Since I replaced the stock air intake with the CGS Air Intake and the stock muffler with the CGS Axle Back muffler, I am getting 40.2 MPG on the same 20 mile run I used to get 36.5 MPG with the stock air intake & muffler. This is driving at a sustained speed of 57 MPH with the tach at a sustained level of 2,000 RPM. I did re-set the ECU after the mods were installed.

I use Premium gas, Mobil 1 oil, Wix oil filter, and have Michelin AX Pilot tires.

The vehicle is a 2007 HHR 2LT with the Ecotec 2.4L engine. As of today (Feb 5, 2009), the car has 21,904 miles. I bought the car new on Dec 14, 2007.

 

How can you drive that slow for 20 miles?

 

nice mileage. wish i could get that much right now. only getting about 20 but thats bc im not doing all the hwy driving i usually do and just doing little short trips. good luck on gettin that higher.

 

i have 08 2.4 auto 2lt , i have never seen 29mpg and i try real hard. i tryed the premium for a week, over $120 worth , 1 day according to my calculation not the dic dash thing , i got 31mpg. it was foggy , so i did alot of 62mph in a 70mph zone. my dash still read 28mpg.

 

The DIC sometimes reads inaccurately. I wish there was some description on how it works.

The DIC, for me reads lower than what is calculated, usually by 1 or 2 mpg. Since I'm anal about gas mileage, my overall mileage has been 30.3 mpg in the 40,000 miles I have put on the car.

 

If there's 4" of snow on the road that's nearly top speed.

 

I get 40mpg going down hill

 

i check /calculate my milage everday 6 days/week , 270+ miles/day , my figures are 98% match or better to the dash. it is pretty good , just not quite perfect. i was jealous of the 40mpg , so i did 57mph on half of my route today the speed limit was 70 , it was hard for me. my result was 31.5 on the dash. i won't know my total average until i fill up again tomorrow. it will probably be 29 , because i sped up on the 2nd half , and it is reading 28.2 now.

 

Maybe that's as fast as he can go because the sidewalk was crowded

On a one way check to work in the morning, I have gotten as high as 37mpg aveage for the 33 mile trip at 60-65 mph. I can hit 40mpg peaks

 

40mpg in the 55mph range is no problem in my SS on a warm day with no wind and no sustained low angle inclines. I have teh 5 speed and I believe it is much eaiser. I did a 37.3 mpg trip from akron canton airport to mohican forest last summer. Its quite hilly near mohican btw, and i did 60-62 in the flats. The 2.2l should get 3mpg-ish better on the highway than my 2.0....I also did this drive on 87 octane...lol