Scan Gauge and PHEV

Hi All,

I use my scan gauge everyday and it it extrememly useful for watching the prius battery voltage and current flow, etc.

However, I recently noticed the following interesting inconsistency. I drive to work (mostly downhill) with the Enginer running and I get 140 to 150 mpg on my 23 mile trip to work. Then for the 23 miles on the way back (mostly uphill) I get 50 to 60 mpg based on the CURRENT indication on the scan gauge. If I were to average these two numbers it would be 100 mpg. However, TODAY indicates more like 85 mpg for the whole round trip. Yes, I have the scan gauge in the hybrid mode. 85 mpg is close to what the MFD indicates. I don't believe I'm really getting 100 mpg, I'm really getting 85 mpg, but this inconsistency bugs me. So, has anyone noticed this type of inconsistency? What causes this? How could I correct this? Is there something wrong with my scan gauge?

Since the MFD seems to read high I'd like to believe the scan gauge and I calibrated it very carefully (or so I thought) before I installed the Enginer and with an 8.5% correction factor it read very close to what I got by calucating the old fashioned way for gallons put back into the tank. Maybe the scan gauge doesn't handle EV mode very accurately??? Or it has something to do with the correction factor??? Is this just the best you can do, since my driving conditions change so much during one day? Any thoughts?

I pretty much see this effect every day. This is not a big problem, but I'm curious if others have seen this.

Thanks,

Art

 

Hi fuzzy1,

Wow, I thought I knew some math, but maybe not. OK, I was doing the math averaging wrong by just blindly averaging 50 mpg and 150 mpg to get 100 mpg. Seems like a silly mistake after seeing your post, but I appreciate you spelling it out for me.

Thanks,

Art