Biggest MPG error you've seen on your uncalibrated gauge? (Nissan X-trail SG/UG)

[MetroMPG]

Same setup options.

[Cobb]

I never used my sg2 for mpg, but for the other gauges. I think the 9999 is what made me assume it would not be accurate in the very first usage.

My gen 2 insight is always 2-3 mpg higher rather in sport, eco or using a mix of ethanol and regular fuel.

Originally Posted by wdb

My SG reports 9999mpg when I am in DFCO and actually getting [infinity]mpg. That is by far the largest error I've seen.

[oldtamiyaphile]

Originally Posted by Cobb

I never used my sg2 for mpg, but for the other gauges. I think the 9999 is what made me assume it would not be accurate in the very first usage.

This has probably been mentioned before, but when MPG goes to 9999, SG still knows you're burning 0 and travelling X miles, which are the numbers used in it's calculations. It's a quirk of the display, not the underlying logic.

If you set it to metric, DFCO will simply show '0.00'. MPG is of course a non-sensical measure anyway.

[ever_green]

Even my car's on board trip computer is off by about 4-5% everytime. No device can measure MPG accurately. However I love how my scangauge is now accurate to +/- 1% after several calibrations. I just love this piece of hardware.
9999 MPG is normal, that means fuel cutoff. You have to set your fuel cutoff settings up first. It should be approximately 4 points above your TPS value at idle.

[oldtamiyaphile]

Does the X-Trail have a throttle plate?

My plateless petrol Fiat is out by a 30% as well, and my TDi changes wildly over each tank from 8%-30% despite being driven in much the same way over much the same roads.

I wonder if changing the engine size parameter rather than cailbration yields more accurate results? On the 2.5TDi I seem to get more accurate readings if I enter 2.0 as the engine capacity and then only add a 1-2% of calibration. Thoughts?

[MetroMPG]

Good question - I'm not sure if it has a plate or not. Will have to research...

[Cobb]

How is the Rogue in regards to performance and hauling? I had a Nissan dealer willing to sell me one starting at 17 grand for last years model with 40k miles on it. Looking online it seems many of them have engine problems before approaching 50k miles. That and when the sales person clicked the dash for sport mode it didnt seem to be more sporty, but you could hear the boost from the tubo. Thinking maybe it didnt have 93 octane in the system as I know many gas stations only sell 91 and some still use 87 as they are cheap.

Looked like a rounded SUV like and I am afraid the roundness may make it too difficult to haul too much inside like how the gen 2 insight is.

Originally Posted by Old Mechanic

The wife regularly averaged 27-28 in her Rogue.

[mechman600]

When I am in town, doing lots of EOC and P&G with my Civic, the SG is 25% out, and when I go on a road trip and drive it HARD, it is out by 14%. Goes to show how much of an estimate the OBDII gauges really are.

[dmt257]

My Insight has been as much as 6mpg off on a real mpg of 64. Last tank it was only 2.5.

I'm trying different brands of fuels to see if that makes any difference.

[brucepick]

Originally Posted by YeahPete

My scan guage turns off when I try EOC. . So I really don't know much better my mileage is if I tried EOC.

There's a pretty easy fix for this, for the ScanGauge.

Go into the settings, what you need is in the "Fuel" or "Fuel Type" section. Select "Hybrid". That solves the problem.