I find it frustrating and a little confusing. When I am pulling in my parkade or simply rolling in a parking lot without touching the gas at low low speeds the IM is 0.... when i depress the break it slowly moves to 100... but once i depress the break I do not have enough momentum to carry myself to my parking stall or destination and have to press the gas again.

Why would it seemingly use so much fuel to coast at virtually no speed?

I can fudge around trying to glide with a few bars but at that low speed it is difficult and I end up no better off.

Any thoughts?

 

The engine is running only slightly higher than idle speed when you're moving very slowly (like through a parking lot) hence the low MPG.

I would like to see a forced engine stop feature. Limit the mode to around 12 mph but EV only.

 

The MPG display uses vacuum to approximate the current fuel consumption. It's not an actual measure of miles and fuel flowing through the system. It's a tool to use when driving and that's all.

 

I can only engage EV when I am traveling over 8mph, which also happens to be the
point that autostop kicks in when applying the breaks. So if I am gliding without breaks
as soon as it hits 8mph the mpg drops like a rock but not to zero.

 

All normal cars cut off fuel to the engine when you take your foot off the gas pedal, allowing the wheel movement to keep the engine spinning. But when your speed is so low that the engine can't maintain 700+ RPM then it starts burning fuel again to keep it spinning.

The HCH works the same way, with the exception that pressing the brake while going < 8 mph will usually turn the engine off. If you're going very slow but are not pressing the brake, the engine will burn gas to keep it at 1000 rpm.

 

Are you sure? I'd be willing to bet is uses injector duty cycle and current speed to calculate MPG.

Ron in SoCal

 

Naw, I am not sure. It's what I heard and makes sense. I doubt it would be a very complicated cacluation.

 

ScanGauge uses the OBD2 port which means it's getting the info straight from the engine computer. I don't see why the HCH2's iFCD wouldn't use the computer data.

 

The IM does not exactly function correctly all the time. I have seen the IM go to zero and stay there when I am coasting down a large hill. Usually this is more likely when engine is cold, but I have seen it hot. As was stated, it is just a tool. Not meant to be taken as "gospel"

 

It's not using a lot of fuel. It's just getting poor gas mileage for the very short distance driven. Let's say you're completely stopped with the engine idling, and you do so long enough to use one ounce of gasoline. Since you're stopped, your instantaneous mileage (IM) gauge will show zero and you won't worry about it.

Now let's say that during that time that you used an ounce of gasoline you crept one foot forward. Your gas mielage over that one foot will look awful. (If you want to do the math, an ounce per foot is about 5000 ounces per mile, which is about 40 gallons per mile, which is 0.025 MPG. That's downright AWFUL). But why worry about it? You've still only burned one frikin ounce of gasoline.

By the way, this is just an example. You actually burn a lot less than an ounce of gas when you stop your car for a few seconds or creep forward a couple of feet.