gas mileage

[cellysel]

How can I get better gas mileage on my 01 pathfinder ? It has 174,000 and Its getting around 14mpg average. I changed the spark plugs, air filter, front wheel bearings. Along with a front end alignment and wheel balance. I also changed the rear shocks and trailing arms because of the death sway but that has nothing to do the gas mileage but thought I'd just you know.

[patqx4]

Manual hubs (if 4wd)
Weight reduction

Those 2 things will yeild you the most gain.

[cellysel]

It's a two wheel drive with a 3.5 with ngk platinums

[cellysel]

What type of weight reduction,

[mthatch]

Just a few things that go a long way.. and you may have checked most of these already.

Tyres and wheels - (rolling resistance) balance issues and inflation, rubbing, siping pattern on tyres
Fuel - (restriction)fuel filter and injectors
Brakes and Rotors - (rolling resistance) brake ride on rotors, stuck caliper piston, stuck caliper slide pins, bent rotor shield, warped rotors, brake shoes riding drum, emergency brake left on (it's possible)
Bearings - (rolling resistance) front inner and outer bearings, rear bearings, centre support bearing on drive shaft/propeller shaft if 4x4,
Oils and fluids- (mechanical resistance and heat) motor oil level and grade, transmission level and grade, differential level and grade, transfer case level and grade, coolant problems, low coolant
Sensors - (intake and exhaust) MAF sensor, O2 sensor
Vacuum - (leaks) throttle plate to intake valve, vacuum controlled units
Transmission - (mechanical resistance) manual - clutch problems - auto - torque converter slip
Exhaust - (leaks and restrictions) muffler, catalytic converter, rust, holes
Engine - (mechanical resistance) drive pulley on alternator and power steering pump, fan hub and fan, idler pulley assembly for acc and primary, ac compressor pulley and clutch.

I know that this is a lot of stuff to check, but if this is your daily driver or you have a single vehicle, its worth a check. Also, make certain you are using premium grade fuel (91 octane). If you're not, do a quick search and you'll find a write up about it.

As for weight reductions, try removing the spare tyre. That's all I can think of. You could use light weight rotors, calipers, and wheels, but that all cost money. Smaller and narrower tyres help.

[04pathse]

Do you do mostly city driving? if you do, you are right about where you should be, the vehicle is rated at 16 mpg city / 19 hwy but in reality 14 or 15 (city) is about the best you are going to get, but you could try changing the fuel filter and maybe some fuel system cleaner, it might help a little....

[Buzzman]

These things are pigs on gas. No way around it.
I've had mine since 2003, and the biggest mileage gain that I have control over is through my driving habits.
Quick starts and acceleration from a stop, and high cruising speeds on the highway are the two major factors for me.
When I lighten my right foot, I get better mileage. Dropping below 70MPH on the highway makes a big difference.
Not drag racing from a stop also helps.
Lastly, as someone above mentioned: lighten the load as much as possible.

[atraudes]

I'm surprised no one's mentioned the roof rack yet. Removing it and the rear wind deflector/spoiler will reduce drag a bit.

Buzzman hit the nail on the head, though. Mine is running like a top and I still only get 14 to 15, which isn't bad, considering. I have 4WD, haven't reduced weight or drag, run A/T tires, and am not particularly delicate with the throttle. When I first bought it I was getting closer to 11 or 12, but maintenance like mthatch was talking about really turned that around.

Even if it's not throwing codes, issues like a rough idle, smoke, hard starts, or vacuum leaks could be indirectly affecting fuel economy too. Track them down and take care of them.

[cellysel]

I'm using the cheap 87 octane , so I know that's not helping, and I have a ski rack. I drive 20 miles to work with no traffic and 20 miles back home stuck in traffic on the freeway. I'll run errands around town usually on the weekend's. I have AT tires , oh yeah and I do have a lead foot . My pathfinder runs great, with it being summer right now I usually have the AC on. Actually last week I was able to average 16 mpg . So it's getting a little better. What kills my gas milage the most I think, is the windy summer days. That wind takes a toll with the pathfinder being so high.

[prognxt]

Just wanted to add to this thread.

On open highways, 65mph for 350 miles, I can pull 20mpg.

When I'm working for a week, and fill up on the weekend, I get normally 18-19mpg.

I normally use 87 octane, and my vehicle is stock on all season tires inflated to 32PSI.

I dont particularly have a heavy foot. I like a smooth ride, and my RPMs rarely goes above 4.5k

[rgk]

Replacing the very worn spark plugs on my ride improved by mileage from 10-14 to 17-20.

I also replaced the PCV valve, but I'm not sure whether that had anything to do with it. The improvement was most noticeable after replacing the plugs.

In retrospect, I was dumping a lot of unburned fuel through the system - I could smell it, but mistakenly thought the smell was coming from a small EVAP leak, which I still have.

[donald]

Just wanted to add my thoughts.

When I first got my 2001 QX4 I made some initial "measurements" prior to installing what I thought would assist in MPGs
BTW, I purchased my Qx4 used in 2011 with about 156k-miles on it. Previous owner bought it 2nd hand from his friend. Assuming he was telling the truth:
Owner1: father purchased for high school daughter. When daugther graduated and went to college, sold the truck to 2nd owner, the person I bought it from
Owner2: father (a school principal - if that might give any insight to his reputation) bought it for his son who JUST got into college, who played baseball.

My general driving is 80% highway, 20% city or stop-n-go traffic. Stop-n-go traffic usually involves the driving it takes to get from house to the highway :P

I compared 3tanks of 87 and 3tanks of 91 - result was little to no difference. I was getting between 17-18mpgs, similar numbers on both octane grades. Although I will admit that I fill up with 91 when I am going on a worthy distance road trip.

Then I installed my Warn manual hubs. I didn't do another fuel test, but did let the ride settle with 3tanks before measuring again.
Similar to before I installed the manual hubs, I did not see any significant improvements in MPG, still ranged low-17s.
Even today, whether hubs are locked or unlocked, I don't see any significant changes in MPG. I will still get 17s with them locked.

Since then, I've done the following (not particularly to improve MPGs, but rather to show that little can be done when it comes to parts and MPGs)
New front disc brakes (pads and discs)
New suspension (OME medium duty springs and KYB struts/shocks all around)
New tires "All Season" tires - ie. not knobby tires :P. The tires claim "low rolling resistance"
Also did the trailing arms (upper and lower) to poly bushings
Using Amsoil synthetic ATF
Walmart brand synthetic motor oil

I keep a pretty empty truck. I don't have a sound system/subwoofer/amp in my truck (not implying that you do:P). Since I do drive a lot of highway/non-stop speeds, that may be a major contributor to my MPGs and the non-effect of the manual hubs and fuel grade.

Just address your driving styles first prior to dumping more money into the truck for things you may not need. For example - I really didn't need manual hubs ($100), but I threw them in because I liked to look cool :P (admission to being a poser! haha).

[rgk]

Air conditioning plays a big part too, as does 2wd/4wd usage.