External MPG display

When I went to visit Mike Dabrowski a month or so ago (he's the guy with the very tricked-out Insight, and who has plans to use a modified Prius transaxle to create an Insight EV) I found out that he had done this but had to take it down. Apparently some law enforcement officer somewhere took exception to it on the grounds that it was distracting or something. All I'm saying is check local laws first.

 

<div class='quotetop'>QUOTE(Bruski @ Apr 29 2007, 09:03 AM) [snapback]432071[/snapback]</div>

The easiest way would be to buy an OBD2 unit that can display the MPG (this puts a lower cost unit at risk). Then tap into it to drive a large rear display. You could ask the engineers at "ScanGuage" or the developer of the "CANview" about an external display feature.

JeffD

 

<div class='quotetop'>QUOTE(Bruski @ Apr 29 2007, 09:03 AM) [snapback]432071[/snapback]</div>

You don't have to hack the computer. The information is available from the CAN bus.

Tom

 

<div class='quotetop'>QUOTE(qbee42 @ Apr 29 2007, 09:52 PM) [snapback]432321[/snapback]</div>

If this thing does get produced, instead of 99.9 MPG, it should read >100 MPG or "Infinity" just so someone following you doesn't think that you are actually getting exactly 99.9.

We Prius owners know what 99.9 really means, but I don't think we can count on everyone else knowing that.

 

<div class='quotetop'>QUOTE(avdavsim @ Apr 30 2007, 11:27 AM) [snapback]432657[/snapback]</div>

I am looking forward to when Toyota feels the need to add another diget to the display. Hopefully a full digit, not a half digit that can only display a 1. This will obviously be needed for the 100+ MPG Prius which will be had by all current owners with a free battery pack upgrade and firmware update.

 

When my Prius Display shows 99.9mpg, my scangauge2 shows 9999.99mpg when the engine is off. But other times when the engine is still running only at idle the SG2 might show numbers like 120mpg. The SG2 provides me with higher limits than the Prius display.

 

Taking the OP's suggestion a step further: How 'bout the external display being user-programmable with text capabilities: "Get off my a**."

 

<div class='quotetop'>QUOTE(qbee42 @ Apr 30 2007, 11:52 AM) [snapback]432321[/snapback]</div>

The CAN message does not have a direct MPG number.
You have to do complex math to get the MPG number.

<div class='quotetop'>QUOTE(Rest @ May 2 2007, 03:13 PM) [snapback]433784[/snapback]</div>

The ScanGause tells us a truth, 9999.99 mpg when the engine is off at below 42 mph.
But, it tells us a lie, 120 mpg when the engine is fuel-cut mode at above 42 mph.

Ken@Japan

 

This remainds me of the NASA pen USSR pencil thing.

Why not write your MPG on a bit of paper and Bluetac it on to the window. A good time to do this is just before you fill up.

 

http://www.streettags.com/Vehicle_window_L...p/ns-100-er.htm

(not a product endorsement)

 

<div class='quotetop'>QUOTE(tochatihu @ May 3 2007, 09:29 AM) [snapback]434663[/snapback]</div>

Not sure how practical that is for the Prius; not sure where it would mount. But this product on the same site looks like it has possbilities.

 

And if you want a little larger display, here is one I found on that same site (again, not an endorsement): Mobileled MD-550

Sometimes you can still find these on ebay for under $100.

If you google "mobileled md-550" you'll find links to old/dead web pages. So I turned to the Internet Archive Wayback Machine for help.
Using the wayback machine I found this link with some general info and this link to the brochure

Have fun!

 

I did something similar when I had an Insight:

It was very basic, I found some very large 7-segment displays, I connected both displays to ground and I attached a 12V lead to each segment I wanted illuminated to create numbers. It was very primitive in terms of electronics, but it worked (until segments began to burn out because I didn't use any resistors... d'oh!).