Hey guys, I am due for an oil change, so I checked the readings and it was pitch black covering maybe 1-2 inches of the rod, I know this is not good at all. Can this contribute to poor MPG? I mean im getting 200 miles on a tank with 70% city driving. Please help. THANKS

 

So...change your oil!

Is it overfilled? Did you check it after you ran the engine? Usually, you have to let a Maxima sit for a while before any oil reading can be considered an accurate one.

 

i don't think its overfilled. All I want to know is if its possible for the terrible gas milage being due to the fact that i was needing an oil change badly? Because I'm getting one today, and am sick and tired of filling a $30 tank a week.

 

I've noticed on mine that as my oil gets low, gas mileage goes down.. not saying this is a hard and true fact, but i've noticed it.. never as bad mileage as you.. but worse than normal..

 

i wouldnt say its helping

 

did you clean the dipstick off and then check it again? The car engine has be be cold also

 

How about changing the oil, and re-checking gas mileage? Then you can tell us if it made a difference.

 

You should change to synthetic, I heard that it increases your mileage too. I use it, but can't say that it did anything to the mileage. I only use it because it supposedly protects the engine better and thats what its all about right?

 

How many miles do you have on it?
When was the last time you serviced it (spark plugs, fuel filter, air filter)?

Also I cleaned my IACV and ever since then I went from 320-330 miles per tank to 370-385 (that sucker was really dirty when I pulled it off). I plan on using seafoam in my system to see if it will clean out the rest of the gunk in it and bump my mpg up.

 

damn, i get the same amount of miles as you were getting, 320-330, is there a how to clean the IACV? I have no idea what that is

 

Yeah, I agree, sounds like it's time for a cleaning, servicing, tune-up. Oil shouldn't have that much of an impact on fuel performance.

 

what this IACV and how do i clean it, my cars 9 years old, it probalby needs a cleaning, any writeups or is it in the haynes manual? im getting 20 mpg no matter what i do

 

I need to clean that valve too...IACV. There have been a few posts about it, but I cannot use the search function. I'm going to check the Haynes manual tonight. My gas mileage has been pretty bad as well. I used to get around 370-400 a tank (without the light coming on), but now I am only getting 340 at most to a tank.

However, I also moved from San Antonio to Dover, DE, so that might have an influence as well...colder weather.

 

Well i got my tune up today. Oil changed everything checked and was fine. Air filter was DISGUSTINGLY DIRTY so that was changed too. I got 3/4 tank left so well c if i can get more than my usual and pathetic 200/tank.

 

And the guys that did the oil change, took this experiment tube and showed me that once they mixed thier solution with a sample of my oil it didnt turn pink like it was suppot to. They told me i need a full tranny clean and bs thats costing bout 150$ i told them no thanks and left so I can know whats the deal on that from my buddies here at the ORG. THANKS

 

I can't remember the post where I got this from but here is the info:

The credit goes to Mango95SE for this procedure.

Tools needed:
10 and 12 mm sockets
3 inch socket extension
universal joint (swivel pivot socket thing)
12-inch rachet (a short rachet may not work - need something to apply a lot of torque to loosen the bolts
Philip's screwdriver
rag
throttle body cleaner

1. Unplug the 4 connectors from the IAC assembly. Undo the hose that connects teh IAC to the intake assembly.

2. The metal bracket holding up the gray-colored connector is blocking one of the IAC mounting bolts. Using a 10mm socket, remove the bolt that holds the metal bracket. The bolt is just below the purple connector - you have to twist your head and crane your neck around to see the bolt.

3. Remove the 3 mounting bolts using the 12mm socket. The lowest bolt may require the Universal joint.

4. Pull out your IAC valve and clean it w/throttle body cleaner, rag, and old toothbrush.

You may even want to separate the plastic valve to clean it more thoroughly. Use a philip's head screwdriver, but make sure it is a snug fight. It's on there tight and if you don't have a good fitting screwdriver, you could ruin the screw head.

Reinstallation is just the reverse of these steps. It may be easier access to the IAC if you remove the whole air intake assembly, but it's not necessary.



I did this because my CEL was tripped with a 0803 code for the boost sensor. This link suggested cleaning the IACV
http://forums.maxima.org/showthread....highlight=0302

but Mango95SE did a great job with the write up. I saw an improvement with my gas mileage with no real change in driving habits. Hope it helps.

 

My Maxima definitely gives worse mileage when the oil is done. I got this twice, one for trying to use Castrol Syntec up to 7k and the second one was due to Auto-Rx (went to 2000 miles instead of 1000).

Guess what, once I went above 5500 for the Syntec, my mpg drops from 29mpg highway to 24. The second time this happened was last month, I thought the Auto-Rx needed to be changed at 2000. I was wrong since it was supposed to be changed after 1000 miles. In this case, when I went above 1500, the mpg drops to 23 highway.

A lot of people think that the condition of oil do not affect mpg, but in my case it certainly do. Even when I change my filter (synthetic) and put a little bit of oil to top it off, it really pushes the mpg a bit (to 30mpg).

Hopefully this helps!

 

bump bump bump

 

I don't see how engine oil has any significant effect on gas mileage. I guess you could argue that with improper lubrication there is more friction on the pistons, but I sincerely doubt this claim.