bigalpha Posted August 9, 2013 Report Share Posted August 9, 2013 I was checking out the engineering test mode (etm) and found that the readout from the ETM was about 3mph lower than what the needle was reading. Anyone else notice this? Quote Link to comment Share on other sites More sharing options...
hybridbear Posted August 9, 2013 Report Share Posted August 9, 2013 This is true in the FFH. When I've driven by radar signs that show your speed they concur with the ET Mode speed. Quote Link to comment Share on other sites More sharing options...
JohnnOhio Posted August 9, 2013 Report Share Posted August 9, 2013 Same here. Radar signs jive with my speedometer Quote Link to comment Share on other sites More sharing options...
bigalpha Posted August 9, 2013 Author Report Share Posted August 9, 2013 Why would the ETM be off that much? Quote Link to comment Share on other sites More sharing options...
hybridbear Posted August 9, 2013 Report Share Posted August 9, 2013 I've found that ET Mode matches radar speed signs. And I've found that a cell phone app using GPS speed seems to be in between the two. Quote Link to comment Share on other sites More sharing options...
bigalpha Posted August 9, 2013 Author Report Share Posted August 9, 2013 Considering the ETM doesn't match the speedometer, I'm immediately suspicious of any other data output by the car. Quote Link to comment Share on other sites More sharing options...
oldloboy Posted August 24, 2013 Report Share Posted August 24, 2013 Considering the ETM doesn't match the speedometer, I'm immediately suspicious of any other data output by the car.Especially your mileage ! Since you have warm temps, which are essential for high mileage results from a hybrid, why is yours reading 36.x mph? Quote Link to comment Share on other sites More sharing options...
plus 3 golfer Posted August 24, 2013 Report Share Posted August 24, 2013 bigalpha, have you checked your odometer for accuracy. I like to use GPS and mileage markers over a larger distance (say at least 30 miles). Most find the odometer reads less than the actual distance covered initially but as tires wear the error will decrease since one revolution of the tire will cover less distance as the tire wears. For example, assume that the multiplier used in computing the odometer reading uses 830 revolutions of the tire to cover one actual mile but the odometer might only show the car actually traveled 0.995 miles (1/2% less distance than actual). As the tire is nearly worn out and the diameter of the tire has decreased, it might take 838 revolutions to cover one actual mile (about 1% more revolutions per mile) and the odometer will show that the car traveled about 1.05 miles (1/2% more distance than actual). The net affect of the odometer error over the tire life will be about zero. But when I checked my odometer over a longer distance initially, mine was showing about a 2% error. I do run about 44 psi in my tires which could account for some of the error as the effective diameter is likely slightly larger than running recommended pressure. So, my FE numbers are likely low by about 2% but will decrease as my tires wear. My speedometer jives with the radar signs and my GPS to less than 1 mph at virtually all speeds. Since I don't normally run with the ETM enabled I've never bothered to check the speed in ETM. However, when I've monitored and recorded speed via the OBDII port, the recorded speed (which I assume would be the same as the ETM speed) and gps speed were very close and the speedometer was about 1/2 - 1 mph too high at 70 mph. Of course each measurement (GPS, speedometer, radar, ETM / OBDII port) has inherent measurement flaws but the 3 mph seems excessive. Quote Link to comment Share on other sites More sharing options...
bigalpha Posted August 24, 2013 Author Report Share Posted August 24, 2013 I checked this again the other day and it looks like the speed between the gauge, the GPS speed from MFT and the ETM speed all jive fairly close. I realize there will always be some variation between the numbers, but before it was a matter of about 3 mph, hence my concern. At this point, though, it looks like that has been resolved. Unfortunately, I didn't take any pics or have any recorded data from any of that. Quote Link to comment Share on other sites More sharing options...
bigalpha Posted August 24, 2013 Author Report Share Posted August 24, 2013 Especially your mileage ! Since you have warm temps, which are essential for high mileage results from a hybrid, why is yours reading 36.x mph? I commute roughly 150 miles a day and almost all of that is 65+ mph. Quote Link to comment Share on other sites More sharing options...
oldloboy Posted August 27, 2013 Report Share Posted August 27, 2013 I commute roughly 150 miles a day and almost all of that is 65+ mph. Oh, yes high speeds would take off some mph. That is a heck of a commute, over an hour each way. Quote Link to comment Share on other sites More sharing options...
bigalpha Posted August 31, 2013 Author Report Share Posted August 31, 2013 Oh, yes high speeds would take off some mph. That is a heck of a commute, over an hour each way. Total commute time for a day is 3 hours. Quote Link to comment Share on other sites More sharing options...
salsaguy Posted September 1, 2013 Report Share Posted September 1, 2013 (edited) big alpha, i hope they are paying you well to compensate for your time spent in traffic/on the road and away from your family. i hope you love your job. anything more than 45-60 min drive for me is too much. Edited September 1, 2013 by salsaguy Quote Link to comment Share on other sites More sharing options...
bigalpha Posted September 1, 2013 Author Report Share Posted September 1, 2013 Luckily, my wife and I work in the same place so we split driving duties. The jobs pay the bills, at least. Quote Link to comment Share on other sites More sharing options...
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