I drive about 11 miles each way to/from work all on one surface street. This road is primarilly flat, 2-3 lanes per direction, with speed limits of 40-45 posted MPH (I say posted because AZ tollerates up to 11 MPH over the posted limit) and I drive it at 4:30pm. Since getting my HHR LS back in October I have always seen 23-24 mpg in the city (I drive 99.9% city) and have been happy with that since my last vehicle got less then 15mpg. Today I deceided to try some hyper miling tecniques and so I reset the instant MPG and watched as it started to show in the 40's. I only got to drive about 8 miles this way so far and I have to admit the traffic conditions and light timing really were in my favor today. I think I sat at only 3 lights and one was for only 15 or so seconds of complete stop.

The things I did today were to put it in neutral the very moment the light ahead would turn red and cost towards the light which allowed me to avoid stopping all together for the most of my drive. Also I would put it in neutral and cost whenever a slower car would come into my lane ahead of me. I would then cost until they either sped up or I dropped below their rate of speed then I would put it back in 5th and barely apply the gas if even applying it. When I did have to accellerate I would shift around 1500 - 2000 rpm. These three things are all I did differently then before and I was seeing up to 43 MPG. When I sat at those three lights though I could watch the MPG drop fast. When I turned the car off to go into work, I was at 36.3 MPG due to the longer two of those three stops was within the last mile of my drive and then speedbump city in my parking lot. I hope to be able to continue this next work week.

What I am wondering now is how I can maximize my MPG on my way home from work at 5am when there is no one else on the road and coasting will be far less af a need and more of a should I do it now or how about now lol type of thing. I am also curious how much more I can gain if I were to turn off the engine at stop lights and when I am coasting for a longer period of time. Please give me some tips, ideas, findings on this pretty please.

All in all I know what I got today was on the high side for my work route but if I can manage to maintain atleast 30MPG in town I will be a very happy camper .



FWIW car has 65k, oil is Valvoline Full Synthetic 1k old but car says 76% already :, fuel is 87 octane, tires @33psi

 

shutting off the car and restarting it is going to waste gas and put unneeded strain on the battery. tried this onceand found leaving it idle at stop lights was more fuel efficient. stopping for long periods of time is definetly a time when you shoud shut er down. cruising around in fifth in the early am will help your gas mileage. the starting and stopping is what really wastes fuel just when you need to stop coast it to the light. and coast it as you come up to a turn and such. i coast it any time i will be using the brakes. puts slightly more wear and tear on the brakes but pads are deff cheaper tha the fuel im saving. ps on your oil city driving shortens the life span of the oil.

 

Although I have an auto HHR, I do a lot of coasting up to a red light (not in neutral). With a light foot when acelerating, my HHR rarely gets over 2500 rpm before it shifts to a higher gear. I had a max mpg of 38 mpg over a 260 mile route a couple of times. It is a route with lots of 55mph speed limit over "back" roads. My 2.4L '06 LT1 has averaged 30.6 mpg since I bought it new and I now have 91K+ miles on the car. BTW I still have the original brakes and they are still good.

 

When I got off work last Saturday morning I started the car but had a coworker stop me and talk to me for about 5 minutes. The car was left idling during that time and took my instant MPG down from that 36.3 down to 27.5. Then the long slow drive out of the parking lot only to sit at the light for a bit, took it down even further. When I finally got going on the main road I was down to 25 and change showing on the DIC. By the time I got home (11 miles) I had got it back up to 29 and change. Over the coarse of my weekend I drove maybe another 60 miles or so and was able to keep it around the 30mpg mark. I know I said I would be happy with that amount but it took a lot of work just to keep it there so it was a bit frustrating at times. Again this is 100% city driving.

What I have decided to do is to reset it right before I start the car to leave for work on the first day of each work week while I test a few different methods for sipping gas. Today was my first worknight of this week so I reset the DIC again and started a new week of tracking. I should note that last week when I reset the DIC I was coasting and that gave me a 100MPG head start which gave me those false numbers from last week. That is why I am testing for a week at a time and why I reset the DIC with the car OFF.

So today was a normal/average drive in to work with me having to stop at almost every light. I tried rolling as much as possible with even trying to brake fast farther back so that I could roll slowly to the light. Unfortuneately the lights here are pretty long and I was seeming to get to them just shorly after they turned red. Todays number when I parked the car at work was 31.1 so not too bad. It seemed easier to keep it near or above 30 on this drive then the past 4 days of driving. We shall see in the am if I can keep it at 30+ or if I can even get it to go higher. I only have 11 miles to work with but I noticed that on the way in the last few miles I was seeing a consistant increase in the MPG's. Hopefully I can continue that steady increase on the way home.

As for turning off the engine, it seems to be a common suggestion in most info on Hyper Miling. I know that when I sit there idling I can see a steady drop in the MPG's. Now if the DIC has not been reset in some time then you would have sooooo many data points that the few that add up while sitting idle at a stop light are not going to show on your DIC. With reseting it frequently you will see a dramatic drop every time you sit while idling. Of coarse if the light is about to change for me I would not want to turn off the engine but like I stated above these lights here are quite long and if you get to one right when it turns red you will be sitting for 2-3 minutes so you will waste a lot of gas. A lot more then restarting the car I would think especially with todays cars.

So with that said I intend on testing this next week and comparing the data to see if I get better or worse results. I have even considered reseting the DIC each day and tracking that way as well as weekly but for now I am going to stick with weekly.