I ordered a ScanGauge last week. Received it yesterday. I installed it in the EX Civic for the drive home. I know the car had 50 mpg ave. in it. Its in the Accord for the rest of the week.

More on the SG here
http://www.cleanmpg.com/forums/showt...=1791#post1791

A very ugly welcome addition to my motoring needs.

 

I am so, SO jealous of new cars. Seriously, ever since I got a short commute (only 8 miles each way, 4 of which is wide-open freeway) I've not had a single tank reach 40mpg in my Civic. They've all been 37-39 or so. I swear, I should put the blame on my car having 146,000 miles now. I mean, it can't possibly be anything I'm doing wrong, right? Well maybe I could take surface streets instead of the freeway, but that would add many minutes and more red lights. Ah well, I guess I should be happy with the fact that 8 miles at 38mpg is still a lot less gas used than 21 miles at 42mpg.

By the way, I'm glad you're enjoying your ScanGauge. I got to try mine out in a friend's Jeep Wrangler 4.0 last week. Boy, nothing will make your eyes pop out of your head like seeing the instant MPG go from 2, to 4, to 6mpg as you accellerate in 1st, 2nd, and 3rd gears. That and the fact you'll just plain never see it over 30mpg, and anything much over 20mpg requires you to be under 55mph. Really, the stunner for me was seeing it showing 0.6 gallons per hour at idle, fully warmed. My HX draws 0.1gph fully warmed, and 0.2 - 0.3 even with the A/C on. Yikes, no wonder my Wrangler friend has difficulty getting over 16-18mpg on a day to day basis.

 

A handy use for a ScanGauge is to find suitable sites (I used four) and measure the fuel economy of your car on level roads. Run both ways to minimize the effects of grade and wind, and pick a day with moderate temperatures and low wind. Use the cruise control to keep speed steady. I did this on my 2006 Honda Accord 4 cyl Stick (40 psi tires) and the results were surprising to me. MPG is 58.9 at 26 mph in 5th gear. It drops to 37.6 at 70 mph. In between the MPG follows an almost straight line. In 4th gear, the results are about 8 mpg less at any speed. Clearly the high fuel mileage goes to the person driving slowly in top gear. I don't know how things go on an automatic transmission, but I can get 35 mpg on a trip to the grocery 3 miles away. My wife can get over 40 MPG on a 12 mile trip on local and 50 mph roads. Happy to email the graph (from Excel) to anyone.

 

Don, I did the same sort of testing actually. In my Civic HX, I ended up having to show a sort of dotted line of what I felt were the "right" numbers since the ScanGauge doesn't recognise the HX's lean-burn mode, which seemed to skew the numbers through the midrange. I plotted the reported values for the Prius above it. Like you said, it's pretty much a straight line.

 

But I went to 26 mph, the lowest speed my cruise will run at. Let's see if I can post a graph here.

No, I would but I don't know how. Tell me how and il willl post the graph.

Anyway, the graph shows you have to learn how to drive again to get good econmy.

 

Where did you get the Prius numbers?

The reason I ask is my NHW11 gets something quitie different. The only source for a straight line I've seen are the various Prius simulators and I'm not convenced they are accurate in the 39-50 MPH range.

Bob Wilson

 

Here is the MPG chart I mentioned. It is as good as you can do with no wind on level roads in cruise control. Based on tests I ran, a few times in each direction to minimize grade and wind effects.. Four different roads were used, for safety's sake. It is best to do this at the posted speed limit if you can. 40 psi tire inflation was the only non-stock item.

 

It was from a graph someone gave me based on the data from http://os2.mystarband.net/ <- that site for roughly 70 degree day, standard tire pressures. You could be right that it's not accurate in that transitional range between electric and gas-only cruising. Who knows!

Hey Ole_Don, I noticed you can use 5th gear at 25mph. What RPM does your engine turn at that speed according to the scangauge? My HX has very tall gearing and spins around 1310rpm in 5th at 35 mph, making that the lowest speed I can use 5th without lugging.

 

Hi, Brandon. I ran out to find out the rpm at 25 mph. In the first place, 26 mph is a better lower end of the cruise control speed range, and the chart point is at 26 mph.

I found that finding the rpm at 25 mph is not easy because of speed changes and the ScanGauge needing a time to make a number. So, I got on a 50 mph road with cruise control and found that 1943 rpm at 50 mph is pretty consistent. That would give 971 at 25 mph. That value did come up (as well as other ones) at 25 mph.

Because of the 40 psi tires, and the low rolling resistance, I can idle in 5th at roughly 18 mph in 5th gear on level streets.

 

Wow! The Accord's engine must be much better tuned. My Civic will buck and even misfire if I try to lug anything below about 1150 - 1200rpm in 5th gear. It can pull lower gears better, but once you're in 5th, it just has major problems even running right at such low speed. I'm jealous of your super low RPM ability!