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Speedo is off by 3mph
Posted: Tue Sep 28, 2010 8:59 pm
by sloopercat
Long interstate drive today. I normally drive 8+. I was getting passed regularly, normally folks are not pushing it that hard. I grab the GPS, at 78 indicated on the speedo it says 75 on the GPS. For fun I reset the average speed display, it agrees with the GPS. Any body else notice this? Percentage wise not a big error, but thought it was interesting the speedo and average speed indicator do not agree.
Re: Speedo is off by 3mph
Posted: Tue Sep 28, 2010 9:32 pm
by gaww
Mine is off by 2 mph at 70. This has been noted by others also.
Re: Speedo is off by 3mph
Posted: Tue Sep 28, 2010 10:03 pm
by sloopercat
Just seems odd the digital readout is spot on, but the needle is that far off. Good to know, saves me half an hour each way on the trip to see my parents over Thanksgiving.
Re: Speedo is off by 3mph
Posted: Wed Sep 29, 2010 3:42 am
by TheHolyGhost
I have yet to own a car where the speedometer wasn't a tad on the high side. I think automakers do it on purpose actually.
Re: Speedo is off by 3mph
Posted: Wed Sep 29, 2010 5:08 am
by Minority
Mine is reading at least 5% fast (when compared to my GPS), As Ghost says I think every car I have owned has been the same ( to a greater or lesser extent) and may be done to stop the manufacturers getting sued when you get your speeding ticket

Re: Speedo is off by 3mph
Posted: Wed Sep 29, 2010 1:22 pm
by sloopercat
My experience is that they are usually spot on. Explains that 20 percentile pack of folks that all drive 7-8+ to avoid a ticket. I drive a lot and do that 8+ all the time and generally stay in the pack, in at least 2 rental cars per month and they never run consistently low. +5% will not get you a ticket in most jurisdictions.
Re: Speedo is off by 3mph
Posted: Thu Sep 30, 2010 4:42 am
by TheHolyGhost
Interesting note that I read when I was researching whether manufacturers intentionally set them to read high. The site mentioned that this probably also means that your odometer is advancing more quickly than it should. That is something that I would want fixed!
Re: Speedo is off by 3mph
Posted: Thu Sep 30, 2010 6:01 pm
by sloopercat
TheHolyGhost wrote:Interesting note that I read when I was researching whether manufacturers intentionally set them to read high. The site mentioned that this probably also means that your odometer is advancing more quickly than it should. That is something that I would want fixed!
Honda had a legal settlement over having the ODO read fast and reducing warranty coverages.
Re: Speedo is off by 3mph
Posted: Fri Oct 01, 2010 3:28 am
by GREG
mine also reads +3 on the speedo BUT, on a trip with my gps I noticed that the actual miles on the trip meter and the gps trip were within 2 miles over 300 miles. This would mean that the speedo and odo are independent of each other.
Re: Speedo is off by 3mph
Posted: Fri Oct 01, 2010 12:51 pm
by babacu
There's something off there, for sure. I use trip A for keeping track of distance between fill-ups and trip B for oil changes. Until the first oil change trip B was not staying in sync with the main odometer's reading, although they should have been the same. Speed aside, the two counters were not aligned, and they're both electronic.
I don't notice it anymore now that I reset trip B and it's not as obvious (and I don't really keep track), but I guess one can still check this if so desired.