Hello,

I was wondering why my nissan maxima 2002 started wasting gas. Before it was a GAS SAVER! hardly wasted gas but now it wastes gas all of a sudden. Replaced the spark plugs with new ones and the ones it should be which is double platinum NGK. What could possibly be the problem? I do use unleaded gas. would premium make a difference?

 

What's your REAL MPG?

Please be specific waste gas is not specific.

 

Agreed with Nmex - we need a ton more info that what the OP is giving us in order to help.

 

Yea idont know too much about cars. I just looked up online how to find the mpg and the TRIP button on the wheel is a bit confusing. but anyway i drive about 20 miles a day n it will kill the half of a half tank. I can't really explain well. so please help me out.

 

^
a faulty fuel injector can cause lower mileage

http://www.carsdirect.com/car-buying...ad-gas-mileage

 

ok...so all you do is reset the trip odometer to 0 when you fill it up. drive for a week or whatever, then when you fill it up again, take the MILES DRIVEN and divide that my the number of GALLONS you just put in the tank.

 

That is too complicated. I makes my head hurt...

 

push the little black button in front of the steering wheel.

 

Same here I did the math on it before and was avg about 26-28 on a good day. Last few trips have been horrible, I took a trip yesterday and i avg like 14. Same driving mostly high way. Still no clue what it is. Waiting for gas filter to come in for replacement. Thats all I can think of.

How often do fuel injectors go bad, anyway of knowing if it is bad or not?

 

Do you have a engine check light on? Since there's a lot of factors that can contribute to gas mileage, such as tune up, air filter, O2 sensor, if engine check light on. Missing gas cap, bad cat converter, again engine checklight.

 

Wassup guys. So I'm not sure if the mpg button is working. Well I dont know how to use it. So I went to put gas because it was almost empty and it ended up going to 3/4. So I press hold TRIP button and a dash comes up moving to the right and back again. At first it didn't work and on the second try it did and it was working well. After putting gas, I took it to the highway. The number was increasing until it reach 22 then it stopped for a while and then it started dropping down to 13 mpg. Is that normal? I haven't put gas yet. Now it doesn't move and sometimes moves up or down by one number.

Mpg started dropping when I got off the highway.

 

Not sure if serious.


At risk.....

You are following the car's calculated mpg, which is wrong 99.9 percent of the time. It's a good "dummy indicator" though.

You need to read the trip meter. Every car has one. Push and release the small black rod on you gauges until it gives a a number and the letter "A." Then press and hold it until the number displayed clears to zero. That is your trip meter.

Now, follow instructions outlined above to measure your fuel economy between fill ups.

Anytime the engine is running you consume fuel. If you let the car warm up before driving (I recently had a cold snap for several days) that will drop the mileage you get from a tank. Among other issues and maintenance problems that may or may not exist.

 

Ok so im not going to use the steering wheel button instead i will use the one on the gauge. Iwould try that when I refill gas again! I did change the air filter and got to manage to fix the p4800 code which is some valve. So it didnt have check engine light on at all since last week until it appear last night. Havent got a chance to look at it. I was thinking of replacing the fuel pump but I'm not sure if that could make a difference.