Xterra 2012

Discussion in 'Nissan' started by Inst, Dec 14, 2014.

  1. Inst

    Inst New Member

    I'm having difficulty hypermiling an Xterra 2012. I can't seem to get much above the EPA ratings. IIRC, it should be 16 MPG city, 22 MPG highway.

    My reported MPG should be between 18-19 MPG city and 23-24 MPG highway.

    Terrain:

    Suburban, around a mid-sized city. Large roads are marked 45 MPH, some roads are marked 50 MPH, interstates are 70 MPH. Residential is marked 35 MPH.

    Techniques used:

    -Drive on half torque peak, because when looking at similar engines to what I have (I can't find the BSFC map for it), peak fuel efficiency usually occurs at half torque peak for gasoline engines.
    -Pulse and coast; I hover between 5 mpg of either speed limit -2.5 or the speed limit itself.
    -Timing traffic lights. If the light in front of me is red, I immediately take my pedal off the gas, and depending on the stop light distance, I either cut 20 mpg immediately off speed, wait a little, or hope that by the time I reach the back of the vehicle in front the light will have changed.
    -Usually speed limit speed driving. On a 70 MPH highway, I will usually do 70 MPH on cruise control, because pulse and coast on 5 mpg for hours is usually too tiring.
    -Turning off the engine at stop lights. I turn off the engine, switch to neutral, and get ready to restart and bump-start the car.
    -Wheel inflation. I try to keep the inflation up at about 110% of manufacturer specifications. It should be 45 PSI (iirc), it's set to 50 PSI.
    -Coast to stop. If I have a stop sign in front of me, or I need to drop to 0 speed, I just coast the vehicle on automatic drive, then brake sharply as I approach the stop.

    Techniques tried, then abandoned:

    -Driving on 2500 RPM or even 3000 RPM. The theory is that at higher throttle, the car should have greater fuel efficiency, but observing gas station receipts I don't get much out of it. Perhaps I'm wrong?
    -Pulse and coast in neutral. Illegal, probably damages the engine and wears out the ignition switch. Not doing it anymore.

    Stuff I won't try:

    -Drafting. Sounds cool, not putting up with the danger.
    -Car mods. This isn't my car, I'm not going to bother taking off the roof track to reduce aerodynamic drag.

    My problem:

    As you can see, I'm getting between 15% and 5% improvements on MPG compared to EPA fuel economy estimates. As someone who intends to hypermile, what am I doing wrong?

    For instance, should I do 10 mile pulse and coast? IIRC, it's annoying as hell to the driver behind me, although I can't honestly say that I am a good driver.
     
    Last edited: Dec 14, 2014
  2. CPLTECH

    CPLTECH Well-Known Member

    I have a 2006 Pathfinder, a slightly longer vehicle but same motor. Not completely sure if you have a 6sp manual, but the PF only comes with auto. Sounds as if you have the ScanGauge2. Here are my observations:

    Find the “LTFT” [Long Term Fuel Trim]. With a warm engine, in idle, the lower the number the less ethanol or else they dump better additives for better MPG performance. I find Exxon/Mobil best so if price is similar to others in your area, consider that brand. Winter blends take a toll on MPG.

    Use cruise control a lot. In today’s cars, cruise will maximize MPG vs. your foot [Heard it’s that drive-by-wire thing]. ScanGauge2 shows that shoving the trans in neutral at a light will lower idle consumption by ~10%. The auto trans does not “clunk” when put in drive at most any speed, so consider coasting down some grades where it makes it worthwhile. I don’t shut my motor off. I’ve heard on other PF forums that MPG’s are not too bad if you keep this engine around 2K max. Try to drive under the 60MPH range as much as possible. One time I put the cruise at 48 on a 4 lane country state hwy for some 80 miles. Got 27MPG. Otherwise 21 on trips. My tires are at 45-50PSI. Consider tires that have better rolling resistance. Avoid wider tires than required.

    Nissan put a longer stroke in the former 3.5L engine to make the 4.0L. Reason : Customers complained they wanted more power. It certainly has the power, but the PF in 2013 went to the 3.5 engine, as have other brands. CVT in the new PF is not without problems. Other brands are using 6 & 8 sp auto. If you have a 6sp manual, I envy you.

    Problem is this design is like pushing a square box down the hwy. The only option is to slow down.

    Hope this helps…
     

Share This Page