Archives

Im taking another stab at this. I haven't been focus on hypermiling for a while now due to some frustration with making progress. Im getting about a 25% improvement in mpg doing what Im doing now, and want to push it up to a 50% improvement in fe. For me this means improving my daily commute from about 31mpg round trip to 40. My car is rated at 20/27 and has awd with a manual tranny. I have a short 11 mile commute with some unavoidable bad spots.

On a good day I might get 32 to 34 round trip if I really push it hard.

So right now I'm reevaluating what Im doing...

I just increased my tires from 50 to 60psi the other day (and no, they haven't popped ) :woot:
I have no hw mods and no scanguage (Im a cheapskate)
I'm using regular 5w30 and the gas has 10% ethanol unfortunately

My commute is 11 miles each way and can be all back roads or half back roads, half highway. Either way the distance is about the same.

I typically do about 30 to 45 in 5th gear ( 1500 to 2000 rpm ) on back roads, and try to keep rpm under 2250 at all times.

I coast nice-on whenever there is a hill and milk it until i get down to about 30 mph
I usually let up on the gas and nice-on shortly before hitting the crest of a hill

I dont rr, go below the speed limit, or fas ( I could be wrong but I don't think there's a big difference between fas and nice-on - correct me if Im wrong )

I'm wondering what it might take to push this to the next level and gain another 10 mpg ?

Do i need to drive 20-25 in the 30pmh zone to pull 40mpg ?

1. On a nice warm day, with tires pressed up, I can hit 30mpg on my way into work nice-on.
2. On a nice warm day, with tires pressed up, I can hit 50+mpg on my way into work FAS.

The higher your idle gph (gallons per hour) consumption is (0.45 with my avenger) the more you'll benefit from FAS. Everyone benefits from fas if a vehicle is capable.

A few comments and I'm sure you will get others. First, the ScangaugeII is almost a necessity to figure out which techniques work for you and which ones do not. If you participate in a group buy here, then you will save a bit of money. Really, I never learned anything until I got my SGII. Otherwise you are shooting in the dark.

With a MT you can easily fas (shut the engine off while in motion) and just put the car back in gear for the bump start. Be sure to practice this under controlled conditions and make sure you can steer without the pwr steering(i.e. big parking lot), and that you get the feel for when to expect the loss of power brakes(about 2 applications). Doesn't seem to cause any harm once one become proficient - counter to what I had originally thought. In addition, the slower you turn your engine, the more efficient. If you can go 25 in the 30 mph zone while in top gear, then that will be more efficient.

It is tough, and can get discouraging when you face the numbers that some of the more experienced folks pull. I know - I've been there. But rememeber that they too had to start somewhere. This is a very supportive site and I'm sure you will find ready help on any question you have.


I have no hw mods and no scanguage (Im a cheapskate)
I'm using regular 5w30 and the gas has 10% ethanol unfortunately

My commute is 11 miles each way and can be all back roads or half back roads, half highway. Either way the distance is about the same.

I typically do about 30 to 45 in 5th gear ( 1500 to 2000 rpm ) on back roads, and try to keep rpm under 2250 at all times.

I coast nice-on whenever there is a hill and milk it until i get down to about 30 mph
I usually let up on the gas and nice-on shortly before hitting the crest of a hill

I dont rr, go below the speed limit, or fas ( I could be wrong but I don't think there's a big difference between fas and nice-on - correct me if Im wrong )

I'm wondering what it might take to push this to the next level and gain another 10 mpg ?

Do i need to drive 20-25 in the 30pmh zone to pull 40mpg ?

Thanks for the advice! I got 38.1 mpg on the way in this morning. Thats about 1.5 mpg better than my best commute .. and it was only 50 degrees out this morning !

Things I did different:

Used fas whenever possible. Felt like the car was off more than it was on.
Allowed the car to slow down to 25 a few times ( got passed .. oh well )
Used the back roads ( which was actually 1mi shorter) instead of the highway
Left for work earlier - less cars on road, less waiting in traffic.

Going to start focusing on getting the pulse right now .. I think this is where Im blowing the fe. Seems many of the fas glides ended with either lower mpg reading or same mpg reading.

Seriously considering getting a sgii when i get my income tax check.

:)

I found that with the car off most of the time I was still getting around 32-34 mpg. This indicated to me that I must be wasting gas on the pulses and when climbing hills - those are the only times I use gas. I found yesterday while experimenting that I was able to pull some very high numbers ( mid 50's and 60's) on some short runs (10 - 15 mi ) which I normally get high 30's on.

Things that made a difference were:

1. Accelerating really, really slowly ( like an old lady in a Lincoln ) - barely touching the gas pedal . Normally I go from 0 to 40 in about 10 or 15 seconds with pulses for p&g a bit faster. This time I'de say I took about twice as long to accelerate (possibly longer).

2. Keeping rpms locked at 1500 when going up hill (regardless of which gear I'm in ) - even up slight inclines. In these cases the engine is still able to accelerate but I'm holding back. ( I think in this case the engine is working more efficiently since its sweating a little (bsfc) )

3. Accelerating only on flat runs and downward slopes - hopefully getting enough momentum to fas and clear the next hill.

4. In one place I took a longer route that had a more gradual downhill slope. This did not use more gas since I fas'ed down. It did however give me a better average.

5. Allowing the speed to drop to 20 if nobody is around, or 25 if someone is behind me.


I tried to reproduce this on this morning's commute but could not. I suspect it was due to several factors.

1. It was 33 degrees colder ( 37deg this morning )

2. I felt rushed/pressured by vehicles behind me - because of this I stepped on the gas a little more and didn't milk it out in some places.

3. Yesterday's runs were on a warmed ( or somewhat warmed ) engine

Worth noting:

At 70 degrees I was able drive a little, then fas down hill getting well over 76mpg after a mile.
Today at 37 degrees I did the same exact downhill fas and got only 50mpg or so.
-- Starting the engine and climbing two tiny hills in each case Is all I did, so that 37 degrees made a huge difference.

Does your Subaru have a turbo? Perhaps before you were spooling up the turbo and with your slower acceleration rates you now are not?

No, no turbo. Just a plain 08 Impreza.
I'll try to reproduce this again tomorrow ( or the next time the temperature is back up around 70 )