235 miles from a full tank. Please help

[THT]

Take your car to Autozone or Advance Auto Parts and have them hook up an OBDII scanner. You may have a knock sensor problem and it will not trip the CEL/SES light (ghost code). Your KS may be fine though as you have relatively few miles on the car. Change out your fuel filter too.

~THT

[Ceasars Chariot]

your dang right about that

[torvan]

Originally Posted by vinceleto

Torvan:

I don'nt want to sound like a jerk but I have a few questions.

How big is your tank?

Do you get 450 miles mostly highway and all the way empty, I mean with the light on and everything?

I know spark plugs can make a difference but 450 miles city-highway sounds a bit much or my 2000 sucks way to much gas. I recently got 350 miles to 14.5 gallons thats about 24 MPG from honest city-highway driving. I also have a bike rack on my roof which may cause a little drag but can't be that big of a deal. If you got 450 miles on 15 gallons thats
30 miles per gallon if you were bone dry maybe you used 16 gallons thats 28 MPG. What do you get on highway driving 600 miles? just kidding hahaha. Let me know if you have done anything else to get such good milage.

I run the tank until the light comes on, then a little while longer, depending on how far the station is. Usually, I have to get about 16.5 gallons of gasoline or so to get what station attendents call "Full" (Self serve is illegal in Oregon).

My tank is an 18.5 gallon tank, and the 450 figure I gave you is both city/highway mixed, since I live in a suburb and drive to another city on a moderatly heavy traffic freeway. When I drive on the highway only with no city traffic, I get about 480 or so based on my last trip from Dallas (OR) to Boise. (496.7 miles each way). I usually have to fill just across the Idaho border if I am full when leaving Dallas. Given that at the time I bought the car, it was rated for 21/28 mpg, I am not finding my mileage all that surprising--I am getting damn near that, and I have 109K on the car.

I get that mileage by driving the posted speed limits for the most part, keeping my tires at the right pressure, keeping it tuned and running at specs and since I live in Oregon-I rarely need the AC. I do not have any racks or anything on the car, and the load is just myself and the other half most of the time, which adds just 400 lbs to the car weight. I am a pretty calm driver for the most part, so drag racing that pissass Honda that wants to race me is not something I entertain. Now, getting ahead of that semi before my lane ends-that I do. And if I get pissed off from all those crappy drivers on I-5 between Salem and Portland--then my mileage suffers when I gun and throttle between cars at 70-95 mph---but that is a rare event.

My car is a 1999 Maxima SE with 109,765 miles.

[THT]

Torvan, you're not alone. After modifying my Max and doing routine maintenance, I'm getting 27mpg, mixed city and highway driving (60/40). This last time I filled up, I drove 385 miles on 13.8 gallons for a total of about 28mpg. I very rarely floor it though; last time was to check to see if my DR mod was working and that was about a week ago. I drive conservatively with OD on and rarely let my car stretch her legs. Highway driving is done with the cruise control set at 70mph. With gas prices the way they are, there's no way I'll waste a drop of my liquid gold.

~THT

[vinceleto]

Torvan:

Thanks for replying. I drive a 2000 maybe it uses a bit more gas although the est milage is the same. I do get 28-29 MPG on long highway only trips but I drive mostly city and some highway. That's probably my problem, I was just wondering if I could get better MPG than I'm getting.

[torvan]

You're welcome-anytime I can help I am always happy to do so!