I read some where on the internet, that 2k-2k3 Maxima's usually get about 19 MPG. My question is which mods if any would help me to obtain a bit better gas mileage. For an example like an CIA, Exhaust, Chip, Spark Plugs, Ect.

Thanks, Derek

 

FYI...mods won't improve your gas mileage.

 

Try an air/fuel controller...i guess that can help lean out the gas where you don't need as much an improve gas milage.

 

Drive slower. I can get well beyond 500 miles on the highway and some city driving sanely.

 

What speed do you cruise at on the highway?

 

Only drive downhill? Or only with a tailwind?
Seriously, Maximas get reasonable mileage for a large car with a 3 (or 3.5) liter engine, but if you see a lot of heavy city traffic then even 19 mpg might be optimistic.

Slow down on the interstate. The engine power needed to overcome aerodynamic increases as the cube of the speed - the aerodynamic power at 80 mph is almost 2.4x that at 60. (That is not the only source of load on the engine, of course, and the others do not scale so dramatically. But over 45 or 50 mph in most cars, aerodynamic drag becomes the largest single load.) In city traffic, let the car coast as much as possible coming up to stoplights and stopsigns. (However, leave the engine in gear and the clutch engaged - the ECM has a fuel cutout that shuts off fuel to the engine when coasting, but if the engine is not driven by the momentum of the car, then it must consume fuel to keep idling.) Accelerate moderately - if you accelerate very slowly, the car will spend more time in the less-efficient lower gears, but WOT is also very inefficient. If you have a manual tranny, shift early, or if you have an automatic, leave it in "D" - they are usually programmed to shift early. Pay attention to maintenance items - especially, the engine air filter, and if the thermostat isn't letting the engine warm up, replace it. A cold engine is dramatically less efficient than a warm engine, so try to combine errands so that the engine sees as few cold starts as possible. To the extent your traffic patterns permit, avoid idling, especially when the engine is still cold.

Driving habits are definitely the biggest factor. Less significant things you can do are to minimize use of the air conditioner compressor (keep in mind if you have auto a/c that in the "auto" mode the compressor runs all the time at temperatures above around 25F) However, I've often read that at highway speeds, the added drag caused by opening the windows uses more fuel than running the a/c with the windows closed. Never tested it myself. Make sure the tires are inflated to the spec or even a few lbs more - also tends to improve the handling a bit, at the expense of a slightly harsher ride.

These are some suggestions... as the ad say, ymmv.

 

On average 65mph, though highways are weird here in Houston - ranges anywhere from 45 to 65.