Clevelandhhrss

I re-read my post and it came off a bit "short". I was in a hurry. Sorry. What i meant was that I have been trying more aggresive techniques to improve city mileage. I have reached the point where i TRULY get annoyed if I do not get 450 miles out of 14.25 gallons. Or 31.5mpg overall. I do a lot more city driving now (no more work and/or pleaseure long trips ), and I liked when my dic saids 32.3 (33 hand calculated) after 450 miles. Now since my avg mph has decreased from 43 or 44 down to 32-34, it take more effort to get 31.5-33 mpg. I know that my hhr SS 5 speed will get 36mpg on a flat dry smooth road with 87 octane windows/sunroof up or down, no a/c, 34+ tire pressure at 60mph on brainless cruise control. So to get 38 I would need to play '"rollercoaster" with each and every hill I encounter. That means, set cruise at 50, drive at 60 (yes this takes patience and skill) and very slightly accelerate on the downs in preperation for the ups, and glide the ups until the cruise kicks in right at the crest of the hill. If you are able to "read the road elevations" beforehand, you can ever so slightly gain mpg above 36 by doing the rollercoaster. Yes this is not what I would do if i wanted to get someplace fast, and no i would not do this on a 2 lane highway. I stay in the slow lane, or one over to let the semi's by. I can get 38 this way over longer highway trips. It becomes second nature after a while. I am an ex-amature mountain bike racer, so I am used to reading even the slightest grades and road elevations. My coefficient of drag on the bike is around 0.90 versus the hhr's 0.354 so I am keenly aware of the effects of wind, rain, rough roads and terrain on mileage.

My problem comes in the city, where I cannot predict all lights, stops, stupid drivers...etc. So I have been "pulse and gliding" where I can. The hhr ss i think saids 22 on the sticker. I have been getting around 31 completely in the city with alot of stops, but fairly short lights. As I get better, or simply take the same roads day in and day out, I should get to 33 or more. Certain routes (hilly in a good way) would yield 35 or more. I'm still learning.

balogh

Illinois, being a flat state, is great for hypermiling. We drive on back roads about 45-50 mph and get anywhere from 35-40 mpg.. our average highway/city mileage is now up to around 28mpg (drove in chicago & st. louis). If we drive from champaign to st. louis, we average 33mpg going 70mph with cruise control and better if we drop down to 65 and shut off the air conditioner. we have had our car 1 month and love it we already have over 2500 miles on it.

The Curly 1

Look I understand "Hypermiling" to a certain extent after all I bought my HHR for the sole reason of gas mileage. My one ton dually Chevy 454 gets terrible gas mileage. I have done a little experimenting and "Drafting" does save gase mileage big time. Once I got stuck in a bad cold front on my motorcycle I got in and drafted a Semi to keep from freezing and make it home. Drafting for gas mileage or what ever is not smart but it really does make a huge difference.

My HHR gets about 28 MPG on the highway at 80 MPH, 32 at 70 and 36 at 60 MPH. I usually drive 70 but do try not to eccelerate and stop too quickly to get the best I can from it and still get there. Drafting is probably good for 10 MPG more but sooner or later will cause a problem.

One thing that pisses me off worse than anything is people going 41 MPH in the fast lane. Sure they get better gas mileage but I sure hope they signed their organ donor cards. They are an accident waiting to happen. I passed an old lady today and she was going LESS than 45 on the highway in the fast lane, I honked my horn when I finally got around her and she flipped me off! Stupid old lady probably thinks she is doing her part for the environment. No problem just do it in the slow lane.

There are some good tips here to improve mileage.
What I am curious about is anything mechanical such as exhaust, air filter, chip etc that will give any definative improvments. Bruce

Clevelandhhrss

I think tunes are good for a few mpg, maybe a CAintake/header/exhaust, but i just focus on driving. I have begun seriously hypermiling this past week, and 38+ is no prob on the highway, and 33+ no prob in the city. It just takes a little concentration, but it is becoming second nature...lol

So far this week, 34mph avg, 33.7 mpg about 100 miles. Not bad for such a low avg speed.