Greetings,

Okay, so I nurse 180 mile tank at around 53 MPG finally!!! Then drive 6 miles in the city catching 8 reds on an uphill incline and drop my MPG to 46 MPG (according to the readout) for 7 minutes of time. Now, 200 miles later, of pure freeway driving where the I-MPG reads average of 75 MPG (everytime I look at it, nearly constantly)... and I've only made up to 48.5 MPG. I also had 3 coworkers in the car with me.

It it really possible to be at 53 MPG and have a few (minor) accelerations drop you by 8 MPG and require 200+ miles of perfect hypermiling to make it back up? Perhaps the readout isn't really very accurate? Because, by that logice, if I did it 10 times or so, I'd be on an empty tank but that doesn't happen.

Whey is it so *easy* to lose many MPG just by catching even 1 red, and it is nearly impossible to make it back up?

Apart from that incident, I can maintain my 53 MPG going up hill and through stop signs, in stop-and-go traffic, and light city driving ( ~2 miles from freeway to home/work) for 180 miles. I think I'm otherwise getting the hang of it.

Thanks,
Shawn

 

I believe a lot of this is the deceptive nature of using "MPG" as a unit, instead of gallons per [100] mile, which is more intuitive for figuring out actual cost. The difference between 10 and 20 mpg is 3 gallons after 100 miles. Conversely, going from 50mpg to 100mpg will only save 1 gallon, but looks more significant than going from 10-20 on a linear MPG graph.

Or, look at it this way, if you go up a hill at 20mpg, and back down the same way with the engine off (infinite MPG), the best you can possibly average is 40mpg.

(180mi)/53 MPG = 3.40 gallons consumed

After the red lights you were at:

(186)/46 MPG = 4.04 gallons

That means you'd have to have burnt .64 gallons, or about 10mpg which seems extremely high. If you spent an equal time accelerating, and braking (unlikey), you'd have to have averaged 5MPG on the display for that to be correct, which would be hard even doing repeated 0-60-0 cycles up an incline...

 

What you post seems kind of steep for a drop off with that many miles on the tank? Are you sure you didn't hit the trip meter to B or something. I notice that with my driving style my first 100 miles on the each tank generally sucks as job is only about 10 minutes or less from where I live. When traffic is right during rush hour on the freeway and late at night is generally when I kill the EPA numbers. I wouldn't worry about it to much the most I have seen my displayed off by was 4.5mpg after calculating. Not sure what happened but, I have never seen it off by that much again.

 

ShawnB

Because you have an 06 hch, could this be your situation? I pasted it below. Also included the link......

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This was the 62 mile bug.
Zero one of your trip meters.
Drive for the best MPG you can - like drive on a flat highway at 55 MPH for 61 miles.
At about mile 61 notice the MPG meter.
Starting at mile 62 start driving to get VERY bad MPG, like racing up a hill for a few miles, or start and stop driving in the city, flooring the accelerator with the AC on.

If your car was one of the ones that had the bug and the bug is not fixed you will suddenly get MPG that is VERY low, like 20s or 30s.
This is because the bug makes it start averaging from scratch at about mile 62 even though the MPG meter continues to advance to 63, 64, 65 etc.
So even though the meter is displaying, say, 65 it is only averaging together the last 3 miles of driving.

If your car never had the bug or the bug was fixed your MPG will go down but not as drastically (maybe only around 10 MPG lower by mile 65.)
this is because it is operating correctly and averaging ALL 65 miles together, the 61 good ones and the 4 bad ones.
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https://www.greenhybrid.com/discuss/...hlight=61+mile