most cars that calculate avg mpg dont need to go 100 mph and coast....the 99 mpg can be achieved at just about any speed, as long as you dont have to hit the gas for about 10-15 seconds.

today I fueled up...took 14 gallons, and the DIC said "distance to empty 480"

is that the max it will read? My 94 Lincoln could sometimes get up to 511-514 miles to empty, but it had a larger fuel tank.

I was unaware that the "instant mpg" feature was a 08 addition. It is useless, unless you are curious as to what kind of mpg your car achieves during sustained speeds...say for example, if you can achieve inst mpg 32 at 65 mph without fluctuating the pedal, you can then determine.....NOTHING!

 

I have only reset my MPG DIC 3 times that I have Had this car. it stays right a 27.? If I go to the coast it will get to 28.? on a drive to Daytona if I start out at 27.3 drive to there and back it will show 27.7, ALL hyway 82m round trip at 70-75mph I did this today. When I do the gal.per miles at fill up very close with the DIC showing about .3 better then the math. I think that is good as I don't drive for MPG I just drive it when it says low fuel I fill it up at a station that is cheap!

 

This will probably be government mandated feature soon. Make us feel guilty about having fun while driving.
In Canada its kind of reversed, Litres used per 100kilometres. The most I have gotten instantaneously is 32L/100km on a highway sprint to full speed. You guys could try switching it to metric and we can have a contest to see who can get the highest(worst) fuel economy, first to 99 wins

 

I've been using this feature more since seeing this thread. Of course it doesn't give you anything substantial to argue with, but it feels like I am doing well when the Instant MPG is more than the overall average MPG.

If I know my average is 22.2 (as it was this morning after idling for 10 minutes while the car warmed up) and I look down to see the instant MPG showing 32 then I feel like I am helping bring up the overall average.

If I look down and it's at 18 or 20 then I know I should let off a little and sustain my speed instead of gaining on the guy ahead of me.

I'm sure it's all psychological, but I bought the HHR to get improved gas mileage over my old Dodge Magnum. I'll take any gains (real or imagined) as a victory.

 

Hell, I rarely use it, i figure I bought the car and have to put gas in it anyhow

 

You can't use it, not available on the 06. Only the 08 HHR has this feature.
You're probably refering to the AVERAGE MPG.

 

It is a very useful tool to moniter your milage if you are trying to maximize it. You can find the sweet spot to get the best compromise to speed vs mpg on the highway. A vacuum gauge can also serve this purpose, hightest vacuum gets the best mpg. The SS has both features.

 

Yes, but the vacuum guage's main purpose is as a boost guage. Supposedly a turbo is a gas saver because it is free energy. It may be interesting to see how instant mileage reacts as you are in boost, instead of vacuum.

 

Mine had read over 500 before. Just depends if the entire tank was highway driven or not.

 

Having a turbo is definitely not free energy. It is just a more efficient means of forcing air into the engine than a supercharger. Once that increased volume of air is in the engine, it still needs more fuel to increase power and maintain the ideal air/fuel ratio. That is why turbo engines get worse fuel economy than a non-turbo variation of the same engine.