HOW TO: Improve your MPG

Discussion in 'How To' started by VTNomad, Aug 5, 2006.

  1. jnaut

    jnaut Full Access Member

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    I have a question about speedo calc... If you go outside the OEM or OEM optional, can the dealer just put in your tire profile into the computer like he does with the OEM sizes, or do you have to do something special or custom?
     
  2. Ry' N Jen

    Ry' N Jen Banned

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    I, with the help of a GPS unit find that most often when cruising in and around the sixty five to seventy five miles per hour we attain the best fuel economy while on the freeway. City stop and go driving isn't much different then what the window sticker claims!
    So, we average around the 23 miles per gallon freeway. I think thats pretty good considering the size, weight, and roof rack. When the Thule ski box goes on the rack, the mileage does go down. Oh well!
    I'm 6' 5" 250 lbs. Also carry recovery gear, some food and water, my wheel chair. That equipment does add up.
    But considering that our Liberty Has 172 000 kilometer = 106 875.845 06 miles on it, I am content with it. Heck, my "green hell" Mini gets less mileage then the KJ! But it doesn't idle! :D.
    I only imagine how much miles per gallon we'll loose when the lift, tires, winch with Backbone mount, roof top lights, etc., etc.,etc.
    Who cares? We still pay around the ȼ0.94 per liter.
    The truck is awesome, comfortable, drives excellent, and is worth every penny!
    And at the end of the day, that's why we are all here on this First class forum!
     
  3. LibertyFever

    LibertyFever Full Access Member

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    Really all this discussion about improving your vehicle's MPG is common sense. There's no secret method or device.

    The best advice has already been given, drive gently like you have an egg (not a boiled one) under your foot when accelerate or brake. Basic maintenance and good housekeeping (no excess luggage) will insure you get the best MPG.

    My best milage was on a long trip at highway speeds; 22 MPG :D. My worst was while towing a 5000 lb trailer; 9 MPG (blarg)

    I agree that if you want something with good gas mileage don't buy a Jeep, by a Ford Focus.
     
  4. Redbone

    Redbone Full Access Member

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    Why is it that I read this thread and feel dumber???? That is REALLY bad because I REALLY can't afford to get ANY dumber.
    ________
    Uggs
     
    Last edited: Apr 30, 2011
  5. tjkj2002

    tjkj2002 Full Access Member

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    Don't feel bad,I have only 3 brain cells left and one went missing and the other 2 went on a search party(Alcy)
     
  6. Boiler

    Boiler New Member

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    I get considerably worse gas milage when I idle a lot or drive like a bat out of hell in town. I've tried to drive slow and careful and see a small improvement over driving like a maniac. I've gotten my best milage by accellerating moderately to get up to cruising speed as fast as possible but not going much over 3k rpm's in the process. I believe the key is getting into overdrive reasonably quickly, and staying there. 45 is just too slow in an automatic to stay in overdrive. My jeep wants to downshift so much that I need to definitely stay over 55, usually 65. Finally, interstate traffic on slightly hilly roads prove to be a PITA, as when it is just a little congested I have to brake regularly, killing the use of cruise control. On those hills I just cant maintain speed without downshifting unless cruise is on.

    Indiana driving is not a problem, the interstates are very flat. But even Ohio and its slightly rolling interstates cause me much pain and frequent downshifting. It's hard to maintain 75-80 on them unless I can maintain cruise control.
     
  7. HoosierJeeper

    HoosierJeeper Gold Supporter/Admin Staff Member Administrator

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    I had 2...3 went missing.....:eek:(Alcy)
     
  8. Kugellager

    Kugellager New Member

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    For me the only really noticeable mpg improvement came when I checked which settings of the air handling system that cause the AC compressor to come on and made the attempt try to keep it off.

    Keep the compressor from running (if it is not too hot or you can do w/o th AC) and you will see significant improvements.

    I went from 14.5-15.5 mpg to 16.0-17.0 mpg by just doing this.

    I have also created more air flow, pseudo ram-air and gone to a larger, smooth walled air tube to increase air flow with no noticeable mpg change. The perceived power and seat-of-the-pants acceleration feel definitely increased but no mileage gains for were seen on my Jeep from these mods.

    John
    ];')
     
    Last edited: Sep 29, 2009
  9. boebr1

    boebr1 Full Access Member

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    Okay, time for my two cents... I am a professional driver. I drive 18wheelers, have nearly 1 million miles on the books. I also used to deliver pizzas... around 2200 miles per month (did that for about 6 years), and I drive just to kill time when I am bored. Here is what little wisdom I can provide:

    Driving slow isn't the key... Driving smart and safe is. as in: try to work the stop lights (slow down gradually and try to still be rolling when they turn green).

    keep a minimum of a 3 -5 second following distance... as cars bunch up, someone will, without fail, slow down. the next tailgater has to slow more, the next one even more, it is a chain reaction until traffic comes to a stop (this is what causes most traffic jams). if you have sufficient following space, you can slow down gradually, and not have to stop before you can re-accelerate.

    These two suggestions can greatly decrease driving irritations... and will affect your mileage A LOT! If you have to stop a lot, you have to apply a lot of fuel to get moving again. This will also massively increase the life of your brakes. I had a girlfriend who would practicly run right up under the car ahead before jamming on the brakes. she got horrible mileage, and she needed to replace her brakes about once a year. I drive the way I am describing most of the time, a set of brakes will last me several years (i usually get rid of the vehicle before needing to replace them). These two suggestions will also decrease your chances of getting involved in an accident by a huge amount.

    Next... Oil... In less powerful cars, such as the 4cyl Geo Metro I drove while delivering pizzas... I discovered that using straight normal engine oil would get me the advertised mpg. I used a partial synthetic in the summer, this increased my mileage to about 35mpg on low grade fuel. In the winter I used full synthetic oil to keep my mileage around there, and make it much easier to start on the -30 to-40 mornings we were getting that particular year.

    Now, that's a gas!! :
    I found that using the cheapest fuel I could get, I would get about 35mpg(think it was around 35 for combined city/highway). on the middle grade, i would net another mpg. on the top grade fuel, i was running at 41-46 mpg, which off-set the cost of the more expensive fuel, and still saved me some money (remember I was driving a minimum of 2200 miles per month)
    All this being said, I have noticed that more powerful engines, and carburated engines from the 70's (mainly V-8s) don't notice enough differences in mpg to offset the costs of full synthetic oil (at 1 change per 2 to 3 months), or the high grade fuel.

    On the note of higher altitudes equalling lower power... what do you do when you have less power? you make up for it by either downshifting or flooring it... what does that do? increases your fuel consumption. So, you are going to lose both... negligible amounts either way with computer controlled electronic fuel injection... unless you plan on doing a lot of driving above 12,000ft elevation ( i don't suggest that, usually very cold, hard to breath for a lack of oxygen, and your carburated buddies won't be able to follow you).

    Next up... maintain your vehicle well. how is your alignment? how are your bearings and u-joints? (I like to replace all the grease with synthetic greases when it's time to service them). the extra drag from worn wheel bearings with little to no grease can affect handling and fuel economy by a lot... not too mention if you drive down I-15 into California in the summer with poorly maintained wheel bearings, you will create a new burned out mark on the side of the freeway where your wheel bearing grease finally burst into flames, then swallowed your vehicle in a ball of fire. worn or under-lubed u-joints and other bearings will lead to sure failure, but also cause drag, drag = less mpg. poor alignment causes drag, and worn out tires. (ever see a car going down the road with it's front tire bouncing like mad? it needs to get into a shop, it's not normal, and that affects performance and mileage if even only in the .01mpg range)

    Cornering hard is fun... but it causes more drag as well, slow a little before the corner, ride it through most of the way then start accelerating once you have reached the apex of the curve(most of the way through it), then start accelerating, the act of accelerating will get you back up to speed, but it also makes the vehicle go straight, so it helps you get out of the corner at a higher speed. this is all safer than braking in the corner, and gets you better economy than if you had to brake too hard and dropped more speed than you would have had to otherwise, causing you to need to accelerate harder).
    There are more things you can do, but these tips will make you a safer, more efficient driver, and you will be getting the best mileage you can.

    Oh, and I have run a GPS in my stock Renegade... my speedometer and odometer are both off. the speedo reads 4mph faster than actual, and the odometer reads more miles than actual (slightly). I figure once i get the lift, and I am running about a 31" tire, they will be about dead on for accuracy, thus alleviating the need to have the computer re calibrated and throwing it off again. So, the mpg figures i can do off of the odo, are actually better than what actual would be. bummer huh?
     
    Last edited: Sep 26, 2009
  10. boebr1

    boebr1 Full Access Member

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    holy sh*t!! I didn't mean to write a book, sorry guys and gals
     
  11. boebr1

    boebr1 Full Access Member

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    I should have also mentioned this, if you don't care too much about your tires, oveer inflate them, if your used to 32psi, go for 40psi, you will gain 1mpg there too, or, run separate set of tires and wheel for around town. little narrow pizza cutter tires at high psi will net you several mpg over larger, wider, mud tires at normal psi
     
  12. Diandra

    Diandra New Member

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    IDK about the rest of you, but I get over 20mpg.... :p
     
  13. Redbone

    Redbone Full Access Member

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    2wd or 4wd? hwy or mix? details pleeze.
    ________
    HURT FROM NEXIUM
     
    Last edited: Apr 30, 2011
  14. boebr1

    boebr1 Full Access Member

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    i run about 18-20 generally in city/hwy mix, and that is a lot of stop & go. noticed on the hwy it is better
     
  15. Redbone

    Redbone Full Access Member

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    I get about 17 mix. Drivetrain is all stock. I have Mobil 1 in engine but am a firm believer that oil cannot make a noticable difference in mpg. Being a shade tree engine builder helps me to understand just what is involved.
    ________
    Chevrolet Monte Carlo
     
    Last edited: Apr 30, 2011
  16. boebr1

    boebr1 Full Access Member

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    no shade tree involved, i actually have a degree in diesel repair. and all i did was give my real world experiences, involving an underpowered car. i haven't had a chance to try the synthetics in the jeep yet, probably won't make much difference since it has pretty decent power and 6 cyl. i just thought that since a lot of people have other daily driver cars, they might try for themselves and see what happens
     
  17. Redbone

    Redbone Full Access Member

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    Friction difference is the only reason there would be an mpg difference. If it were noticable wouldn't the less efficient oil allow the engine to fail within a very few miles?

    I've done extensive mpg testing on several engines and found no difference in mpg or performance on the drag strip. Our 9 sec Camaro don't like 50wt. is about the thing we ever noticed. Even that was questionable.
    ________
    Host And Design
     
    Last edited: Apr 30, 2011
  18. boebr1

    boebr1 Full Access Member

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    i think a 9second camaro probably has a little more power than a geo metro. i may be miss remembering my info, I know that i got a much faster start with the synthetic oils, maybe the mileage increase wasn't what I am remembering
     
  19. Redbone

    Redbone Full Access Member

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    None of my tests were done on anything smaller than 200 h.p. rated V8s. Smaller engines would be more likely to show the differences. I use the Camaro as an example because it was tested on dyno and track both of which can show very minor changes. My other tests were done using back to back to back fill ups where variations in driving conditions were considered. While less than scientific I had to conclude that there was no difference in m.p.g. Along with that conclusion I post some Redbone's theory on oil/engine wear relation.:)

    In the end we are both going by experiences and posting for the benefit of others. They can use the info as they please. What I have posted is not to tell you that you are wrong.
    ________
    Weed Vaporizer
     
    Last edited: Apr 30, 2011
  20. jnaut

    jnaut Full Access Member

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    Diandra, I too am in Seattle. See my mileage trend in my sig. Y axis is in increments of two, with zero at the very bottom.