I highly recommend a product called startron.you can find it at most walmarts in the boating section.
I have recommended this to about 50 people and everyone has reported back with great results most tell me they see a 1 to 2 mpg increase not too mention how much smoother the.engines seem to run.
This is very effective at fighting the effects of ethanol.
Last time I calculated the cost it was somewhere around 10 cents a gallon to use.
I started using it mainly since it stabilized the gas in my old cars that I store much better than stabil.
And it also appears to keep fuel filters fuel linear etc on the old cars from rusting out due the ethanol tendency to attract water like a.magnet.
Give it a shot after a half tank of running. I think you will notice a difference in gas mileage and a little power increase

 

I have seen items for sale that look like they swirl the air flow coming in that they claim to increase mpg. One is called Tornado, probably are others. Have any of you tried these and found out if they work at all? $20 for 6 mpg would be a bargain if it's real.

 

Snake oil. If they really worked they would be "flying off the shelves" and every car owner would have one.

 

and the factories would be installing them from the get go.

 

Go to ecomodder.com.
Here are some tried and true mpg mods:

1) Air up tires to 38 psi (or higher, but be careful!)
2) Partial grill block (you have to be smart about this or you could overheat)
3) Warm air intake (you read that right...NOT a cold air intake. You put your intake tube
so that it sucks air from above the exhaust manifold. This has the effect of thinning out the air so that the computer compensates by reducing fuel input...the downside is lower power)
4) Smooth out the front end with duct-tape anyway you can.
5) Boat tail (see ecomodder.com for explanation, pictures)
6) Last, but not least, adjust the nut behind the steering wheel (learn to drive efficiently).

Of the above, I do only 1 and 6.
Number 5 is for your hardcore hypermilers and is usually only done by people with cheap cars like Geo Metros, old Honda Civics, etc.
I would never do 4 because of the looks factor. The HHR is too pretty to mar it up.

 

I'm Down on number 6. Seems like all my cars get better mileage when I don't drive them. Especially the SS. Must have the #6 nut overclocked.

 

I hear that's a common defect on the SSs.
Love your avatar pick, BTW, can you post a bigger picture so I can see the wheels better?

 

Click on the little camera under his screen name, it will take you to his gallery.... SS fan has lots of pics.....

 

Thanks, Greybeard999!
Awesome looking SS, SS fan. Love the color, the wheels and the exhaust.

 

I think that's the problem with my girlfriend's HHR. I get in it, 07 2.2, and it has about 22.5-23.5 mpg average and when I drive it, mainly highway it's getting 28+. And 85% of her daily driving it down the highway to the school she teaches at 30 minutes away.