Civic HX and Scanguage?
 

A little background: I'm looking to buy another FE car that will eventually replace my partner's '89 Corolla GT-S. For the time being, having this other car will keep her from driving my VX (and lowering its mileage) as the Corolla is out of town. I'd like the car to be a Metro, but she says no way to that idea. Another VX is also not an option, as she says my car is ugly and slow. I've also been itching to have a Scangauge as I'd really like to know whats going on fuel-wise while I'm driving. I know there's the SuperMid, but I want the plug and play of the Scanguage.

At first glance, the Civic HX seems ideal as they are 1996+ and OBD-II compliant. It would seem like an HX driven (by me) with a Scangauge would come close to the mileage I'm getting now with my VX, as well as reform my VX driving techniques.

So, does anyone here drive an HX with a Scangauge, or know of someone who has had such an experience? I've done a few searches and didn't see anything about this combination. There was a old post on Greenhybrid.com that said that the lean-burn of the HX's VTEC-E would throw off the Scangauage's MPG readings.

You could just make her walk and then see what she says about being in an ugly car. Why do people always complain about things that aren't theirs. Where's her car? You get what makes you happy! You're the MAN!

Amen.

Adam -

I *may* have noticed the same behavior. I have been testing the EFIE, which allows me to put a bias on the 02 sensor. I also have a digital A/F ratio gauge.

When I idle the car in the parking lot, I see a steady 14.7 stoichiometric fuel ratio on the gauge. It does fluctuate a little, but it is overall very consistent. On the scangauge I see 0.3 GPH. When I switch the display to liters, I see 1.3 LPH. When I turn the EFIE on (I have a switch for it), I see the A/F ratio creep up and eventually go over 20.0, aka lean. However, the GPH stays the same. When I convert the scangauge to liters, the LPH is still 1.3 LPH.

My expectation was that the LPH would drop down to at least 1.2 or 1.1 LPH, but it doesn't. This makes me think that the scangauge algorithm is "missing something" when it comes to lean burn. Maybe that happens in the HX too.

CarloSW2

I've had a '97 HX for about six weeks and am getting ~50mpg without much modification. Mostly commuting at 65mph but using AC occasionally and getting stuck in a few traffic jams. Planning on getting a Scangauge soon. I'm thinking if I stripped out the AC system and did some aero mods I could get near 60mpg.

Sean

https://www.cleanmpg.com/forums/scan-...html#post40053

The SG doesn't recognize lean burn. Unless you try to compensate by adjusting the offset values for fuel, you'll see under-reported fuel consumption. (Assuming you get into lean burn mode regularly.)

Be sure to let us know how it works out when you get the Scangauge.

Thanks for the rest of the info guys, I'm not sure what my plans for the second FE car is now. I guess there are always the TDIs, but those command quite a premium around here.

To answer about the missing Corolla, it's up in Seattle. She takes the Amtrak Cascades train back and forth each week, leaving it up there. Of course this is good because it saves gas, but is inconvenient because of the car issue.

Even though its this way it shouldn't be a huge issue. If you drive consistently you'll still see decent accuracy simply by calibrating the SG over 5 or so tanks.
My scangauge got reset the other day after getting it calibrated I noticed that the miles reported were not always accurate but the mpg reported was within .5%. Which is good enough for me. Basically I think the SG will be set to show an average between leanburn and regular. This number will gradually go up as the owner gets more adept at controlling leanburn. Which means an FE surprise every time you pump! yay

It looks like you may be right, lovemysan. I emailed Scangauge (Ron DeLong) about the HX and received this response:

"People who have used the ScanGaugeII have not noticed a significant error in the fuel economy in the HX. During very low fuel flow, the pulsewidth of the injectors gets extremely short and the transition time from off-to-on and on-to-off starts becoming a significant part of the injection time. The algorithm we use is able to compensate some of this out, but to some extent this is a characteristic of the injectors and drive current to them, so linearity at the low-flow end does suffer.

Luckily, the majority of the fuel is used at the higher pulsewidths so, the net error over a trip or tank of fuel is very small even though the instantaneous error during lean burn is higher."

I think I'll leave the HX in the running for the next car purchase.

I got the SGII installed last night and will be starting to calibrate and collect data. If there are any specific experiments you want me to run let me know. BTW, I'd definitely keep the HX in the running. I've been able to get 49mpg with minimal mods and only basic driving techniques. I'm putting a grill block on tonight and hope to get over 50mpg.

Sean

Sean,

How did the Scangauge work out?

Working out alright. I especially like the temp displays after doing all the grill blocking. The mileage readings are a bit different than the SMID since it's based on RPM as others have mentioned here. I'm on the second tank and am getting it pretty closely calibrated for my driving style and the commuting route. BTW, I'm in closed loop pretty much all the time except for the first few minutes when starting cold.