WHY do I get 12MPG?????
11-25-2008, 10:22 PM
#81
Senior Member
iTrader: (7)
Join Date: Dec 2004
Location: Alexandria, VA, & Central Jersey
Posts: 2,647
if i run the oil a LOT past its due, then it gives me REALLY bad gas mileage. Don't know why. I run fully synthetic and change around 6k-7k. My car knows very well when i run it past 7k.
11-25-2008, 10:42 PM
#82
They do have the OBDI Consult in the fusebox if im not mistaken.
http://forums.maxima.org/avatars/pmo...ine=1202198098
http://forums.maxima.org/avatars/pmo...ine=1202198098
11-28-2008, 02:55 AM
#84
11-29-2008, 01:00 AM
#87
11-29-2008, 04:37 PM
#88
but it all goes in my never break 15mpg an my old commute. Though my subie did a little better.
11-29-2008, 11:20 PM
#89
Senior Member
Join Date: Apr 2008
Posts: 165
i got the 07 s4 maxima lovers im sorry but that thing is a streight up beast. I i rape 95% of the cars that try to race me. (only got beat by a few vettes) but AY maxima is still my fav notthing beats the simplicity. changing an air filter took me almost 2 hours on the damn s4.
11-29-2008, 11:53 PM
#91
Newbie - Just Registered
Join Date: Nov 2008
Location: Northwest
Posts: 1
Poor mpg indicators.
I didn't read all the prior responses, but i would recommend checking on your o2 sensor to ensure that they are creating the proper voltage from heat exchange. Generally, this would give you an error code if they failed or went out of range, but not always. The o2 issues would also give you secondary indicator problems...such as poor excelleration, hesitation at times and possibly rpm surging during normal driving.
Also, check to see if your running ethenal/gasoline at your local gas station - this will generally cause you to lose approx. 10 - 15% mpg.
Here in the northwest, they run this additive 1/2 the year at most gas stations. (Generally during the winter months). Major decrease in mileage is always noticed.
Also, check to see if your running ethenal/gasoline at your local gas station - this will generally cause you to lose approx. 10 - 15% mpg.
Here in the northwest, they run this additive 1/2 the year at most gas stations. (Generally during the winter months). Major decrease in mileage is always noticed.
11-30-2008, 01:37 PM
#94
11-30-2008, 02:53 PM
#95
He wasnt trying to kill the o2 sensor cause all he would have to do is just stare at it and the o2 would have jumped off the vehicle and flung itself into on going traffic.
11-30-2008, 03:01 PM
#96
I've had horrible CITY gas mileage on my I30 for the past couple months and performance started to drop. Then I started get lean error codes and I couldn't find anything blatantly wrong even using my Datascan software.
It had me completely stumped until Friday--now it's fixed.
Since I bought this car in April I've replaced a bunch of stuff and the mpg and performance was great until recently. So far I've replaced both O2 sensors, plugs, injectors, fuel filter, added KN Air filter, replaced MAF & TPS, replaced bad crank sensor and Knock sensor, tested every other sensor. I've cleaned the EGR port and throttle body. Took the intake plenum off and made sure it was true and installed a new gasket. Replace the thermostat. Located and cleaned ALL ground connections. New ATF and oil. Tire pressure runs about 35PSI and I have NO brake drag. NONE of this was related to my recent drop in city mpg.
So, how did I fix my problem?
Took off the EGR valve and related parts and cleaned the crap out of the valve. Then put it back on WITH gaskets (there weren't any when I took it off) and replaced all of the hoses that had anything to do with EGR.
While I had the plenum off I noticed the valves and valve guides in cylinder #1 had some carbon buildup compared to the rest (probably a previous leaking injector) so I cleaned all of that out too.
My I30 now pulls ahead with that thrust my head back in the seat power we all know the Maxima/I30 can deliver. City gas mileage jumped from 14 to 18 and I'm not driving easy--it's way too much fun to drive like I'm in a race!
Hope this helps someone. It has been ticking me off for a long time now!
It had me completely stumped until Friday--now it's fixed.
Since I bought this car in April I've replaced a bunch of stuff and the mpg and performance was great until recently. So far I've replaced both O2 sensors, plugs, injectors, fuel filter, added KN Air filter, replaced MAF & TPS, replaced bad crank sensor and Knock sensor, tested every other sensor. I've cleaned the EGR port and throttle body. Took the intake plenum off and made sure it was true and installed a new gasket. Replace the thermostat. Located and cleaned ALL ground connections. New ATF and oil. Tire pressure runs about 35PSI and I have NO brake drag. NONE of this was related to my recent drop in city mpg.
So, how did I fix my problem?
Took off the EGR valve and related parts and cleaned the crap out of the valve. Then put it back on WITH gaskets (there weren't any when I took it off) and replaced all of the hoses that had anything to do with EGR.
While I had the plenum off I noticed the valves and valve guides in cylinder #1 had some carbon buildup compared to the rest (probably a previous leaking injector) so I cleaned all of that out too.
My I30 now pulls ahead with that thrust my head back in the seat power we all know the Maxima/I30 can deliver. City gas mileage jumped from 14 to 18 and I'm not driving easy--it's way too much fun to drive like I'm in a race!
Hope this helps someone. It has been ticking me off for a long time now!
11-30-2008, 03:59 PM
#97
Senior Member
Join Date: Jul 2008
Posts: 127
well im gettin about 255 miles to a tank filled up tuesday from a quater to F and now after thanksGiving im almost at E and 255miles later which only took me to fill up was 11 gallons thats like 23.18 miles to the gallon i guess it sucks but still is better than 12, but what do u guys think about getting 23.18 miles to the gallon?
11-30-2008, 05:43 PM
#98
well im gettin about 255 miles to a tank filled up tuesday from a quater to F and now after thanksGiving im almost at E and 255miles later which only took me to fill up was 11 gallons thats like 23.18 miles to the gallon i guess it sucks but still is better than 12, but what do u guys think about getting 23.18 miles to the gallon?
11-30-2008, 06:56 PM
#99
Newbie - Just Registered
Join Date: Sep 2007
Posts: 7
i'm having roughly the same problem. i'm getting pretty bad mileage. I also can smell gas when stopped in traffic and when i park my car. I've noticed some dampness on two of the vacuum lines going to my evap vent control valve. Am i correct in assuming that this valve is the cause of my problems? I also have a PO440 code (small evap leak).
11-30-2008, 07:37 PM
#100
i'm having roughly the same problem. i'm getting pretty bad mileage. I also can smell gas when stopped in traffic and when i park my car. I've noticed some dampness on two of the vacuum lines going to my evap vent control valve. Am i correct in assuming that this valve is the cause of my problems? I also have a PO440 code (small evap leak).
Fix the code, fix the mpg...
11-30-2008, 10:05 PM
#101
you guys said a lot for a day.
There are some things that sound useful, but I don't think I'll go all out to fix that much stuff.
maximomo - thanks for the information! I am still not brave enough to take the IM off and do all that work. Everything else that you have done I have as well. I need to change both of the valve cover gaskets and the IM one too. I think after new year's with the tax refund I will take it to a shop and have them do all that. I know it will cost me money but..... I am not brave enough for this kind of job.
how hard is it anyway? can someone give some info on the subject or may be a link?
There are some things that sound useful, but I don't think I'll go all out to fix that much stuff.
maximomo - thanks for the information! I am still not brave enough to take the IM off and do all that work. Everything else that you have done I have as well. I need to change both of the valve cover gaskets and the IM one too. I think after new year's with the tax refund I will take it to a shop and have them do all that. I know it will cost me money but..... I am not brave enough for this kind of job.
how hard is it anyway? can someone give some info on the subject or may be a link?
12-02-2008, 08:30 PM
#102
a little update on the MPG
this week I filled up and have gone about 85 miles in-town-only driving and according to the gauge I have only used 1/4 tank. that means I can get over 320 miles to the tank.
320/18= about 17mpg which is MUCH better than before. since its winter and with my short trips I think that would be plenty. The way I achieved that is staying off the gas pedal
this week I filled up and have gone about 85 miles in-town-only driving and according to the gauge I have only used 1/4 tank. that means I can get over 320 miles to the tank.
320/18= about 17mpg which is MUCH better than before. since its winter and with my short trips I think that would be plenty. The way I achieved that is staying off the gas pedal
12-02-2008, 08:37 PM
#103
a little update on the MPG
this week I filled up and have gone about 85 miles in-town-only driving and according to the gauge I have only used 1/4 tank. that means I can get over 320 miles to the tank.
320/18= about 17mpg which is MUCH better than before. since its winter and with my short trips I think that would be plenty. The way I achieved that is staying off the gas pedal
this week I filled up and have gone about 85 miles in-town-only driving and according to the gauge I have only used 1/4 tank. that means I can get over 320 miles to the tank.
320/18= about 17mpg which is MUCH better than before. since its winter and with my short trips I think that would be plenty. The way I achieved that is staying off the gas pedal
Not to mention, assuming that because you got 85 miles for approximately (and probably nowhere near) a 1/4 tank, that you can get 255 more miles out of the tank?
12-02-2008, 10:41 PM
#104
I guess you are right. What I was trying to say was that for the last month or so, since I've had the bad mpg I was going like 90 miles a week and that was about half a tank of gas. so now I am 100% sure my mpg is better since I am at 85 miles and definatly not at half a tank
12-03-2008, 06:44 AM
#106
Senior Member
iTrader: (7)
Join Date: Dec 2004
Location: Alexandria, VA, & Central Jersey
Posts: 2,647
indeed.....i remember i had to hunt down the last gas station that didn't switch over to ethynol yet. But now, they're everywhere!!!! imo..i think that BP has the highest percentage of enthynol in their gas....i burn through that crap like its water running through a hose...
12-03-2008, 07:23 AM
#107
Member who somehow became The President of The SE-L Club
iTrader: (19)
Join Date: Jun 2001
Posts: 16,033
You guys do not know how to correctly calculate MPG. Reading your gas gauge is not the way to do it.
You need to fill up, reset the trip ODO and drive until your almost empty. Then fill up again, watch the gas pump and make sure you record the gallons the pump puts into your tank. Now take the miles on your trip ODO and divide it by the gallons used.
That is the only way to calculate your MPG. Watching your gas gauge is the IDIOT way to do it and is grossly(sp?) inaccurate.
You need to fill up, reset the trip ODO and drive until your almost empty. Then fill up again, watch the gas pump and make sure you record the gallons the pump puts into your tank. Now take the miles on your trip ODO and divide it by the gallons used.
That is the only way to calculate your MPG. Watching your gas gauge is the IDIOT way to do it and is grossly(sp?) inaccurate.
12-03-2008, 08:14 AM
#108
Member
Join Date: Aug 2008
Posts: 81
You guys do not know how to correctly calculate MPG. Reading your gas gauge is not the way to do it.
You need to fill up, reset the trip ODO and drive until your almost empty. Then fill up again, watch the gas pump and make sure you record the gallons the pump puts into your tank. Now take the miles on your trip ODO and divide it by the gallons used.
That is the only way to calculate your MPG. Watching your gas gauge is the IDIOT way to do it and is grossly(sp?) inaccurate.
You need to fill up, reset the trip ODO and drive until your almost empty. Then fill up again, watch the gas pump and make sure you record the gallons the pump puts into your tank. Now take the miles on your trip ODO and divide it by the gallons used.
That is the only way to calculate your MPG. Watching your gas gauge is the IDIOT way to do it and is grossly(sp?) inaccurate.
12-03-2008, 08:15 AM
#109
You guys do not know how to correctly calculate MPG. Reading your gas gauge is not the way to do it.
You need to fill up, reset the trip ODO and drive until your almost empty. Then fill up again, watch the gas pump and make sure you record the gallons the pump puts into your tank. Now take the miles on your trip ODO and divide it by the gallons used.
That is the only way to calculate your MPG. Watching your gas gauge is the IDIOT way to do it and is grossly(sp?) inaccurate.
You need to fill up, reset the trip ODO and drive until your almost empty. Then fill up again, watch the gas pump and make sure you record the gallons the pump puts into your tank. Now take the miles on your trip ODO and divide it by the gallons used.
That is the only way to calculate your MPG. Watching your gas gauge is the IDIOT way to do it and is grossly(sp?) inaccurate.
I know very well how to do the math.
what I was talking about with the gauge is that even though its VERY incorrect, it still shows the level in general. so last week after 85-90 miles my tank was about half way down. this week 85 miles is at the 1/4 line. so according to this ROUGH ESTIMATE I am getting better mpg. and when I fill up next time I will do the math as I already know and as you have explained.
01-04-2009, 07:10 PM
#111
01-05-2009, 06:23 AM
#113
My Maxima delivered in August 1994 is probably the very first 95 model. It is compatible with ODBII, though the scanner port is on the passenger side (not the driver side as the later models).
01-06-2009, 01:37 PM
#118
my last fill up showed about 14mpg. that is horrible! I talked to a friend the other day and now I am considering taking the Max to a shop with my tax return money. I am thinking of an injector cleaning service done and that. And if I have to I will pay for diagnostics at the dealer.
01-06-2009, 03:13 PM
#119
Junior Member
Join Date: Feb 2004
Posts: 17
That's a good idea. I've always found working on peoples cars if everything seems in order but you get bad mpg, clean your injectors & change the filter.
also everyone should own a scanner if they do work on there car. Not to rad codes but to look at data scream and stuff like that. The good autozone scanners will allow you to look at most of the sensors in the car while the car is running to see if they are operating correctly. Your base timing might be off killing mpg. You can also look at short/long fuel trims to see how the car is doing. You can check to see if the car is switching between open/closed loop..........
also everyone should own a scanner if they do work on there car. Not to rad codes but to look at data scream and stuff like that. The good autozone scanners will allow you to look at most of the sensors in the car while the car is running to see if they are operating correctly. Your base timing might be off killing mpg. You can also look at short/long fuel trims to see how the car is doing. You can check to see if the car is switching between open/closed loop..........
01-06-2009, 08:32 PM
#120
i usually get really good gas mileage but then i got really crappy gas which had alot of water or something in it cause my car ran like crap and has had trouble starting at times for the past week. i put some fuel line cleaner and octane booster in to compensate for all the other crap in the gas and now ive driven 130 miles and im at 1/2 a tank. i dont think ive ever used this much gas before. I always regtet saving the 7 cents per gallon.