which would benefit me more?

[Brian03cav]

trying to decide which would benifit my quest for better economy more. my two options are - -

1. installing cruise control
2. buying a scangauge 2

my car does not have cruise, which i think would help alot with the amount of miles i drive on highway, letting the computer control things. or get the scan gauge so i can monitor things and find out. im not too sure how to go about installing cruise, but i might just call the dealer and find out. if its less then $300 it might be worth it?

what are your inputs? which should i go with?

thanks
Brian

[FastPlastic]

I would suggest the ScanGauge. Nothing makes the foot lighter then watching the MPG's go down. Plus unless you get the older style cruise control (holds the gas steady rather then the speed) you'll see better results without cruise.

But it all depends on if your foot can handle the long drives.

[99metro]

Definitely Scangauge. Cruise Control will only give better economy if you have extreme problems with your right foot! I "almost" doubt you will find any hypermilers here that use cruise control...very inefficient way to save gas.

[Daox]

Scangauge hands down. Applying a few of the driving techniques here will net you better mileage by far than a cruise control can do. For the average driver who doesn't pay attention to anything and speeds normally, yes, a cruise control will help. For someone who knows what they are doing, the cruise control will actually hurt.

[Brian03cav]

wow ok, i remembered seeing something on a site saying that highway mileage could be increased if cruise was used, by a pretty decent percentage. i had my longest straight ride in my car so far yesterday, about 120 miles each way, so 240miles (or 4 hours in one day) of driving. and it was kinda bothering me that i couldnt just say go to this speed and stay there. but i did get good mileage on the trip regardless, so maybe the gauge is the way to go.

this may be a bad question, but is the gauge accurate? i'd really like to see a running average, and instantanieus(sp?) at the same time if possible.

[FastPlastic]

Mine was within .03 gallons and .20 MPG's for the tank when I filled up the first time to calibrate it.

The gauges I normally have up are RPM, Gallons per hour, Instant MPG's and I also have Average MPG's for the current trip.

[Brian03cav]

oh so you can edit what you see on the screen? that would be great. is the calibrating hard? im not too experience with this sort of thing. im about to order one right now after seeing the responses here.

[SVOboy]

Sgii!

[jamesqf]

Originally Posted by Brian03cav

wow ok, i remembered seeing something on a site saying that highway mileage could be increased if cruise was used, by a pretty decent percentage.

Not true, at least if you drive in hills - and I don't remember too many non-hilly places in Pennsylvania :-)

Cruise control tries to hold a steady speed, so what happens on hills is that it will be going along at the set speed on the level, and when it comes to a hill will increase throttle to keep the same speed going up, then back way off on the downside. That's bad for FE.

What you want is to "rollercoaster": speed up before you come to the hill, lose a bit of speed going up, then let gravity speed you up again going down the other side. If you get a ScanGauge, you'll be able to see this in action :-)

[Brian03cav]

made the plunge, ordered the scangauge 2. should be here wensday. cruise would have cost me around $300 if not more anyway, thanks for all the help guys, otherwise i would have gone with the cruise probably.

cant wait to get it and share results.

any tips or things to look out for my first time using it and setting it up?

[azraelswrd]

tips:

When you fill it up, make sure it's around 1/4 of the tank (or less). The first few tanks may be wonky for tank calculations -- for me it overestimated my MPG by a massive degree which is why my fillup adjustment was +12.2%. My last refill the SG was off by +0.1gal so now my adjustment is +13.3%.

If you intend to do any forced autostops or engine-off-coasting, use HYBRID mode but that may not work all the time. The SG prefers the engine running than not to function properly.

Deceleration fuel cutoff (DFCO) is calculated when your engine loop is OPEN, the rpm's are above the cutoff limit plus above the idle throttle position selector*. You know if you have DFCO when your MPG = 9999 or the GPH = 0.00 and most modern fuel-injected vehicles do have it

*idle throttle position selector = when car is idle, the current TPS value

I followed the manual's recommendation and set the "FUEL CUTOFF" value to 14, which is 4 above my idle TPS (10). I note this because I've seen a lot of people confused by this over on CleanMPG so I figure I'd kill the beast before it got loose.

You can make your own customized gauges called Xgauges.

[Brian03cav]

azraelswrd,

so you're saying i should let my tank go to 1/4, then fill up completely, then plug in my sg2? im just trying to understand so i get the best possible results.

i dont plan to turn my car off while driving it, but i have been wondering about the Deceleration fuel cutoff (DFCO) as you called it. does my 2003 cavalier have that? so i should stay in 5th gear when coasting instead of putting the car in neutral? i figured only more expensive cars would have this feature. my car is manual so i was putting it in neutral on long downgrades.

as for the adjustments, did you make those by using the sg2, and keeping track of your mpg the traditional way? then setting the difference in the sg2?

im excited to use it, but nervous im going to mess up the settings. i expect it to arrive on wensday!

[azraelswrd]

Got ahead of myself. Plug in your SG, then fill up the tank but don't make any adjustments for that FIRST TANK. The next time you refill, wait until you have 1/4 left in the tank and then you can make your fillup adjustments. Adjustments at the fillup are based on the ACTUAL amount of fuel I pumped into the tank at that time so no need for traditional tracking.

ex:
I pumped in 8.747 gallons today. I turn on the Scangauge, go to FILLUP and it says I used 8.6 gallons. I then adjust it to agree with the actual fill amount (8.7) and note the adjustment percentage (+13.3%). That's it.


When you first plug in the SG, you need to calibrate your car info such as engine size, tank size, fuel type and car type. The instructions for the installation are pretty clear.

***
Your Cav should have DFCO. What you do will depend on what you need to do -- if you need to stop soon, I'd coast in gear. If you have a downslope or no stops in the near future, neutral is better. This is where having a SG is really useful but it sounds like you already know what you're doing.

***
I still use traditional tracking of odometer difference and tank amounts to determine my ACTUAL mpg (plus I use that to plug into the [garage]) because the SG is not perfect when it comes to tank calculations. It's close but I rely on it for instant feedback on the road.

***
Don't worry about messing it up.