F-16C

I bought my 2011 2.2 automatic last weekend. Filled it up Monday morning and drove to work all week. 85% freeway at 65-70mph. Here is what the outcome was:

170 miles
6.3 gallons used
Shell 87 octang
Tires set at 30 pis cold
26.9 MPG

Info center told me 24mpg ave. Do not know how far off the speedo is but will compare it to the GPS this week. If I set the HHR at 65MPH it tells me 31-33MPG. So far I like the mileage, better then the old Ranger ever got.

IMPALADAKID

Very good numbers. I push the PSI to 32psi, and keep the average fuel economy setting on the DIC viewable. This helps keep me aware of my right foot. I average 26.1 per tank full 50/50 driving. I also do not run regular. I only run super. I do have a 2.4 and not the 2.2. My 2.2 in my panel with regular got about the same, and I did not watch my foot in that one.

F-16C

Thanks, I am coming off motorcycles after 30 years so I am use to seeing MPG's in the mid 40's. But on the other end my job for for 25 years as a jet engine test cell supervisor for the Air Guard. I saw numbers in in the 55,000lbs per hour range. So I guess I will be happy with HHR's MPG.

sleeper

F-16C- I can relate, my bikes run in high 40's for mpg.

Aren't the 16" tires supposed to run 32 psi cold ? That 2 psi increase will help a lil bit..

My 2.4 is averaging over 30mpg @ 70 mph.. (plus my tires are a bit taller than stock).. But speed-O is now more accurate..

F-16C

Sleeper, my tag on the doorjam GM put on it says 30 front and rear. However, mine came with almost new rubber and they say on the sidewall 35psi. Not psi cold. I will have to look into it but I may try 33 for a tank and see what happens. I keep track of all my fillups from the first to the last so over time we will see. I log the following: tire pressure, season outside air temps and conditions, miles driven, gallons used, price per gal, price per fillup. I took one of the jet engine trim sheets and reworked it for tracking fuel mileage. I like this thread you guys made here. I thought I was the only one that kept track of things like this.

B.Diggity

I run my tires at 34, and can average... 23mpg lol. Mines mtx. Some short trips i get 25-29mpg. But the SS is hard to drive correctly..

IgottaWoody

beware..when calculating from the odo..that alot of these cars are running 'up to' 3 mph slower then indicated...bump it against your GPS and you'll see..so your odo calc will be off, to the good, that is indicating a higher mpg then actual....so your DIC may be more accurate then you think.

sleeper

The doorjam is what is called for stock.. I thought it was 32 psi for 16" tires..

My 17"ers call for 35 psi cold.. Since I up-sized to 225/50/17, I run a 36 psi cold & that seems just right for mine.

F-16C

I upped the pressures to 33 today during a day of detailing the HHR. Took it for a drive to get dinner and it drives a tad stiff but a lot less rolling resistance. Easier to steer as well. Found the TPM is right on the money with my tire guage.

sleeper

If the 33 seems a bit too still, 32 may be just the ticket..

My tire gage & TPM are about 2 psi different.. O-well..