07 touring speedo

:huh: Funny you should mention! I got my ScanGauge II yesterday and used it a lot today and one of my observations were the differences in the mph of the Speedo and the S/G. I wondered if there was a calibration done for the larger wheels myself, although both the guages should be getting the same data..... I will use my Garmin Nuvi tomorrow to compare speeds with the GPS.

Anyone have definitive answer?

 

<_< From time to time, radar-equipped 'speed trailers' are parked on the Dallas TX city streets - to remind you of your actual speed. These 'trailers' read EXACTLY the same as my onboard speedometer - no variance, exactly the same.

I'm sure you know, but the MPH readings depend on the revs/mile of the wheel, so the 16" wheel is not the issue, rather the combination of the 16" wheel and the Bridgestone Turanza tires, the exact circumference of the complete assembly.

 

I would hope that Toyota engineers would take the Touring Edition wheels into consideration. Since I have a regular edition (standard edition, non-touring edition, plain Jane edition?) I can't say for sure. One thing I would try is recalibration, just like you would do with new tires.

Before you go for a drive, press the bezel Menu button, then the Setup screen button. Page down to the third screen and press the Calibration Adjust button. This tells the Nav system something has changed. It will try to reconcile wheel-rotation-impulses with GPS changes to get the wheels and nav coördinated.

Then find Charles's radar signs or a freeway with measured miles and see if they now correspond. I guess you can also use your external GPS unit to check. Let us know if you still have calibration issues.

 

<div class='quotetop'>QUOTE(bradysplace @ Mar 17 2007, 03:42 PM) [snapback]407299[/snapback]</div>

My bet is Toyota follows UN-ECE Regulation No.39.
http://www.unece.org/trans/main/wp29/wp29regs/39rv1e.pdf

Ken@Japan

 

Ken, does Regulation 39 specifically mandate reporting an incorrect speed?

 

<div class='quotetop'>QUOTE(Bill Merchant @ Mar 18 2007, 04:35 PM) [snapback]407780[/snapback]</div>

If you read the PDF regulation carefylly to the last page , you'll find the speedometer reading should be...
0 =< (display - actual ) =< 10% of actual + 6 km/h
So, the display value should never been shown below actual and is allowed 10% of actual + 6 km/h more, then the display is intentionally biased about 5 km/h (3 mph) higher than actual.
Toyota and other car manufacturers are just following the regulation.

Ken@Japan

 

<div class='quotetop'>QUOTE(ken1784 @ Mar 18 2007, 03:15 AM) [snapback]407792[/snapback]</div>

Ken & Bill, the way I read this is that the speedometer is within the regulation as long as the difference is less than 10% + 6km/h (3.6miles). So in the US at 60mph the speedometer can read from 60 up to 69mph and still be in compliance. If it reads 70mph then it is not in compliance. In the first instance it sounds like Toyota can claim the unit is within spec and does not have to replace it. In the second instance it sounds like the speedometer could be replaced for a more accurate one under warranty.

 

My speedometer totally agrees with what my GPS unit tells me my speed is.

 

I've had my '07 Touring for 10 days now. Finally took it on a 3 hour highway trip last evening and wanted to verify the speedometer.

I used a stopwatch and checked the time for 5 one mile segments at 79mph on cruise. Each segment took on average 45.6 seconds. So the speedo is accurate enough for me!!!

 

Do the mphhave anything to do with the mpg calculation? Reason I'm asking is..I have a 2006 Prius. Today I went to the dealer because I love my Prius so much, I want another. I test drove a package 3 touring edition. And like the initial poster was commenting, there was just something off for me. Just like he said, you get to know the feel of the car once you've driven it enough. And, what was off for me was the mpg. I couldn't get that thing to respond to my Prius driving like my 2006. By the time I left the dealer I had 19 miles on the car and the energy consumption score..or whatever..anyway, it only read about 22.3 mpg. I also test drove a standard 2007 and it did respond to my driving like I am used to. I love the options and the price they were offering but walked away to think about it because I was so concerned about the performance (mpg). Any thoughts?

 

The mpg display is based on distance traveled and fuel used.
The speedometer reading is intentionally biased, but odometer reading is very accurate using standard size tires.

Any car needs certain amount of warming up fuel, so any car shows low mpg number on short trips.
Your 23.3 mpg for 19 miles is not a good reference.

Ken@Japan

 

I have an 07 touring pkg 6 and get 48 mpg consistently with 1600 miles driven. I would think you would have to drive the car for several tanks to compare MPG between the 2 trim levels

 

The speedometer doesn't overread on US Priuses. But it does, deliberately, on European and Japanese ones.

 

<div class='quotetop'>QUOTE(KMO @ Mar 27 2007, 09:57 AM) [snapback]412620[/snapback]</div>

Are you sure it is true on 07 Prius too?
Camry Hybrid owners reported offset speedometer readings.

Ken@Japan

 

<div class='quotetop'>QUOTE(KMO @ Mar 26 2007, 06:57 PM) [snapback]412620[/snapback]</div>

I can confirm that my european '07 Executive (~#6-8) has got ~8% bias on the speedo compared to GPS AND MFD Servicemode

/e

 

<div class='quotetop'>QUOTE(Erik Sweden @ Jun 7 2007, 05:40 PM) [snapback]457648[/snapback]</div>

Whoops, that is only ~5%, but actually it was jumping between 64 and 65 Mph and simultaneously between 102 and 104 Km/h so it is probably a mph value internally and translated to Km/h.
I tested at different speeds: VehicleSignal=25, Speedo=29; Vs=50, S=55 and as you see VS=104(103?), S=110

/e

 

<div class='quotetop'>QUOTE(Erik Sweden @ Jun 8 2007, 07:51 AM) [snapback]457654[/snapback]</div>

Our observation is not fixed percentage, but the offset is always plus 6 km/h from actual speed.
Japanese later model has only 3 km/h offset.

Ken@Japan

 

<div class='quotetop'>QUOTE(KMO @ Mar 26 2007, 04:57 PM) [snapback]412620[/snapback]</div>

My apologies in advance if this is a dumb question - but why would the speedometer be deliberately programmed to over read?