just got here, some questions
 

hey guys, just got here, love the forum

I have a solstice gxp, standard transmission, I bought the car for the performance but I also love pushing the envelope in the other direction as well

doing nothing special, setting my cruise control to 62 mph I get 39.5 miles to the gallon over 300 miles of hilly terrain

this is without turning the engine off or doing anything special except I do my best not to hit the brakes

here's the question though;

when I turn off the engine my odometer stops recording so it's impossible to get an acurate read unless I leave the ignition on

doesn't leaving the ignition on do something to the electrionic ignition?

I would rather not leave the ignition on but if you guys tell me there is no harm done that will make me feel better

here's and interesting example of an experience of mine that is counter intuitive;

when I go down a certain road with very steep hills and valleys I get about 50 mpg (coasting without turning the engine off)

I get the same mpg when I go in the other direction so it's not a downhill thing

I don't understand how going up and down hills gets me better gas mileage then going flat even though I coast, this is a counter intuitive result

here's another question;

I read on the forum there are devices that give real time fuel economy...mine only gives overall average and I have to zero out the readout o get real time...this makes it hard to see where and how I get best results real time

what program do you guys use?

anyway, great to see people that enjoy this perameter of performance like I do

I have never had any problems with leaving the car in the on position, you need to so your steering won't lock!

Sometimes hilly terrain is better, use more on the way up but less on the way down and you get a net benefit. *shrug*

www.scanguage.com

Welcome to the site!

Going up hill the car runs at a higher efficiency than it does on a flat road.

This is a weak analogy, so don't stretch it too far. If you had to move 10 cinder blocks 100 yards, would you rather
1- carry them up a flight of stairs, put them and yourself in a wagon, and ride the wagon down a long ramp to the end of the 100 yard course

OR

2- put them in the wagon and pull that wagon 100 yards.

I'd rather carry them up the stairs. I'm more efficient at the higher output.

But that's just me.

I drive flat for about 70 miles EACH way daily. Once I decided to take the hilly route for a couple days to compare traffic patterns/ect and noticed that I got better gas mileage even though the traffic was not much different. I guessed thats it was prob due to the hills (the hilly route is prob about 40 miles, so the commute only differs during that hilly 40 mile part). Anyway I figured that while going uphill I stored potential energy and then just coasted on the downhill portion. So Im only on the pedal for the way UP the hill and never touch the petal during the downhill portion. maybe using your gas for HALF your ride is what gets you better mileage. ALSO, I try to build up speed SLOWLY while going downhill ( I just press a little bit towards the bottom of the hill since gravity speeds me up almost to the speed I want) I then use my momentum to try to make it to the top while using as little gas as possible and maintaining a reasonable speed. If no one is behind me then I dont care about speed. As long as I make it to the top Im happy.
Hope this helps in explaining why mileage is better on hills. Your using momentum from the downhill portion (which required no gas) to go up a hill with less gas. So your only gasing HALF the ride and even less since your momentum acrries you at least half of the way BACK up the hills

you already figured out one of our proven ways off getting mileage. does the hilly route have slower speed limits? that might be a factor also

I don't get it though...you can't get more out then you put in, if you expend x energy going up you should regain less energy going down

given this scenario, that the engine runs more efficient under load thenm no laod it would make sense a jack rabbit a bit (of course deminishing returns and we would have to see what best excelleration would indicate as far as efficiency) and then coast would get more mileage then a slow start and steady speed.

that's counter intuitive but there it is...it's not a mpg thing either because my car gets better mileae in 5th doing 62 then it gets at any other speed

though to be fair, if I am going less then 30 and coast to stops and turns I get better mileage over all then a steady speed limit so I guess it's true, the car under load is more efficient then the car is with no load

counter intuitive but there it is.

anyway, this engine delivers 260 hp, 260 lbs of torque, does just a bit over 5 seconds 0-60, it is a rocket yet it is so efficient if I don't get rough it is unbelievable to me

so, you guys are saying turning the engine off causes no damage to the the points in the electronic ignition?

there are points in electronic ignition though most people think there are not

hey...here's another great thing about this car;

I get quite a few braking oportunities then you guys indicate is normal/..AI never counted but it's a rare case I don't have breaks.

yeah i always flip mine back into the on positon it has never done anything wrong to it. the main thing in eoc is the tranny wear on autos, but i dont think you have a auto so your fine.

I believe the ignition on thing is from the old point days. Iv done it to my car, but not really enough to make a difference. I do very little EOC

there are points on electronic ignition too they just need less attention then on a mechanical ignition

well, I found my answer here

The reason it works is that when you are pushing the engine harder, you might get up to 30% efficiency, while at low loads you are at 20-something percent, if that.

yup, that looks like it's correct as I saw from kps's graph

I pretty much traveled at the same speeds YET realized better mpg on the hilly road. On 95 I traveled from 65-80 and prob averaged in the mid to low 70s. On the hill it was prety much the same average but my range was more like from 50-85, with the 50 being near the TOP of a hill going up and 85 being near the bottom going downhill. But my averages were about the same. The distance was pretty much the same as well. One route is about 1 mile longer than the other, but that shouldnt matter when actually measuring gas mileage. Thats taken into account already when you measure gas mileage.

In any case, my hilly route produced better mpg. It MIGHT be because I was practing low-level P&G (pulse and glide)by trying to make it up hills with momentum (essentially gliding), pulsing up the last portion of the hill and coasting to a fast speed down the hill. At that time I hadnt even heard of Pulse and Glide

Welcome to GasSavers:

The phenomenon you are describing does have some validity, I think, but it is pretty counter intuitive. I had one trip where I went up the hill in 5th, with probably about 1/4 throttle. I was not able to go fast, but I just wanted to try steady. Coming back, I did EOC about 80% of the way back. I was pretty amazed at the mileage I seemed to get.

I removed the steering lock from my car, because one of the issues I was not comfortable with was the possibility of turning my ignition switch to a point where the steering lock engaged. On your car, since the odometer is electronic, you need to have the switch on, but with the engine not running, in order for it to operate. I don't think their is anything you can damage, or at least I haven't heard of any and if their was, I think someone here would have said something.

On your brakes, they have power assist, which operates off of the vacume from the engine running. With the engine off it will operate once or maybe twice and then you no longer have power assist. Technically you still have braking, but depending on the car it can vary from a little stiffer to feels like it's impossible to brake. You need to be aware of how that feals, if your going to do EOC and you need to be comfortable that you can still brake and steer the car, with no assist.

If your car is newer than 98, you can get a scangauge, which will give you a number of additional options, in terms of information. You still have to leave the ignition on, for it to work because it gets all of it's input from the ECU, whether the engine is running or not. If your car is older than 98, you can get a Super MID controller.

Good Luck!

What about 98 cars as in my 98 Camry LE 4cyl 2.2
And how much do these scan thingys cost????

Actually it will work on any OBDII cars, all 1996 and newer.

You will hurt nothing by leaving your ignition on as you coast. There is nothing in your solstice that remotely resembles points. Ignition is achived by a relucter wheel on your crank and cams, signial is sent directly the ECM and then to the coils. When doing anti theft relearning on GM cars you have to leave the ignition on for 10 min. than 1 min. off, 3 times to relearn. So if that won't hurt it what you do won't Lots of techs. leave the radios on for hrs. with ign. on. So enjoy yourself and coast!

thanx minic6, preciate it

now as far as that scanguage

I read the website and for the life of me it doesn't look like it gives real time gas mileage it gives a trip mileage

I have that already, I need something that gives me instantaneous mileage so I can control mpg real time

I can zero out my trip mileage and get a pretty good realtime but it's not practical to keep zeroing out the readout

ruins the wholle affect

perris -

You can observe up to but no more than 4 instantaneous data points at once, and instant MPG is one of them :

Attachment 535

CarloSW2

thanx for the info,will now be happy to purchase