage
12-01-2009, 09:09 PM
#8
Yea I would say there is some cause for concern because I consistently get around 26-27 mpg on the highway, and I drive it like its stolen
Do you have any codes? I would look into running seafoam through it, deffinatley change the air filter, and if you can, swap in some new plugs. Goodluck
12-02-2009, 01:09 AM
#10
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Join Date: Apr 2009
Location: Tucson, AZ
Posts: 388
a] a33 maximas have 4 speed automatics. lucky 6 speeders drive at lower RPMs on the highway so they get better gas mileage. This is pretty much common logic.
b] the highway mileage is rated at 24mpg.
c] you are WAY overdue for a tuneup. Its about $200 at your local nissan dealer. Change those plugs. There are no wires. Yes spark plugs make a difference.
d] try changing air filter.
e] yes you need at least 91 octane gas to get the best mileage. anything lower causes the engine to retard the timing, reduce your hp, and reduce the mileage.
d] overdrive is the 4th gear. 1-2-3 then OD which is your fourth gear. Make sure the torque converter is engaging too. I average 2900 rpm at 80mph.
b] the highway mileage is rated at 24mpg.
c] you are WAY overdue for a tuneup. Its about $200 at your local nissan dealer. Change those plugs. There are no wires. Yes spark plugs make a difference.
d] try changing air filter.
e] yes you need at least 91 octane gas to get the best mileage. anything lower causes the engine to retard the timing, reduce your hp, and reduce the mileage.
d] overdrive is the 4th gear. 1-2-3 then OD which is your fourth gear. Make sure the torque converter is engaging too. I average 2900 rpm at 80mph.
12-02-2009, 06:46 AM
#11
You would think a more aggressive driving behavior with the 6MT would result in a completely opposite mileage experience. But my guess is your SE has been well-maintained, and this GLE is a wild-card. Do the basic tune-up options mentioned here (plugs, air-filter, clean the MAF, seafoam), and make sure the tire pressure is spot-on.
Why are you running 93 octane? Unless you're trying to address pinging, the engine is designed for 91 octane, Andy. Money out the window.
And who cruises at 80 mph? That's pretty funny.
Otherwise... 2 Maximas in the garage. That's cool.
Why are you running 93 octane? Unless you're trying to address pinging, the engine is designed for 91 octane, Andy. Money out the window.
And who cruises at 80 mph? That's pretty funny.
Otherwise... 2 Maximas in the garage. That's cool.
Last edited by Rochester; 12-02-2009 at 06:49 AM.
12-02-2009, 07:44 AM
#12
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Location: North Shore, MA
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I do.
yeah.....pretty cool. But the matching his and hers is pretty
12-02-2009, 08:04 AM
#13
As to the "matching his and hers"... I'm thinking it's more like both cars are really his, but his wife drives one of them.
Boy, we're OT now.
12-02-2009, 08:50 AM
#14
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To get back on topic OP, do a tune up like everyone here said and report back with the results.
12-02-2009, 12:17 PM
#15
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Location: Sacramento
Posts: 383
12-02-2009, 12:24 PM
#16
Later on, I tried somewhat less "extreme" behavior, bordering on the normal; (i.e., keeping revs under 4000), and I got 30 mpg.
Normally, I get 25 mpg... because driving for mileage is a decidedly joyless way to own a Maxima.
12-02-2009, 01:07 PM
#17
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Join Date: Apr 2009
Location: Tucson, AZ
Posts: 388
91 octane isn't ubiquitous? See, now, I didn't know that. Most stations around here have it, so I just assumed. Um, my bad. Thanks for the info.
As to the "matching his and hers"... I'm thinking it's more like both cars are really his, but his wife drives one of them.
Boy, we're OT now.
As to the "matching his and hers"... I'm thinking it's more like both cars are really his, but his wife drives one of them.
Boy, we're OT now.
12-02-2009, 07:52 PM
#19
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Join Date: Oct 2009
Location: Atlanta
Posts: 1,222
Compare apples to apples. MT and Auto is a big difference for starters.
Point is how to get the mileage up. Tune up. MAF. Driving habit. Fuel rating. Load, as in weight, sometime people forget they have junk in the back.
All about weight and power needs.
Point is how to get the mileage up. Tune up. MAF. Driving habit. Fuel rating. Load, as in weight, sometime people forget they have junk in the back.
All about weight and power needs.
12-02-2009, 10:19 PM
#21
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Join Date: Apr 2009
Location: Tucson, AZ
Posts: 388
Take into account that the difference between 87 octane gas and 91+ octane gas is at most 40 cents. For a full tank fill, that's a mere $4 more per fill up. If you can't dish that out, then you should really consider changing vehicles.
12-03-2009, 06:51 AM
#22
Something is definitely wrong. The automatics are rated at 26 mpg freeway and that is what mine gets with a cruising speed in the low 70s when I drive between Dallas and northern Kentucky. Trip computer says 29-31 mpg freeway but we all know how inaccurate it is. My best tank on the freeway was 27.4
I'd check the air pressure in the tires, air filter, plugs, etc. You should be getting about 5-6 mpg better than you got.
I'd check the air pressure in the tires, air filter, plugs, etc. You should be getting about 5-6 mpg better than you got.
12-03-2009, 11:57 AM
#24
My 2002 GLE (4AT), according to the trip computer gets anywhere from 31mpg-34mpg highway. I've never changed the spark plugs (been meaning to, though) and it's got 51xxx miles. I use 93 octane fuel with an injen CAI, tire pressures set at 35psi for a little boost in mpg. Definitely check all regular maintenance items and keep an eye on tire pressure! Tire pressure can easily make or break fuel economy. On my summer tires I ran them at 45psi F/R and it got excellent highway and around town mileage (the tires max psi was 51, so it wasn't overinflated past limits). Cheapest thing to do is check your tire pressures, then follow up on the maintenance.
12-03-2009, 12:11 PM
#25
My 2002 GLE (4AT), according to the trip computer gets anywhere from 31mpg-34mpg highway. I've never changed the spark plugs (been meaning to, though) and it's got 51xxx miles. I use 93 octane fuel with an injen CAI, tire pressures set at 35psi for a little boost in mpg. Definitely check all regular maintenance items and keep an eye on tire pressure! Tire pressure can easily make or break fuel economy. On my summer tires I ran them at 45psi F/R and it got excellent highway and around town mileage (the tires max psi was 51, so it wasn't overinflated past limits). Cheapest thing to do is check your tire pressures, then follow up on the maintenance.
The trip computer is horribly in accurate with it come to mpg, common knowledge here atleast. Wow running your tires at 45psi, just wow.
12-03-2009, 12:22 PM
#26
Yikes!Obviously, you're comfortable with this, or you wouldn't be doing it. And certainly your rolling resistance will be reduced, increasing MPG... but, still, road grip goes out the window. And safety, too.
I think you should research tire pressure some more before continuing that practice next summer. Seems pretty scary to me.
12-03-2009, 05:13 PM
#28
12-03-2009, 05:33 PM
#29
Member
Join Date: May 2009
Posts: 41
run several tanks before you decide your mileage
re; octane,, i have a 99, 01, 07 and i run 87 until very hot weather and i have not any problems, i would never run 93 unless im racing. 93 doesnt burn completely in my opinion under normal driving. I have monitored the timing under different octane conditions and that is why i run 87 most of the time.
the 07 ave combined driving is 25.5 mpg on 87 octane,,,long term ave.
re; octane,, i have a 99, 01, 07 and i run 87 until very hot weather and i have not any problems, i would never run 93 unless im racing. 93 doesnt burn completely in my opinion under normal driving. I have monitored the timing under different octane conditions and that is why i run 87 most of the time.
the 07 ave combined driving is 25.5 mpg on 87 octane,,,long term ave.
Last edited by cobradb; 12-03-2009 at 05:36 PM.
12-03-2009, 07:38 PM
#31
12-03-2009, 08:01 PM
#32
Yikes!Obviously, you're comfortable with this, or you wouldn't be doing it. And certainly your rolling resistance will be reduced, increasing MPG... but, still, road grip goes out the window. And safety, too.
I think you should research tire pressure some more before continuing that practice next summer. Seems pretty scary to me.
12-03-2009, 10:44 PM
#33
Senior Member
Join Date: Oct 2001
Posts: 866
My driver's rear sticks a little. Until I get to replace the cable (I verified that's the problem), I just reach behind the tire, and pull the parking brake lever on the caliper towards the rear of the car. Makes a big difference.
12-04-2009, 05:44 AM
#34
Haha I know, they're really high. But, the tire is rated differently so when I actually run the tire at a lower pressure mpg goes down substantially, and believe it or not the tire doesn't grip as well (feels as if it's rolling over). Yeah, it seems high, but the tires wore great (not just in the center like you'd expect with an "overinflated" tire. The tires gripped well even at those pressures, but I took those tires off for the winter and sold them because I don't think extreme summer tires are going to get ANY traction in the winter...which is why I got the pirelli's...which aren't snow tires by any means, but when your dealer goes out of business and you need tires...free is free my friends. Also that's why they're set at 35psi currently, just a little over spec but not enough to create a safety/performance issue, just to help decrease rolling resistance.
However, I base that opinion on nothing what-so-ever.
12-04-2009, 12:04 PM
#36
If you're really really into fuel economy, try visiting http://www.hypermiling.com/ or http://www.msnbc.msn.com/id/20706595/
Some of the techniques are a bit extreme, but if you're concerned about getting insane mpg's you could always go the extreme route.
12-04-2009, 12:04 PM
#37
12-04-2009, 03:53 PM
#38
I have a 2003 SE Auto. I did all the bs: seafoam, new filter, new plugs, 93 octane, tire pressure 36 psi, blah, blah, blah, blah, blah. I drive usually 70-80 mph. I never get more than 21 mpg on pure highway driving, In the city, I usually get 18-19 mpg. WTF???
...And my computer usually says I 'm getting 23-24 mpg.
...And my computer usually says I 'm getting 23-24 mpg.
Last edited by aroy3719; 12-04-2009 at 03:55 PM.
12-05-2009, 10:46 AM
#40
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Join Date: Sep 2006
Location: Mukwonago,Wi
Posts: 135
Cleaned Maf didn't do anything was getting 21 mpg on hwy according to the trip, so i figured Maf was fine...took a trip up north 600mi. got about 22 mpg for the whole trip...long story short Maf **** the bed up north...replaced the Maf with the 2k1 with the resistor swap...cost 90 bucks vs. the 2k2 Maf with the resistor cost 400 bucks. On the way back the trip gauge read 32.2 mpg on the way back, and felt like a brand new car.
i have a 2002 with 6 speed and always run 93 octane. Also dynoed the car @ Maxus '09 235 whp....dynoed car after i changed the maf just for kicks 269 whp both dynojet dynos...fuggen MAF! I had given up on finding the mpg problem, and i checked everything and changed everything i thought i needed to thinking it would solve the problem....plugs, coilpacks, Cleaned UIM, Seafoam, Checked back brakes for sticking, Fuel treatments, had injectors checked, compression....and i had no codes or no pending codes...thank god the MAF just completely crapped out, i dealt with those ****ty MPG #'s for 2 years.
After doing the Tune up if that doesn't solve the problem, maybe try swapping your Maf from your '02 into your wifes '03 (since you have another max handy) and see if you notice a difference. I do believe they are interchangeable since they both have the resistor in the Maf it shouldn't matter that one is Auto and the other is Manual
i have a 2002 with 6 speed and always run 93 octane. Also dynoed the car @ Maxus '09 235 whp....dynoed car after i changed the maf just for kicks 269 whp both dynojet dynos...fuggen MAF! I had given up on finding the mpg problem, and i checked everything and changed everything i thought i needed to thinking it would solve the problem....plugs, coilpacks, Cleaned UIM, Seafoam, Checked back brakes for sticking, Fuel treatments, had injectors checked, compression....and i had no codes or no pending codes...thank god the MAF just completely crapped out, i dealt with those ****ty MPG #'s for 2 years.
After doing the Tune up if that doesn't solve the problem, maybe try swapping your Maf from your '02 into your wifes '03 (since you have another max handy) and see if you notice a difference. I do believe they are interchangeable since they both have the resistor in the Maf it shouldn't matter that one is Auto and the other is Manual
Last edited by Staticxout2; 12-05-2009 at 10:50 AM.