35 mpg at 65 mph !!! the 31.69 was without even trying , average from a 370 mile trip. i tryed using the 93 octane before. i got a small gain , but not enough to justify the cost. i got 08 2.4 auto. i thought i'd try again since gas price dropped slightly and i got a discount from Sheets gas station. also since i took off the oem cold air "wooly worm" tube , added the dynomax straight thru muffler, and added the 0-20w oil....30.5 mpg at 75 mph. i will continue to test it a little more. i think it may be worth the extra cost of the 93 octane now since it seems as the combination of the mods and the 93 oct have given better results than just the 93oct before the mods. it may still not be cost effective. but it is amazing me.

35 mpg at 65 mph !!! the 31.69 was without even trying , average from a 370 mile trip. i tryed using the 93 octane before. i got a small gain , but not enough to justify the cost. i got 08 2.4 auto. i thought i'd try again since gas price dropped slightly and i got a discount from Sheets gas station. also since i took off the oem cold air "wooly worm" tube , added the dynomax straight thru muffler, and added the 0-20w oil....30.5 mpg at 75 mph. i will continue to test it a little more. i think it may be worth the extra cost of the 93 octane now since it seems as the combination of the mods and the 93 oct have given better results than just the 93oct before the mods. it may still not be cost effective. but it is amazing me.

I recognized a little better mileage than that AND I didn't have any engine mods. It was on a 8000 mile trip. There's a thread about it, if you're interested. My findings, after driving the exact same route in each direction (for those that need help....4000 each way) AND using the same driving principals, was the price of premium fuel is a break even on mileage......about 8%, if I remember correctly. I do continue to use premium, however. I, in everyday use, put very little mileage on my cars. About 3000-4000 per year, not counting LONG trips. The difference in price, is minimal at this point.....about $20 per year.

YRMBD

What did you replace the intake tube with? I've been looking to get rid of the OEM piece o crap.

I recognized a little better mileage than that AND I didn't have any engine mods. It was on a 8000 mile trip. There's a thread about it, if you're interested. My findings, after driving the exact same route in each direction (for those that need help....4000 each way) AND using the same driving principals, was the price of premium fuel is a break even on mileage......about 8%, if I remember correctly. I do continue to use premium, however. I, in everyday use, put very little mileage on my cars. About 3000-4000 per year, not counting LONG trips. The difference in price, is minimal at this point.....about $20 per year.

YRMBD

thats great........i was only getting 27mpg on a good day before i made any mods. and i was trying my best to improve , cuz of my 275mile a day route, 6 days a week........i've seen others get better and worse mpg than i do. there are lots and many variables for what makes the mpg. i think most idifferences are due to drivers style, speed, and psi in tires. what is $20/yr to you would mean $40/month for me , at 85,800 miles/year. or more. i'm getting 93 oct for 2.11 9/10 now. reg is 1.91. even if i get it down to 8 gal/day , thats , $41.60 dif in price/month. anyone know where i can get a hyrogen fueled car?:roll:

My experience has been about the same as Snoopy's. I get 31 on the freeway using 93 without even trying hard. No mods, and we have to use E-10 here. When I tried 87 octane, I got about 29. As has been said, the cost savings is pretty much a wash. When it was $4.15 a gallon, I did the math and found I was saving about $100 a year by using 93. Now its probably closer to $25 a year. I keep using 93 because it runs a bit smoother and there is a notable power difference at freeway speeds.

What did you replace the intake tube with? I've been looking to get rid of the OEM piece o crap.

i haven't put anything in it's place yet. some say and or think that it is not good because they think or say that it is sucking hot air. i think that the only time it will be sucking hot air is when it is sitting still. also if you look at some of the $250+ cais you will notice that they do not go thru the firewall or fenderwell cold air hole. if you sit a round filter in front of that hole as most of the aftermarket cais do , it is still sucking "hot" air from the engine bay.....i would think that even a radiator hose would be better than the wooly worm , if you could find one that size. the oem wooly hose i took off mine was partially collapsed , more oval than round.... if i can find the time and energy i would like to make a intake from spectre brand cai parts from the napa store.they have a universal maf piece. the napa guy said it is for imports , but i think it can be made to work. also to fabricate a box for the filter to sit in. simular to k&n , gm performace , and others. but instead of it sitting on top of the engine , have it sitting next to the fenderwell cold air hole and sealed to the fenderwell , not just sitting in front of it.....anyhoo , it seems to be working good as is , just by simply removing the wooly worm.

Just FYI, I found a Supplement page in my owners manual that reads:

"If the vehicle has the 2.4L L4 engine (VIN Code V) or the 2.0L L4 engine (VIN Code X), use premium unleaded gasoline with a posted octane of 91 or higher. You can also use regular unleaded gasoline rated at 87 octane or higher, but the vehicle's acceleration could be slightly reduced, and you might notice a slight audible knocking noise commonly referred to as spark knock."

Sounds to me like a minimum of "mid range" octane fuel would be recommended and for as little as I drive mine, I'll be filling up with premium from now on.

I don't care if people don't believe me, but I SWEAR that I drove from Frankenmuth to Petoskey (about a 200 mile drive) going 60 on the expressway, and I got slightly over 40 mpg in my Lumina. I added the numbers multiple times, and it still came out to that.

Say what you want, but I still know that you get better MPG with 93 octane. Now that it's summer and I have the truck out, I'll probably start putting it in the HHR. (Only because I fill up with the truck and get gas cans, and I run premium in the truck)

I have an '06 1LT automatic, and get 25 mpg around town and 29 hwy on 87 octaine. No mods on the car. Seems like I read somewhere that higher octaine would not be good for my type of HHR, however if premium gas would be beneficial on the hwy for long trips, I certainly would want to try it. Any suggestions?

I have an '06 1LT automatic, and get 25 mpg around town and 29 hwy on 87 octaine. No mods on the car. Seems like I read somewhere that higher octaine would not be good for my type of HHR, however if premium gas would be beneficial on the hwy for long trips, I certainly would want to try it. Any suggestions?

A 1LT can be either a 2.2 or a 2.4. I have a 2.4 1 LT and it is recomended to run on 91 octane. 2.2's should run well on 87 octane.

So do you have a 2.2 or a 2.4?

I have an '06 1LT automatic, and get 25 mpg around town and 29 hwy on 87 octaine. No mods on the car. Seems like I read somewhere that higher octaine would not be good for my type of HHR, however if premium gas would be beneficial on the hwy for long trips, I certainly would want to try it. Any suggestions?

Premium wouldn't hurt it, that's for sure.

well.......... i have a 2.4 have used 87 oct and just got back from springfield, and decided to drive 65 and under...... got 30.7 per gallon......... i have no modes, straight factory, and 87 oct.,

but this will be once in long while due to thats not my normal drive.....
kc to memphis 87 oct 27.6 at avg 85 with air

these were not dic numbers this was manual caculations with my fancy texas calculator. :D

My last trip (700miles), all freeway, I easily got 32.5. 4 adults in the car, winter, cruise on the whole way, averaged about 70 mph. 2.2, no mods, regular gas, 0W30 Mobil 1.

Summer trips with only 2 in the car I can easily get 33.5, I've gotten 34.5 with good winds both ways.

the results i posted are not from getting on the hwy and hitting the reset. they are from an average and or figured on paper after each fillup. i did reset today after fillup. 14 gallons this time , and i'm also trying 89 octane now to see how it results. 40+ miles since fillup and reset , 37mpg , but this on "country/curvy/hilly roads w/only a few stops , at 45-65 mph..... oh , i was getting 7mph at 115mph before the reset. but i didn't set the cruise control ;), also there were no houses to hit , and i was not racing:p:.....i really think that something is a little "off" on my hhr -besides me:nuts:- , after seeing so many get better mpg , unless they travel where the terrain is much different...but i've also seen a few list that they are getting much less...i think i need to find a local tuner...has anyone tried a tune from their local shop , for mpg ???

i really think that something is a little "off" on my hhr -besides me:nuts:- , after seeing so many get better mpg , unless they travel where the terrain is much different...but i've also seen a few list that they are getting much less...i think i need to find a local tuner...has anyone tried a tune from their local shop , for mpg ???

I agree... I don't get how someone can get 33mpg at 70 with the cruise, and I can't! (I'm not saying I don't believe them, because that sounds about right.) It's just I don't get why I go 60 with the cruise and can only get 32mpg. I know it's not my driving...that's for sure!

Hey Everyone! Thanks for all of the advice:bow: your input has been quite helpful!

After looking at al the various MPG's I'm glad I have an SS,,,,, My last trip got me 31.5 with a load and quite a variale terrain and I generally see 28 locally.....only difference being..Ive go wow power! and this is with the stage kit..though I did see about the same before and running 87 gas. I could never complain about a 2.0 that feels like a v8....!!

The high mpg's are pretty much fill up, hit the reset, then hit the freeway. I still get easily 25-27 in combo city driving. A bit of freeway, surface streets, etc. Still as good or better than a lot of vehicles out there,and better than anything else with this kind of interior room. Plus it's just a great vehicle to drive and look at.....wish I could afford another for myself.

Just wanted to say that I pumped in 14.6 gallons of 93 octane yesterday and although I have nothing to prove it, I can feel a difference in the performance. Before, I had a strange issue that could best be described as a "flat spot" in throttle response between about 40 and 60 where I would push on the accelerator slightly to pick up a little speed and the response was sluggish so I'd push a little more and the engine would "surge" or respond disproportionate to the last throttle adjustment.

Now I don't notice that with the 93 octane.

I wonder if the computers that control the valve timing and such react differently with the higher octane fuel? Whatever it is, I'm sticking with the premium gas.

i normally use between 91 and 93 octane, which ever the highest they have, and recently went on a 5 hour road trip, 2.5 hours there and back, and was gettin between 32 and 33 mpg. i have a stock 2lt with a 2.4 liter and no mods.

I don't know where people find 91 octane. In Florida its 87,89 or 93. I've been running 87 in my 1LT with a 2.4 auto and have averaged 30.3 mpg since he car was new, some 48,000 miles of driving. On the highway I'll get 32-33 mpg with cruise at 70 mph. Around town only my mileage will drop to 27 mpg.

Your lucky you have 93 octane. Lots of places in the country have 91 octane as the high test or as a friend of mine in Colorado calls it Squirrel Piss Fuel.

It was on a 8000 mile trip.


:eek: WTF? Did you drive to Tierra Del Fuego and back or something?

:lol::lol:

Almost....:D

Arizona (home) to Indiana.
Indiana to Michigan
Michigan to Illinois/Missouri (man, right on Ol' Man River....really a nice place)

Illinois to N. Dakota
N. Dakota to S. Dakota
S. Dakota to Wyoming
Wyoming to Montana
Montana to N. Mexico
N. Mexico to Californicate
Californicate to Home

I think it was about 31 days.:nuts::steering:

But now that you mention it...my mistake. I confused the mileage from 2 different trips (although the MPG was very similar). The 8000+ miles was the year before and as indiated above. The actual MPG "test" was last year and that was about 4400 miles....Arizona to Indiana to Arizona.

Wow...quite a road trip!!! If you still had factory warranty, it's probably gone now, huh?!?! :nuts:

Wow...quite a road trip!!! If you still had factory warranty, it's probably gone now, huh?!?! :nuts:

Actually it just expired.....on time.......36 months. I only have about 26000 miles on the HHR. It's for trips and "grocery" getting. Also have 2 other vehicles so the mileage is split up.......my wife is the mileage hound however. And we will be using her car for the big trip next month.

Just came back from dropping a friend off at the airport and checked my gas milage on the return trip.
93 octane, 70 mph average, 30 mile trip, 29.7 avg mpg... no cruise... with A/C... only 873 miles on the odometer

After slugging around in Jeep for the last 14 years I'm pretty pleased.:thumb:

Hmmm ... I always seem to do very well with my 2.2 on good ol' 87 octane from Home Depot Fuel. Here's the pic to prove my point:
http://i707.photobucket.com/albums/ww79/timhenard/fuel36.jpg

03/08/09 heading west on I-24, returning home after a weekend in Alabama. 71 mph, cruise set.

So then why does my 2.2L running 87 octane only get 29 mpg going 70 with the cruise? I DON'T GET IT!?

every car is different. if i can set the cruise at 68-69 ill easily get 34. as i go faster it drops off

So then why does my 2.2L running 87 octane only get 29 mpg going 70 with the cruise? I DON'T GET IT!?

Its the wax. A well waxed slippery car gets better mileage.

Its the wax. A well waxed slippery car gets better mileage.

:lol::lol::lol: Then I should be getting 80mpg!!!!:lol::lol:

I've found with my HHR that the "sweet" spot is 65mph. Any faster and I drop from 31mpg to under 30.

Guess I'm lucky. I average 29.5 during the week in my daily commute (23 miles each way, combination of city street and interstate, occasional stop-and-go in the morning, but consistently half the commute home is stop-and-go). Not bad from what I see others getting.

I have a 2007 2LT HHR (2.4L engine). To increase performance AND gas mileage, I replaced the factory air intake with a CGS/K&N air intake system. (took all of 30 minutes to install) and a CGS muffler. Then I re-set the ECM. I have better performance (than when the vehicle was new) and achieve 41.5 MPG @ 55 MPH (level ground) and 36.5 MPG (again @ 55 MPH) on the hilly freeways of Maryland.

Fuel: Supreme (91 octane)

Tires: Michelin Pilot AS

Oil: Mobil 1

Any witnesses to this stunning feat of new math?

Don't think those are averages....IVE seen steady 40's under certain conditions on the DIC...

The best I have seen was a 200 mile trip from Medina to Dayton. Set the cruise at 70, windows up with no air (cool day), and the computer said 31.6 mpg. I filled up and calculated it by hand, and it actually got 34.3. Around town it seems to be getting 24-26mpg. all on 89 octane gas. My trip computer seems to consistantly register 1-2 mpg less than it actually is getting.

Hmm...for some reason I seemed to do really good yesterday!

I drove a total of 313.6 miles, with a DIC reading of 30.2. That includes some city driving in Hillsdale. Going down I drove 146.2 miles at 70mph most of the way, and got 31.1 according to the DIC. All expressway driving was cruise set at 70mph, and country driving was between 55mph-60mph.

I will fill up tomorrow or the next day, and I will calculate by hand to see how accurate the DIC is...

Hmm...for some reason I seemed to do really good yesterday!

I drove a total of 313.6 miles, with a DIC reading of 30.2. That includes some city driving in Hillsdale. Going down I drove 146.2 miles at 70mph most of the way, and got 31.1 according to the DIC. All expressway driving was cruise set at 70mph, and country driving was between 55mph-60mph.

I will fill up tomorrow or the next day, and I will calculate by hand to see how accurate the DIC is...

AC on or off?

On the way down, it was on the lowest setting...most of the driving in Hillsdale was on full blast, and on the way home again the lowest setting... So it was on all day.

thats great........i was only getting 27mpg on a good day before i made any mods. and i was trying my best to improve , cuz of my 275mile a day route, 6 days a week........i've seen others get better and worse mpg than i do. there are lots and many variables for what makes the mpg. i think most idifferences are due to drivers style, speed, and psi in tires. what is $20/yr to you would mean $40/month for me , at 85,800 miles/year. or more. i'm getting 93 oct for 2.11 9/10 now. reg is 1.91. even if i get it down to 8 gal/day , thats , $41.60 dif in price/month. anyone know where i can get a hyrogen fueled car?:roll:

I would simply add a HAFC system to your baby and you'll see fantastic results. I have gotten a gain of just over 50% (30 MPG @ 70 to 46-48 MPG @ 80MPH!).
You could feasibly add a system for about $1,000.00 that could be transferred to another car at a later date. If you cannot afford, try these (free to cheap) fixes: Get rid of parasitic losses. Inflate your tires +15% to 37-39 PSI. Amsoil (I sell it too) 0W30 will gain you another 5% from reduced friction and also saves on start up damages from higher viscosity oil.
With the mileage you do, I would suspect your savings to pay for a system in no time. Also, the Federal Tax incentive is up to $2,500.00, so theoretically, it could be free. :thumb:

I would simply add a HAFC system to your baby and you'll see fantastic results.

Allow me to be the first to call BS on this. These things DO NOT WORK. If they did, every auto maker on the planet would be putting them in their cars and there would be a facility on every street corner retrofitting them to existing vehicles.

We're not that stupid.

So, I filled up today (of course, AFTER gas went up another 20 cents...) and going by old school pen and paper, I got 28.4mpg...and the DIC said 30.2...

Don't really know why it's off that much, but 28 still isn't bad considering that included some city driving too...

Gas mileage is an interesting thing. I rented an '07 2.2 Cobalt and drove it on a 2,000 mile round-trip to Baton Rouge. Going down the little car got 37 mpg "ave mileage" while locked on cruise for 16 hours. Coming back the "ave mileage" readout said 35. Same speed, same gas, same trip. The reading was confirmed by my written notes of gas burned. On another trip to Baton Rouge a little later I ended up with a Civic. The Civic got 30.5, was noisier and much slower.

The Cobalt mileage, comfort, and power caught my attention, and I planned on eventually replacing my old car with a Cobalt. That was the plan until I noted the HHR was on the same platform, and sat in one. In my humble opinion, the seats are much better in an HHR. I love my new HHR, but do miss having a trunk.

Why did that rental Cobalt vary 2 mpg on the same trip? Who knows?

God Bless, Marc

I agree Woody. Car manufacturers are under the gun to improve fleet gas mileage, and will be using anything they can to get an improvement. The last time someone tried to sell us something like an HAFC system...they were carrying a carpet bag. Heh, heh, heh. I wonder if "snake oil" would improve mileage? ;-) God Bless, Marc

<<<<Quote:
Originally Posted by sfttailpaul
"I would simply add a HAFC system to your baby and you'll see fantastic results."

Allow me to be the first to call BS on this. These things DO NOT WORK. If they did, every auto maker on the planet would be putting them in their cars and there would be a facility on every street corner retrofitting them to existing vehicles.

We're not that stupid.
__________________
Woody
"Beatings will continue until morale improves">>>