I bought a used automatic '02 Maxima and am getting on average 18 mpg in the city and 24 on the highway; about 2 mpg less than the dealer sticker and what my digital readout is displaying (sometimes 4 mpg less than the digital readout). Anybody else experiencing this problem? I don't know much about the history of the car. What problems could cause a decrease in gas mileage and what are some things to help correct the problem (i.e. spark plugs, fuel filter, etc.)?

 

eh, unfortunately, that's not far off. I have always gotten between 20 and 23 mpg, depending on city/highway/road trip/traffic jam...and I have the VQ30, which probably is a little more fuel efficient then your VQ35.

Digital fuel economy meters rarely work well - I think there are a number of threads on this around the org., so it's well-documented for maximas at leat.

All of the things you listed could be a culprit, but I really wouldn't expect a huge increase....also could be bad coils, dirty MAF or throttle body...a million things.

 

Probably obvious things to most but just in case you overlooked them:

1. Tire Pressure! Tire Pressure! Tire Pressure, make sure it's right!!!

2. New air filter is a cheap fix and can effect mpg alot

3. Not sure how the org-ers feel about fuel injection cleaner but I used it in my old Jeep and it did boost my mpg a bit so might wanna get some good techron stuff and try that.

 

also, BG44K is rumored to help out.
I used it and didn't notice much difference except the engine "seemed" a little smoother...but no change in fuel economy at all...

 

is it true you can only add it if you're car is less than 3 yrs old or 30k miles? Worth the money?