Davalos Posted July 25, 2009 Share Posted July 25, 2009 hey Folks! Anyone ever try installing one of these gas mileage meters on an EA82 or EA81? Is it even possible? There seem to be a few options out there ... but I dunno if there's even anyplace to plug into ... Anyone ever done this? I've been "Hypermiling" lately and have been getting 34mpg out of mine for the past few tanks. I'd love to see it in real-time. Quote Link to comment Share on other sites More sharing options...
nipper Posted July 26, 2009 Share Posted July 26, 2009 Im a bit confused, this is in the older gen board, but that is for OBDII (at leats they list leagcy settings). Why not use a vacume gauge, as that was the original MPG gauges (and still are). nipper Quote Link to comment Share on other sites More sharing options...
Niku-Sama Posted July 26, 2009 Share Posted July 26, 2009 why not calculate milage divided by gallons filled at the pump? Quote Link to comment Share on other sites More sharing options...
Txakura Posted July 26, 2009 Share Posted July 26, 2009 why not calculate milage divided by gallons filled at the pump? because he wants to see a real time display of his current consumption Quote Link to comment Share on other sites More sharing options...
Davalos Posted July 26, 2009 Author Share Posted July 26, 2009 Right. Aside from the "hey kinda cool!" factor, I'd like to get some immediate feedback on what my mileage is in real-time. I mean, i can get 46 mpg if I drive from on gas station to the next on the expressway doing 55 ... but that's a no-brainer. I wanna see what hills do, what coasting does, slamming on the gas, sitting @ lights, etc. It might not be worth the cost, but it'd be a good feedback mechanism. I do the "per-tank" thing already. And I have gotten anywhere from the 18s to the 30s in mileage. And you're right - that device I posted was for OBDII plugs ... but its as close as I could get in a quick search - I wanted to see if you folks had done anything close to that already, or if I was gonna start from scratch. Where can I get more info on Vacuum gagues? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 26, 2009 Share Posted July 26, 2009 Where can I get more info on Vacuum gagues? You just plumb one into the manifold and you try to keep the gauge as high as possible - manifold vacuum decreases as the throttle opens. High vacuum = closed throttle - Low vacuum = open throttle. A vacuum gauge can also tell you a lot about the condition of the engine - if you can read one.... GD Quote Link to comment Share on other sites More sharing options...
zukiru Posted July 26, 2009 Share Posted July 26, 2009 something like that will work best on a multiport FI system. I'm guessing from your mileage you must be TBI and not carb. Quote Link to comment Share on other sites More sharing options...
casm Posted July 26, 2009 Share Posted July 26, 2009 because he wants to see a real time display of his current consumption Not strictly Subaru-related, but it does apply here. My Jeep has the overhead console that does all the temperature / compass / fuel consumption stuff. In all honesty, I've never found the instant fuel consumption readout at all useful except for telling if I'm driving into a headwind or not. Sure, it'll tell me I'm getting 10mpg uphill and 45 downhill - but it's really the average that counts, since that points more to a potential issue. Frankly, doing the divide-distance-travelled-by-gallons-in-the-tank is likely going to be a lot more useful for him. Also, from looking at the site for the device, it won't work on a carbed vehicle. My old Peugeot 505 (which had mechanical injection) had a device called an Econoscope that purported to tell you if you were driving too hard, but it was frequently inactive and / or inaccurate. It worked off of engine vacuum and something similar could probably be rigged up for a carbed Soob, but again it comes back to the usefulness of an instant readout. The cool factor is definitely there, and I do remember seeing a junkyard Brat with something similar (but not as fancy). No idea if it worked or not, but from the buttons it did basically what you're looking for. Not sure how it would tie in to an EA-81 (again, I'm guessing vacuum), but it might be something to research if you're gung-ho on the idea. Quote Link to comment Share on other sites More sharing options...
soobiefreak85 Posted July 27, 2009 Share Posted July 27, 2009 Right. Aside from the "hey kinda cool!" factor, I'd like to get some immediate feedback on what my mileage is in real-time. I mean, i can get 46 mpg if I drive from on gas station to the next on the expressway doing 55 ... but that's a no-brainer. I wanna see what hills do, what coasting does, slamming on the gas, sitting @ lights, etc. It might not be worth the cost, but it'd be a good feedback mechanism. I do the "per-tank" thing already. And I have gotten anywhere from the 18s to the 30s in mileage. And you're right - that device I posted was for OBDII plugs ... but its as close as I could get in a quick search - I wanted to see if you folks had done anything close to that already, or if I was gonna start from scratch. Where can I get more info on Vacuum gagues? I can see why you want to do that, that is a big range. Quote Link to comment Share on other sites More sharing options...
nipper Posted July 27, 2009 Share Posted July 27, 2009 You just plumb one into the manifold and you try to keep the gauge as high as possible - manifold vacuum decreases as the throttle opens. High vacuum = closed throttle - Low vacuum = open throttle. A vacuum gauge can also tell you a lot about the condition of the engine - if you can read one.... GD What he said. It's amazing how much MPG you cna pick up by retraining your right foot to squeeze the gas pedal instead of just pressing it down. You can recalibrate the way you accelerate and no one would really notice the difference. This is still how basic (in dash) MPG meters work. They just read manifold vac, the higher the needle, the higher the instant MPG is. ALso you can find the cars sweet spot. nipper Quote Link to comment Share on other sites More sharing options...
ihscout54 Posted July 27, 2009 Share Posted July 27, 2009 You are probably looking for a digi unit with a speed input but, something like this little vac gauge would do the trick. It probably lets you rotate the face for "calibration" Im guessing. http://www.carparts.com/MILES-PER-GALLON-GAUGE/GP_2008961_N__10618.car Quote Link to comment Share on other sites More sharing options...
Davalos Posted July 27, 2009 Author Share Posted July 27, 2009 You are probably looking for a digi unit with a speed input but, something like this little vac gauge would do the trick. It probably lets you rotate the face for "calibration" Im guessing. http://www.carparts.com/MILES-PER-GALLON-GAUGE/GP_2008961_N__10618.car That's sweet. Yeah, a digital one would be cool, but I gotta take what I can get apparently. I mean, vacuum alone can't be the only thing, because it doesn't compensate for speed. but it WOULD be at least a start. It at least seems like it would give me the info "This is the Best Mileage you can get under these conditions", and as long as I keep the needle to the best mileage potential, that will appear when I do the miles-per-tank calculation. The "Hey Cool" factor might just have to wait. This is something I can do easily enough, yes? Is it just a mount-n-connect? I'm sure there's a vacuum output I can find ... Quote Link to comment Share on other sites More sharing options...
zukiru Posted July 27, 2009 Share Posted July 27, 2009 I think that vac gauge with the mpg on it has a cool factor. Quote Link to comment Share on other sites More sharing options...
zyewdall Posted July 29, 2009 Share Posted July 29, 2009 Not strictly Subaru-related, but it does apply here.In all honesty, I've never found the instant fuel consumption readout at all useful except for telling if I'm driving into a headwind or not. Sure, it'll tell me I'm getting 10mpg uphill and 45 downhill - but it's really the average that counts, since that points more to a potential issue. Frankly, doing the divide-distance-travelled-by-gallons-in-the-tank is likely going to be a lot more useful for him. It depends on whether the potential issue is with the engine, or the driver -- engine issues are more likely to be found by the per-tank mileage, but problems with the driver (lead foot, etc...) are more easily narrowed down by the instantaneous mlieage. Quote Link to comment Share on other sites More sharing options...
keppelk Posted November 15, 2009 Share Posted November 15, 2009 Resurecting an old thread because I just stumbled across the MPGuino too. Going through the FSM for my '86 Vortex (XT 4-cyl turbo), I found that the trip computer has a speed pulse line. Since turbos are MPFI I have an injector wire too; so have all the inputs I need (tap injector signal #1 as it comes through the firewall en-route to trunk mounted ECU). Can easily tap into power via the stereo harness (+12V constant and ground). Not sure if there is a speed pulse signal generated in other models without the trip computer? If there is, then no reason you can't use an MPGuino. There is an OBD-II version too, for the younger Subaru. Quote Link to comment Share on other sites More sharing options...
gadberry Posted November 19, 2009 Share Posted November 19, 2009 check out the Subaru's included on this list of great MPG cars from '78 to '81 http://www.mpgomatic.com/2007/10/08/super-cheap-high-mpg-cars-1978-1981/ I almost certain I'm not getting 40 MPG in my '81 GL.. cheers, Quote Link to comment Share on other sites More sharing options...
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