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best speed for best MPG??

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Old Apr 1, 2005 | 09:40 PM
  #1  
oldschool's Avatar
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Default best speed for best MPG??

I have a 98 LX stock with an auto tranny. I ve read civics of this year should get 32-37 mpg, but the best i've got is 35.5 mpg.

I get 33 mpg if I drive 75-80 on the freeways and 34-35 mpg if I drive 70-75. does this seem like bad gas mileage or does someone have a recommendation on how to get 36-37 mpg??? It's not practical for me to drive 65 because the traffic will ride your *** all day, maybe you know what I mean.

I had an injector replaced recently and the fuel system cleaned by a Honda dealer. This immediately gave me 1 MPG more, but Im still not satisfied. Any recommendations????


T
 
Old Apr 1, 2005 | 10:03 PM
  #2  
kinosh's Avatar
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Default RE: best speed for best MPG??

I believe fuel efficiency drops about 10% when you speed up from 55 to 65 mph and another 10% going to 75 mph. Add another 5-10% if you use your A/C. Extreme cold weather and inadequate tire pressure will also decrease efficiency. You will probably get the best fuel efficiency at about 50 mph (when your transmission is running at the slowest rpm in the highest gear), although this is not something I've tried. Slow down to 65 mph and I'll bet you will reach that upper limit.
 
Old Apr 2, 2005 | 04:15 PM
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Default RE: best speed for best MPG??

Oldschool,
To increase MPG at real life highway speeds try increasing the height size of the stock tires, not the width.
I.E. if stock = 195x60x14 and at 75 MPH irpm is 3000, switching to 195x65x14 should lower RPM to 2800
at 75mph to increase MPG, yet be prepared to lose a little low end torque.
HXville
 
Old Apr 2, 2005 | 04:31 PM
  #4  
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Default RE: best speed for best MPG??

Air up your tires, replace your air filter and slow down.
 
Old Apr 3, 2005 | 12:52 AM
  #5  
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Default RE: best speed for best MPG??

gain a little speed when you are going downhill, then lose a little when you are going uphill. let the free speed you gain going down a hill to help coast you up the next hill. and add about 5 psi to your tire pressure. maybe a new set of spark plugs and wires, along with the distributor cap and rotor. dont go crazy on som exotic plugs, just get some bosch platinums (the single ones, not the +2s or +4s.) or NGK plats. the boschs were about 2 bucks when i bought some last week.
 
Old Apr 3, 2005 | 01:07 AM
  #6  
se7ensectoolate's Avatar
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Default RE: best speed for best MPG??

Hit teh clutch on the downhills. Seriously, I do when gas is $2.15 like it is here now.
 
Old Apr 4, 2005 | 11:20 AM
  #7  
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Default RE: best speed for best MPG??

gas is 2.81 for premium here. it's crazy. anyways, is there any difference between holding your clutch down while coasting vs putting it in neutral with the clutch up? is either way worse/better for the clutch/engine? I know it's illegal to coast neutral down a hill or anywhere for that matter, but everyone does it....
 
Old Apr 4, 2005 | 02:35 PM
  #8  
FG078's Avatar
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Default RE: best speed for best MPG??

I don't think holding the clutch down or putting the gear in neutral while going downhill will help you get more mpg. What you can do is just let go or barely hit the gas pedal when you are going downhill & stay in gear.

My current Civic, the 02 EX coupe is auto. It's my daily car. On the highway, I usually run about 70mph (3000RPM). I get about 26mpg on my car. I also drove my car in a lot of locals.
 
Old Apr 14, 2005 | 12:03 AM
  #9  
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Default RE: best speed for best MPG??

After three weeks of trying out different things I have been getting 36-38 MPG. I took your advice and added 2 psi over the recommended amount, which ended up at 32 front, 31 rear. I've continually gone to the same "good" gas station, instead of picking the stations that save me 50 cents a fillup. I'm still only using regular. I now drive 70 whenever possible; just have to leave 5 minutes sooner.

I'm satisfied with the results especially with reg costing $2.40.

thanks
 
Old Apr 14, 2005 | 12:20 AM
  #10  
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Default RE: best speed for best MPG??

Regular here only cost 2.06 but with Wal-Mart shopping card 2.03.
 
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