1996 Nissan Hardbody Pickup

Discussion in '4x4's, SUV's and P/U Trucks' started by melinuxfool, May 28, 2009.

  1. melinuxfool

    melinuxfool Well-Known Member

    The best I've gotten for mileage with my 1996 Nissan was 26.5 MPG. The old epa ratings said 20 mpg highway, I believe. The problem is, now that the U.S. mandates 10% ethanol in all the gas, I'm finding it difficult to even achieve 20 mpg. I didn't think that 10% ethanol could reduce my FE by over 23% (that just doesn't make sense mathematically), so I put a new set of plugs in, changed the fuel filter and PCV filter (in the air-box with the air filter, which was brand new already), yet it still didn't seem to want to get over 20 mpg. In fact, my last tank averaged 19.8 mpg, horrible for a four-cylinder with a five-speed manual. (I never used to get under 22, even if I used the 4x4)

    Anyone else have any tips for this vehicle? I have a cap on the back, it is light weight (I can lift it on myself), made of aluminum. Still, the thing is like a brick on wheels, not so aerodynamic. I live in Maine, I don't know how many are familiar with the terrain, but it's mostly hills, and steep ones.

    Overall, I'm a little peeved at the government for putting this moonshine in the gasoline (a scheme to raise gas tax revenues without actually raising the tax maybe?).
     
  2. Kinder

    Kinder Well-Known Member

    Obviously circumventing ethanol is easier said than done, so... What kinds of speeds are you driving? I had a 91 Pathfinder V6 4x4 with the auto tranny for a while.. Driving 55-60 on long highway trips could pull 20 or 21mpg. That was also with all roof racks removed and tires at max sidewall, so if this hasn't already been done, you should do it--low hanging fruit and easily worth a couple of mpg. Also this was on NV trips, so on long, straight mountain descents I would coast in neutral--you have the option to FAS. And DWL helped my Nissan quite a bit, I think (without a scangauge option the feedback info is pretty limited). Good luck and keep us posted! I have had my eye on some rigs similar to yours, but I can't live with sub-20mpg, so I'm very interested to see how your hypermiling affects things.
     
  3. melinuxfool

    melinuxfool Well-Known Member

    I was wondering about the safety effects of pumping up the tires to max sidewall. The recommended cold pressure is 26 psi (per manufacturer), whereas the max sidewall pressure is almost double what is recommended (50 psi). I currently have them at 36 psi, and the ride is not noticeably rougher (the thing rides like a buckboard regardless).

    It has manual hubs that I keep set in the "free" position.

    I'm not much of a speed demon in my truck, since I don't like pushing it hard. Highest speed limit in Maine is 65. In 5th gear, that's about 3,000 RPM (per Scangauge, the truck itself doesn't have a tachometer). 55 is about 2,500 RPM and 45 is 2,100 RPM in 5th gear. I generally go from 1st to 2nd at 10 mph, 2nd to 3rd at 20, 3rd to 4th at 30, and 4th to 5th at 40, shifting at between 2000 and 2,300 RPM, and rarely above 3000 RPM, because I don't push it hard, even going up hill. Since I don't drive on the interstate much, my speeds usually top out at 55, unless coasting, which is when it goes as fast as gravity is willing to take it :)

    I'm not entirely sure I understand DWL yet. With automatic cars, I often ease up on the gas going up hills to try and prevent a downshift, is it a similar. There is an LOD gauge on the scangauge, does that have something to do with it?

    Also, this truck is fuel injected, does anyone know if it has the fuel cut-off when coasting in gear? I'm trying to figure out if it is better to coast in neutral or in gear. Though the thing has lots of compression, even in 5th gear at 40 mph, it won't gain speed unless it's a steep downhill grade.
     
  4. Taliesin

    Taliesin Well-Known Member

    I can't answer all your questions, but I might have some insight into these two issues.

    Tire pressure: The vehicle manufacturer states 26 psi for a smoother ride. However that low of a pressure stinks for FE (and tire wear). The tire manufacturer is the one that would have issues with safety and tests the tires to well over double the max sidewall rating. My Ranger has a Ford recommendation of 32, max sidewall of 44, and they are currently set at 54 with no issues at all.

    With those RPMs I would try like heck to find routes where I could stay below 45 mph. I have just recently managed to start shifting at 1800 RPMs instead of 2000+, and it is giving me no end of results (4th to 5th happens at about 38 mph). Also, any time I am in a steady cruise situation above 30 mph I am in 5th. On flat roads I can hold 35 mph in 5th at 55-60 mpg.
     
  5. ksstathead

    ksstathead Moderator

    Placard pressure does 2 things versus sidewall max that Nissan wants: Soft cushy ride (relatively), and shock absorption. No safety issue at sidewall max. Actually handling is better at max sidewall. You should be prepared to lower pressure if you will run at high speeds on very rough roads that might stress the other suspension components. Otherwise, it is the easiest way to improve mpg.

    It does not explain why your mpg's had decreased, so the mystery remains...

    fuel cut off should display as 9999 impg on sg II, if properly configured. If present, it requires a minimum rpm (downshift as needed) and at least a partially warm engine. See your SG instructions to set the fuel cut off parameter.
     
  6. Kinder

    Kinder Well-Known Member

    DWL-- when ascending hills, yes, keep the load on the engine steady. Don't downshift and don't vary your pressure on the accelerator pedal... just let the truck's speed dip and then gain back that speed in neutral on the way down the other side. Steady speeds on varying terrain is a mileage killer in any vehicle, but in heavier 4x4s with smaller engines in particular. Work with gravity!

    Not sure about the fuel cut-off--though I'd wager you do not have it--but even if you did, you're likely to get better results with a longer coast in neutral than a shorter coast in gear. Unless of course you will need to completely stop/slow down in short order for a light or lower speed limit or whatever. I use the fuel cut-off every time I drive, but I live downtown in a somewhat large city. On the highway, coasting in neutral--engine on or off--is much more valuable. That's great that your ride is SG compatible, I would have guessed not.

    And yeah, 50psi sounds about right, to echo others. Not a bad thing to slowly increase to that number as you adapt to the very minor effects--not bad effects, just a change--on handling.
     
  7. satchel

    satchel Well-Known Member

    I run 50# in the 31x10.5 15s on the 91 Pathfinder with no problems. Avoid ethanol like the plague it is. People eat dirt cookies and we subsidize the production of crap ethanol from a food crop.
     
  8. nervousmini

    nervousmini Well-Known Member

    Here is what I have been having success with in my Blazer:

    1. Tires at sidewall max psi.
    2. Driving at or slightly below posted speed limits.
    3. I have an auto trans, but I have been using moderate acceleration to about 2400 rpm to gain speed as quickly/efficiently as possible so I can get into 4th gear and TC lockup.
    4. DWL, works but I don't always have the opportunity to use it with urban traffic.
    5. Also put the truck on a weight/aero diet - seems to have helped a bit.
    6. Full tune-up and all fluids changed with royal purple synthetics.

    What kind of spark plugs did you replace with? I have seen allot of problems caused by incorrect plug choices.
     
  9. Trucks and 4X4's are harder to hypermile than a car IMO. All it takes is a brief lapse and you accelerate to hard and your MPG takes a huge hit.

    Be careful with high air pressures. In my Explorer I run 50 psi but 55 psi makes it very unstable in turns even at low speeds. I'm just not comfortable with pressures above 50 in that particular truck.
     
  10. melinuxfool

    melinuxfool Well-Known Member

    Well, I have to say, this week I've used less gas than ever. Since I've been laid off, I haven't driven anywhere. It's amazing how little gas a vehicle uses when it isn't in use. :D

    So DWL is basically maintaining a steady throttle vs a steady speed?

    As to ethanol, I've tried to avoid it, but every gas station in my area has the 10% moonshine blend. Try as I might, I cannot find a station without it. It's like an infestation.
     
  11. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    You got laid off?? :( :(

    I hope you can find something soon. This is a terrible market to be unemployed in. :(
     
  12. melinuxfool

    melinuxfool Well-Known Member

    Just temporarily. It happens a lot this time of year for the company.
     
  13. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    I certainly hope it is temporary.

    On a different topic, what distribution do you run?
     
  14. melinuxfool

    melinuxfool Well-Known Member

    Depends on my mood. :D

    I'm forever tooling around with various distributions just for fun. So far, I think Ubuntu is my favorite, but there are good strengths in the others as well.
     
  15. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    Cool. I try to keep updated on the various releases, but I'm a FreeBSD guy. ;)
     
  16. melinuxfool

    melinuxfool Well-Known Member

    Made a trip today to visit a relative that was up from Florida using some of the techniques I've learned here. First stop was to get some air to air up my tires to 50 psi (sidewall max). So about half the trip was made with tires at 35 psi, and it was windy today (20 to 30 miles per hour). 23 mpg was what I got total - According to the scan-gauge.

    One thing I noticed with having the tires inflated to the max, it seems like the motor doesn't complain as much if I shift really early (like 5th gear at 35 mph). I think the early shifting helps a lot with acceleration FE.

    Now if I could just master DWL... I tried it today, with the scangauge LOD gauge (and RPM gauge, since I don't have a tach), trying to maintain a steady LOD reading. Anyway... things are looking up for my truck. Perhaps with practice, I can hit 30 mpg. Now that would be awesome.
     
  17. Kinder

    Kinder Well-Known Member

    Great, keep us updated. How far was the trip, and have you found the scangauge to be pretty accurate?

    Some folks on the forum advocate driving in socks to get a better feel for precise modulation of the accelerator pedal; sounds like that might be of use with your close use of the LOD and throttle readings. I wear old running shoes most days, and those transmit enough pedal feel for me.
     
  18. Taliesin

    Taliesin Well-Known Member

    That's one thing I have a problem with. I really do wear combat boots every day, and I am so used to it that being barefoot while driving is just wierd.
     
  19. melinuxfool

    melinuxfool Well-Known Member

    The trip was just a little over 20 miles. The scangauge is pretty close as far as actual fuel consumption is concerned. Usually within 0.1 to 0.2 gallons, which could easily be the pump. I'll know better when I fill up next time (the tank average went up from 21 to 21.4). The point of the scangauge for me wasn't the accuracy, but the feedback of how my driving affects mileage. That alone keeps me above the EPA ratings.

    One thing I noticed, as the vehicle is a 4x4, locking in the hubs, even if I don't use the 4x4 wastes fuel. The truck came with manual hubs, and leaving them unlocked gets an extra 1 or 2 mpg. If you have a 4x4, you might want to consider switching the automatic hubs out for manual hubs. Allowing those front wheels to freewheel is good for FE.
     
  20. melinuxfool

    melinuxfool Well-Known Member

    Well, I just refueled the truck today. I had been 153 miles on 6.704 gallons, or 22.8 mpg. I wish I could find gas without ethanol in it, but I don't think it is anywhere to be found in Maine. The majority of the tank was before I had learned some new techniques here, so the techniques here really paid off, considering only about 40 miles of the tank were real hypermiling.
     

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