LOW MPG ON '08 2.5 ALTIMA HELP !

[aznxrudy]

I just calculated my MPG and it came up to 13.5. I really doubt that this is the average MPG for my 2008 Nissan Altima 2.5S. Is there something I can do to improve my MPG.

Every time i pressed on the gas , my RPM only goes 2-2.5.
I rarely hard brake. I usually let the car slow down on his own.
I drive in New York City, whereas I drove around 20 highway miles out of 103 total miles. I drove around 80 city miles.
My trip usually takes about 20-30 minutes and since i drive in the city alot, i do have some decent amount of traffic lights.
My tire pressure is around 35 PSI.
There is usually only me in the car. I weigh 140 pounds and there are sometimes when I get a full car, but none of them weigh heavy at all. I dont fit more than 5 people in the car including me.
I had this car for about 2 years and I haven't got a wheel alignment once. *Leaning towards this problem*
I only replaced two of the four tires in my car, but i did rotate my back and front tires once before.
No mountains , mostly flat surface of where i drive.
I usually drive around 40 (rarely 50) on city and 60 (rarely 70) on highway
I have a Weapon-R SRI (said it gives me a bit of MPG, so i decided to throw that in there)
I do oil change every 3000 miles and i get the SYNTHETIC OIL
My spark plugs are new, put less than 200 miles on them.

I don't know if im missing anything, lmk but yeah. Can anyone figure out what could be wrong or any tips on what I should do to improve my MPG.

[sstroudwku]

The inner city driving has likely caused a carbon build up inside the upper intake, I'd suggest and upper induction and throttle body cleaning. Inner city driving is really hard on gas mileage, stop-go driving is the killer for it. I'd have the dealership turn off the CVT brake as well. With the SRI installed after your upper induction and throttle body have someone perform an idle air volume learn, your vehicle could be buring more fuel at idle due to the ecu programmed for a stock restricted intake. You should rotate your tires every 7500 miles, especially on the altima. I would be willing to bet you're alignment is out of spec as well. You can change to LRR tires "low rolling resistance" which will help a little as well.

Why did you change plugs? How many miles are on your car? Have you ever had the CVT serviced?

[elgringo]

I've noticed the same on my mileage when I drive in NYC. I'll visit home from time to time and notice on I-95, my fuel comsumption will go for days. Stopping every 30 seconds I find myself at a pump 2x a week depending on how/where I go.

I have a Takeda SRI installed and had no idea about having the intake system diagnosed. I figured bolt on parts wouldn't need any type of tuning; however, it does make sense that the air sensor is calibrated for a air box, not intake so the increase of air flow might cause some carbon buildup as mentioned.

I'll put this on my to-do list for sure.