ScanGaugeII Throttle Cut Off and MPG Calibration - Fuel Economy, Hypermiling, EcoModding News and Forum

ballegre · 06-24-2008, 07:45 PM

First post here...New SGII on 2006 Honda Pilot.

I know MPG needs calibrating - finishing up my first tank. However, I noticed a 9999 display when I know I maintain (not accelerate) the throttle (below TPS 24). If I'm on a flat or slight incline and maintain throttle position I can hear the engine on and feel it but SG still reads 99999 and 0.0 GPH - can go on for quite a while. This results in much higher MPG calculations (I doubt I'm getting 30+MPG on this guzzler).

My question is should I consider lowering the TPS cut off or just calibrate at fill ups until I get an accurate approximation? I suspect there's no simple answer here but I would like to know others opinions either way.

Also, is there an "absolute" TPS cut off value or is it relative to SG implementation. In other words, if it's absolute then in theory Honda should be able to tell us the real cut off value. If it's a funny number that SG calculates then I guess there is no absolute just a continuous guessing game.

Thanks for a great forum!

ballegre · 06-24-2008, 09:22 PM

Edit: Just filled up and SG was 15% optimistic so I fixed that. The idle TPS is 14. I'm reading now on cleanmpg where some folks are recommending cut off set to idle TPS plus 4...appreciate any advice.

MetroMPG · 06-25-2008, 12:14 AM

ballegre: does your Pilot have cylinder deactivation? I believe some models did, and based on your description of light load & low TPS when it occurs, that's my first guess. The SG may not know how to handle it. I know this was a challenge for them with other multi-displacement engines.

ballegre · 06-25-2008, 12:28 AM

Quote:

Originally Posted by MetroMPG

ballegre: does your Pilot have cylinder deactivation? I believe some models did, and based on your description of light load & low TPS when it occurs, that's my first guess. The SG may not know how to handle it. I know this was a challenge for them with other multi-displacement engines.

Yes it does (so-called economy mode). Forgot to mention that.

NeilBlanchard · 07-03-2008, 10:30 AM

Hello,

I got my SG II a couple of days ago, and the MPG is way too high -- it says I'm getting 56mpg, while I'm pretty sure it is actually 42-43mpg. And the miles left in tank says 530 miles (!!) while I know that it is probably 210-240 miles.

I set the tank size to 12 gallons (the manual says 11.9). Or, should this be set to the "working" size, which is ~10.5 gallons?

Also, the off position for the throttle on my Scion xA is 12 -- I had it set to 16 as per their recommendation, but I have lowered it to 15. Should I go lower?

PaleMelanesian · 07-17-2008, 05:35 PM

Watch the MPG and Loop gauges together. It should go to 9999mpg at the same time as it goes Open Loop. Adjust the cutoff until they match.

I use 10 gallons. It really doesn't matter, though. The only thing that affects is the miles / gallons remaining.

azraelswrd · 07-17-2008, 06:11 PM

I thought we were supposed to undervalue the tank size, so since we're in an xA and the tank is supposedly 11.9, I went with 11 (though thinking back maybe I should have went with 10.5). I'm still working on my 2nd tank to retool the adjustment factor. (By my calcs, earliest I can refuel is in Aug)

NeilBlanchard · 07-17-2008, 10:13 PM

Hello,

Yes, I went with 11 gallons, too -- but on the two tanks that I had to calibrate it, I've had to adjust it up (quite a bit!), so you may be better off setting it to 12 gallons to start.

BTW, with only the one tank to calibrate it, it read 48.6mpg, when I actually got 47.5 -- which is a new high for me! It calculated that I had used 10.4 gallons, when I had actually used 10.7.

I went 509.3 miles on one tank of gas -- awesome, if i I say so myself!

PaleMelanesian · 07-18-2008, 11:55 AM

Great work! That's a big accomplishment.

ballegre · 07-18-2008, 03:46 PM

Well, I've been using the SGII on the Pilot now for a few weeks and it's still not calibrated properly. First tank was optimistic, second pessimistic, third optimistic, etc.

I took it on a family vacation from NC to NY and then to the NJ shore. There are lots of variables: 8 people, luggage carrier so full it took three of us to get it shut, car packed to the max

, the variable cylinder feature, and I think there was some E10 gas variations in there as well. According to the SG (I didn't bother manual calculations), I got about 24 MPG (optimistic) on the way there and about 20 MPG back. On the way back it was windy and I'm pretty certain you can only get E10 in NY and NJ. I don't think the county I live in requires E10 but they don't have to label so...

I mostly drafted as P&G resulted in very short glides with that luggage thing. It felt like driving with a parachute. I didn't understand P&G at that time anyway (only recently learned about BSFC, throttle control and smart automatic tranny's). I did see 27 MPG at one point drafting doing 60 MPH. I followed some crazy charter bus driver doing 75-80 MPH for a few hours on the NJ Turnpike and got around 24 MPG (optimistic numbers). With 8 people in the car trip time was a real consideration so speed was important.

I estimated I burned about $250 on fuel for 8 people 1100 miles round-trip. Still the cheapest way to travel (unfortunately).

I'm still trying to calibrate. Now that I'm not traveling and the variable are under control I can get an accurate reading. If any other Pilot owners have experience with the SG please chime in.