NEW instant MPG calculations

here is it the real way to do it (sortof) I found that there is a value in data block 015 that has a fuel consumption number in liters/hour:

well plug that in with data block 006 and poof instant MPG:

here is the new plot (also included were the calculations we came up with to convert mg/rev to MPG):



the car's computer is putting out slightly higher numbers than the calculations that we came up with but pretty darn close considering everything . . .

what are the numbers at the bottom? i assume it is time, but are they minutes, or seconds?


i need to get me a VAG-COM

[ November 01, 2001: Message edited by: godlike242 ]</p>

seconds,

grabbed me some more cool numbers tonight on the way home,

one cool thing as I was getting ready to leave the parking lot I noticed that at Idle these engines use only 0.4 liters/hour to run!

One full tank of fuel (well 15 gallons) would allow the TDI to idle for 142.5hrs or 5 days and 22.5 hours!!!! lets see an insight or a prius do that

Just to be argumentative...

The Prius or Insight wouldn't need to idle for that long... since the engine shuts off at idle when the battery is charged, I'll bet the hybrids can run for quite a bit longer than the TDI at their supposed "idle".

its more just the 'possiblity' that it could do it -

Park the car out in 0 degree weather and turn the heat to full. The Prius and Insight engines then would have to run to keep the heater going. Then the TDI rules!

I have always thought about this as well. After reading that one of the reasons Turbo Steve never lets the get below half a tank is if they are ever stuck in a snow bank in freezing weather they may need the heat. I figure where I drive they would find me in less than a day, so even 1/8th of a tank should keep me warm that long

[ November 02, 2001: Message edited by: jorpet ]</p>

How long can Vag-com log data for?

I'm driving home to see family this weekend (5hr drive) and i wanted to log the whole trip to see how accurate the numbers are. I think i saw someone mention that it will only go for an hour. Perhaps I can close the log file for a few seconds and open up a new one... wouldn't affect the results, but it's just a pain to have to do that every hour for fear of losing my data.

If you look in the instrument cluster module, there's a reading that gives you fuel level in litres. The only problem is that you need to make sure the car is level when you take the measurement. What I'd like to do is take the reading before i leave, then monitor the consumption for the trip, then take a reading of the fuel level again when i get home. Then i could do it all again on the ride back to finish the tank. I know this probably sounds pretty boring and a bit extreme, but hey, what else am i going to do in the car for 5 hours? I mean besides drive (for any of you potential wiseguys out there )

I tried comparing the figures for litres/hour and mg/rev before and think i came to similar results... about 7 or 8% difference between the two.

[ November 02, 2001: Message edited by: Vroom ]</p>

vroom,

I think there is an issue with the ISO bus - it must get choked with data coming from teh ECU either that or the ECU is deciding to be grumpy and stop sharing it's precious data.

I've gotten it to record for at most I think 45 minutes. Once it stops talking (doesn't have to do with the data logging) the only way to get it to communicate with the engine (you can get data from every other module) is to turn the key off and re-start the program, Vag-com or VWTool.

somewhat of a problem that I would like to know how to overcome. Is it com port speed? settings to fast? if you force is slower does it last longer?

anyone have thoughts on that?