Thoughts and Questions About New Ultragauge

[SentraSE-R]

Originally Posted by jeff88

When I am cruising at 65 and I put the trans in neutral the UG shoots up to some crazy MPG # like 300. But at lower speeds, the MPG in neutral is lower (like 250, 200, sometimes less than 100 at lower speeds). At first this made sense to me, because I have more momentum from the higher speed, but after thinking about it and verifying today, the engine revs at ~1,000 RPM no matter what speed once I put it in neutral. So my question is why I get higher mileage at higher speed (in neutral) compared to lower mileage at a lower speed (in neutral)?

Thanks!

Because you're traveling a greater distance per given amount of time, and per given amount of fuel used at idle , at the faster speed.

To answer an earlier question in this thread, don't use a kill switch with most automatics. They typically have to have their engines running to lubricate their transmissions.

[Allch Chcar]

I bought an Ultragauge early this year. Besides being cheaper, the display was bigger and it fit more gauges. Accuracy seems to be slightly off due to rounding but nothing significant, maybe a half mile over 200 mile trip. Then again the average MPG doesn't match up with the actual MPG from using the standard method(miles driven / gallons added). It's always a bit high. I've noted this most fillups and even recorded it. I need to compile the numbers to see if there is a fixed percentage or it's an error during certain operation.

With the Mazda5 I found there is a sweet spot at about 30-40% load where the timing advance hits 50-60 degrees and MPG shoots up into the 40's sometimes 50. I can't do too much about it in town or on the highway but I've managed to get fantastic mileage on country roads.

[jeff88]

Thanks for your experience.

I am still working on calibrating it properly. In fact, just today, I went and looked at the forum/support/manual webpages to try and get it going right. My average MPG on the UG is definitely always more than the miles/gallons calculation (like 6-8 MPG more). I should record those numbers and reset it each tank like you have.

I wonder if the 30-40% load is a *relatively* universal load % across different cars (e.g. is my corolla the most efficient at 30-40% too?).

[jeff88]

I have officially hit 3300 miles since installing the UG!!! I found out when the oil change alarm came on (I didn't even know it was set up)!

Anyway, 3300 miles later, I am finally calibrating it properly. Tonight I calibrated the distance. I don't have any mile markers nearby, so I had to use Google for distances, which of course, has some error built in. My trip was 4.2 miles, and I calibrated it for 4.225, just to give a little buffer. I did it 3 times, so hopefully it will work out.

I just got a fill-up today, but I forgot to hit the up button to reset it. Dratz! So at my next fill up sometime next week, I will add in the amount of fuel used (pumped) into the 'calibrate mpg/fuel' menu? Or should I wait until the fill-up after that, when I reset the UG properly?

[nemo]

Originally Posted by jeff88

I just got a fill-up today, but I forgot to hit the up button to reset it. Dratz! So at my next fill up sometime next week, I will add in the amount of fuel used (pumped) into the 'calibrate mpg/fuel' menu? Or should I wait until the fill-up after that, when I reset the UG properly?

On my car the gauge recognizes the fill-up as can be see by the distance to empty resetting. Which reset are you referring to, the trip gauges or are you required to manually enter the fill-up? Even if manually entered fill-up is required, on the next tank just add the gallons from the from both fills and enter.

[wdb]

Precision != accuracy.

I think it's important to point out that a UG or SG display value is only as good as the data it gets. Both devices are reading data from the car's computer, which is reading data from sensors spread throughout the car. The abililty of the sensors to accurately translate physical phenomena to voltage, and the quality and -- very importantly -- the resolution of the analog-to-digital conversion of those volts, combine to become the source of the data you see on the gauge.

So, for example, If you have a speed sensor + A/D converter combination that is capable of producing figures with an accuracy of +/- 1MPH, the fact that your Ultragauge is capable of displaying MPH in tenths is literally useless. Not only that, you should expect to see the numbers go up or down by 1 or 2 MPH.

But wait, you say. Some cars have digital speedometers, and I don't see them jumping around! That's because the manufacturers have beaten you to the punch, and they've thrown some averaging gizmoid in there to 'smooth' the output so that it doesn't jangle the poor driver's nerves. I can't say for sure but I doubt UG/SG does much in the way of smoothing - they probably just repeat the raw numbers they're fed.

then factor in the SG/UG doing calculations of its own, such as MPG. Now you're adding even more uncertainty and variability to the output.

So I'll repeat something I've said before. SG/UG, used as relative measures, are extremely useful as tools to gauge how your driving style affects gas mileage. If you start comparing the numbers they produce to the numbers you see from other instruments and expecting everything to line up all honky dory, you will drive yourself needlessly crazy.

Calibrate them by all means, but don't expect perfection. Get them close, then leave the calibration settings alone and start comparing driving style to the numbers you see on the UG/SG. That's where the real value lies.

[mrmojo]

I know this thread is a year old, but given that I have a 2002 Chevy Prizm/Toyota Corolla and just started using an UltraGauge (UG) myself, I find this discussion still relevant and deserving of a bump.
1. So far, I like the UG, if for no other reason than (a) it was 1/2 the cost of a ScanGauge (SG) and (b) it's nice to finally have useful feedback instrumentation.
2. Re: calibration and accuracy: If the factory speedo is out of cal , whether by design or not, it seems like calibrating the UG using mile markers would provide more accurate FE data. But I'm hesitant to use those numbers when I post in the Garage, as I started off using factory odometer miles/petrol station gallons. If I started posting the UG data, I'd look like a FE god without doing anything but changing my data source.
3. The number of gauges is rather overwhelming. I monitor the basic parameters, but there are many others which may help my FE, and I am ignorant as to which would be helpful.
4. Anybody have a lot of experience with UG that has set it up have any advice which parameters are more useful for FE?
5. I wish I would have checked out the UG website in more detail before I bought the gauge; they have sections for installation videos, usage videos, and even a form. Problem is, the video sections are "Coming soon!" and the forum has been closed! To me, a company that sells an instrument with this much ability should be able to help out the buyers as advertised. Just my 2 cents...
5. Overall, I'm happy with having feedback and a tach (finally!), but if I can't get some real accurate data from it, I might sell it and buy the SG instead.
Thanks for reading.

[user removed]

Nothing crazy about 300MPG coasting in neutral. My Fiesta uses .17 GPH at idle. If I shift into neutral at 68 MPH (68/.17) I am getting 400 MPG as long as I am at 68 MPH as my speed drops to say 51 MPH (51/.17) I am still at 300 MPG. Only when I coast down below 17 (17/.17) MPH in neutral does my mileage drop below 100 MPG.

reagrds
Mech

[nemo]

Originally Posted by mrmojo

2. Re: calibration and accuracy: If the factory speedo is out of cal , whether by design or not, it seems like calibrating the UG using mile markers would provide more accurate FE data. But I'm hesitant to use those numbers when I post in the Garage, as I started off using factory odometer miles/petrol station gallons. If I started posting the UG data, I'd look like a FE god without doing anything but changing my data source.

I see no reason not to use the more accurate information. Note the percentage difference for the miles if any then you can apply that to your old numbers for a more direct comparison.

Originally Posted by mrmojo

3. The number of gauges is rather overwhelming. I monitor the basic parameters, but there are many others which may help my FE, and I am ignorant as to which would be helpful.

4. Anybody have a lot of experience with UG that has set it up have any advice which parameters are more useful for FE?

Everyone has their favorites. Instantaneous FE, Load and GPH are some of what is on my first page. Instantaneous FE is the most watched for me.

Originally Posted by mrmojo

5. I wish I would have checked out the UG website in more detail before I bought the gauge; they have sections for installation videos, usage videos, and even a form. Problem is, the video sections are "Coming soon!" and the forum has been closed! To me, a company that sells an instrument with this much ability should be able to help out the buyers as advertised. Just my 2 cents...

Yep, the general forum is close, only the install seems to be open. Probably the Admin got tired of all the I can't get it to work posts. Wonder if the Android phone are taking a bite out of business.

[mrmojo]

Originally Posted by nemo

I see no reason not to use the more accurate information. Note the percentage difference for the miles if any then you can apply that to your old numbers for a more direct comparison.

That's a good idea; time to fire up Excel.

I know one reason for the difference was the distance calibration; the cal factor went from 1.000 to 0.996.

Originally Posted by nemo

Everyone has their favorites. Instantaneous FE, Load and GPH are some of what is on my first page. Instantaneous FE is the most watched for me.

How does load help? I've also read about throttle position (TPS), but again, my ignorance comes to the front of the line.

Originally Posted by nemo

Yep, the general forum is close, only the install seems to be open. Probably the Admin got tired of all the I can't get it to work posts. Wonder if the Android phone are taking a bite out of business.

Why would Android take a bite out of business? Is there an app? Does someone make a connector cable? Tell me more, tell me more!