I have a ScanGauge, which reads out my xB's ECU stats in real time. It's nice and geeky.

I've noticed the speed is not exactly what is reported on my speedometer (usually lower), and I know there are issues with the speedo being off more and more as you go faster.

However, which is more correct, the speedometer or the ECU? If it says I'm doing 35, am I actually doing 35MPH?

 

on this one street I take home from work the police dept. have one of those speed reading machines and it reads all the time that im going 35mph when the xAs' speedometer states only 20mph I tried different speeds and it still reads higher than what my speedometer reads.so I don't know which is the correct reading...............

 

question is, are those speed radar things correct?

 

Do you or somebody you know have a GPS that will be more accurate than either.

Scott

 

From my experience with several toyotas and several GPS receivers - toyota speedo's (with stock size tires) are usually 2mph above the real speed. So if speedo shows 62, you are actually going 60.

Same 2mph difference was on my matrix, my buddy's corolla, and on the tC.

 

I talked about this with some local motorcycle cops (Sherriffs). They said that it is common practice in the industry to intentionally make speedos read 2 or 3 mph faster than real. The rational is that most drivers tend to drive 10mph over the speed limit. In actuality this would be 7 to 8 mph real speed and a lot of law enforvement people use 10mph over as the point of writting a ticket. Of course this varies according to situation and circumstances. FWIW?

Walt

 

Heh... I usually shoot for 8 or 9 over the speedlimit from my speedometer just to avoid that 10mph barrier. I love cruise control so much...

But I guess now I can maybe tack on that extra 1 or 2 mph...