My 2012 is off by 3 MPH, has saved me from being pulled over I'm sure.

 

http://www.toyotanation.com/forum/3...orum/311-avalon-4th-generation-2013-2018/1592962-even-car-doesn-t-know-mph.html

http://www.toyotanation.com/forum/1...07-2011-2nd-gen-solara-2004-2008/1593922-mis-matched-mph-speed-odb2-sensor.html

http://www.toyotanation.com/forum/1...ion-1993-1997/1590866-speedometer-says-i-m-going-faster-than-i-actually-am.html

 

It depends on a lot of factors. IMO

Tires
Size
Pressure etc

 

3-4mph at 75 is typical.

 

you missed the part were i said no matter the speed.
10 mph read 14, 15 mph reads 19, 20 reads 24 mph ,, never owned a vehicle that was off this much.

 

That speedometer.. is just a guide. A mechanical device that displays the results of a whole bunch of variables. It was not designed to be "accurate". The "fix" if it is important.. is to bend the needle.. or change your tire size. This topic has had many posts.. lots of folk are unhappy about it. :smile:
Besides.. the Garmin is not 100% accurate either.

 

Yeah, to know what you're doing. Get caught in a Radar zone and find out the differential. Although it may cost you for that knowledge to determine that. One of my vehicles is different at higher speeds than lower speeds. GPS on my Garmin is different but should be pretty much on the money on a straight level road.

 

One of my vehicles is different at higher speeds than lower speeds.

That's because it's off by a percentage. The faster you go the more it's off.

 

Seems to be "standard" for our cars

From what I have read in other posts all our cars (trucks?) are off by the 3 to 4 MPH. Mine is. All read higher than the speed you are actually going. All have the same error at any speed so it is a fixed number added on rather than a percentage error that changes with speed. It seems Daddy Toyota wanted to avoid being sued for a speedometer that told you a speed lower than your actual speed so he added a fixed error in on purpose. That latter thing is my guess as to why, but it is all I can come up with. Just a personal guess as to why, but they all do it.

 

Federal standards allow for up to 15% error in speed display.
European standards are extremely strict in that the displayed speed MUST be equal to or higher than the actual speed.
Manufacturers tend toward the high side to prevent the speed from reading low under any conditions. 3-5% is miniscule. Japanese motorcycles are typically off by 10% (55=50), though the odometers are only off by about 5%.

If you are within 15% and the indicated speed is above the actual speed, no manufacturer is going to do anything to correct it.

 

I can see in modern America, most especially litigious hell California, some sucking lawyer will sue on behalf of a client rear-ended in an accident, and claim that because the speedometer was in error registering 4 MPH too fast that his/her client, who was driving the speed limit as indicated on the instrument panel, was traveling dangerously slowly and, thus, was rear-ended due to the manufacturer's criminal negligence because the speedometer was set to register too high.

:facepalm:

Of course, the outcome of such a lawsuit--which I'm actually shocked hasn't happened yet--will be that all manufacturers will have to issue recalls and reinstall new speedometers at the cost of billions for the auto manufacturers, while the client and lawyer will bask in an eight-digit monetary compensation.

 

I can see in modern America, most especially litigious hell California, some sucking lawyer will sue on behalf of a client rear-ended in an accident, and claim that because the speedometer was in error registering 4 MPH too fast that his/her client, who was driving the speed limit as indicated on the instrument panel, was traveling dangerously slowly and, thus, was rear-ended due to the manufacturer's criminal negligence because the speedometer was set to register too high.

:facepalm:

Class-action due to the RISK of that happening was actually suggested on a Kawasaki forum I used to hang on ten years ago.
The suggestion was from a particularly OCD Canadian who refused to fix it himself with a Speedo Healer. Even the Californians thought he was nuts.

Apparently, Honda did get spanked over premature warranty expiration due to this, which I still think is nuts. Even if they were 10% off, the difference in resale between 100,000 and 110,000 miles is going to be zilch, and the warranty expiring at 33,000 instead of 36,000... meh

 

I was under the impressionism that while the "speedometer" part was off.. the "odometer" part is pretty accurate... with the correct tires, new..inflated etc.

The problem as I understood it was that the needle, is deliberately placed a few degrees off.. that the manufacturer needs to err on the side of safety given the accumulation of tolerances in the assembling process. If.. you aim for "0" error, some will by high.. some low.. to be safe.. they make them all low

 

Yes, while the speedo is almost always reading too high (1st Gen HL reads accurate, 2nd Gen HL reads high), the odometers are accurate.