07-18-2014, 10:32 PM
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#1 (permalink)
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EcoModding Lurker
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Instant +11% fuel economy
So I was wondering why my truck seemed to be getting such crap MPGs. I then had my speedo die, and pulled the transmission speed sensor and found out I had the wrong gear. I had a 30 tooth gear, and my truck is supposed to have a 27 tooth gear for the speed sensor. Since I have been keeping track of my mileage and it was easy enough to correct for the error. My lifetime average is up to 25.3 MPG, up from 22.86. Not bad, eh?
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07-18-2014, 11:20 PM
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#2 (permalink)
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Master EcoModder
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Woody - '90 Mercury Grand Marquis Wagon LS Last 3: 19.57 mpg (US) Brick - '99 Chevrolet K2500 Suburban LS Last 3: 12.94 mpg (US) M. C. - '01 Chevrolet Impala Base 90 day: 18.73 mpg (US) R. J. - '05 Ford Explorer 4wd 90 day: 16.66 mpg (US)
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Good point. I just got tires for Boxy too, And they're .3 inches larger in diameter than the old ones (Old: P205/75R15 - New: P225/70R15) so I may need to change the mileage readings.
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07-18-2014, 11:22 PM
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#3 (permalink)
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Master EcoModder
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I need to swap out my gear. I have upsized tires now so I'm sure I could get about an 3% improvement.
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Aiming for 50 MPG from an automatic.
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07-19-2014, 10:24 AM
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#4 (permalink)
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Why isnt this in the unicorn section?  |
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07-19-2014, 11:38 AM
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#5 (permalink)
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EcoModding Lurker
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Should it be in the unicorn section?
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07-19-2014, 01:37 PM
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#6 (permalink)
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Master EcoModder
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Quote:
Originally Posted by narclepticfool
Should it be in the unicorn section?
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Instant fuel economy savings by changing speed-o gear, tonight at 5.  |
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07-19-2014, 01:49 PM
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#7 (permalink)
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He's saying that because of the upsized tires you're counting less miles on the odometer than what you're actually going so once you change the gear for the correct one you get an accurate odometer reading and your FE will "increase" because you're calculating it correctly. For example:
On the stock tire size when you go 1 mile the odometer will read 1 mile.
On tires that are upsized when you've traveled 1 mile the odometer will read it as less than 1 mile because the amount of revolutions are lower.
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07-19-2014, 03:51 PM
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#8 (permalink)
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Human Environmentalist
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How difficult was it to change out the speedo gear, and is it located in the rear differential?
A few large bolts let loose in the rear differential of my Dodge 2500 a while back, and messed up some of the teeth on the tone ring (speedo gear). I don't know where to get parts for it, or how to swap it out. Perhaps I should just get a junkyard rear diff.
Tone ring and sheared bolts
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07-19-2014, 04:24 PM
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#9 (permalink)
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Master EcoModder
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Ouch!
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07-19-2014, 07:20 PM
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#10 (permalink)
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I know, it wasn't really a change in the actual milage that the truck was getting, it is just that the numbers now reflect reality! Hooray!
Redpoint: That looks like it sucks. In my Tacoma, the speed gear is in the output of the transmission, and is held in place with one bolt. It is extremely easy to change out. Yours looks more complicated. Also, the speedo gear itself is plastic, not metal like your tone ring. Also, nice bike!
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