Speedo over reading and the effects.

[Eddie17 546]

Really interesting reading this topic ,learning a lot . I often wonder why in this day and age our vehicles are not governed to speed traffic limits with all this technology . Must be something financial in that ..... On a silly note the only accurate level measured mile I know of is off Isle of  Arran definitely not suitable 🤔

Edited September 7, 2019 by Eddie17

[Defender 3,838]

17 hours ago, alhendo1 said:

This has got me interested☺..if this has been covered prior to my time on the forum please accept my apologies.......having read DaveM59s post yesterday re the new scooter and the Forza speedo over reading 77mph versus 70 mph I had a look online and it appears from what I can see cars and motorcycles sold in the UK generally overestimate your speed (not legally allowed to underestimate ) ...now I've not ran a Gps app to see if my 2018 CB500x is overestimating but it definately feels as if it does.Quite a number of times I've driven through villages/towns where you get the smiley/sad face sensor thingy clocking your speed and the results suggest the speedo is ambitious....eg yesterday two of them said I was doing 29mph when my speedo said 32mph....so I have a couple of questions. 

 Let's say the speedo is 10% overestimating....does the speedometer work from the same sensor as the odometer? If so does that mean my bikes stated mileage will be showing 10% more than it's actually done.....and if that's the case then when I'm calculating my mpg figures (manually...litres to gallons then divide miles covered by gallons) then the result won't be so generous. I have had a look online and there are some discussions but they tend to fizzle out with no real answer. Please feel free to tell me if I'm overthinking this one...😅....your input would be appreciated. 

 

 

With regard to the over reading etc, you vehicle knows exactly and precisely how fast it is going, I have had a ScanGauge II on my last four cars, all four cars over read on the speedometer but the speed reading on the Scangauge was spot when measured against several GPS devices measuring speed.

So you're odometer reading should be spot on. There has to be a small allowance for the differences in diameter between new and a worn tyres and slight differences in overall diameter between different tyre manufactures tyres.

 

[SteveThackery 3,090]

Talking of chronometrics, a mate of mine makes an excellent living from restoring them.  He has found suppliers for every single component and can, in fact, make a brand new one if required.  He has customers all over the world.

[Andy m 23,764]

9 hours ago, Eddie17 said:

. I often wonder why in this day and age our vehicles are not governed to speed traffic limits with all this technology . Must be something financial in that .....

 

There is no technological reason. Telematics and the speed limiter/cruise control technology already in most vehicles make it not only cost free to most manufacturers but something the vehicle makers would sell (tracker, connectivity offers, traffic services etc.). The over rides to "accelerate out of trouble" already exist. 

 

We don't have it for the simple reason it the market dislikes it. How do you sell a 100HP Ducati with the performance of a 250. Ride to Live, live to ride, just do it in the way the computer allows lack a certain flow. 

 

Our current overlords in Brussels are about to enact legislation to level the playing field. When every new vehicle has to have this it will become the norm. We will welcome it in camera infested areas and new drivers will come to rely on it. 

 

The big brother aspect is not the speed (they will lower the speeds on the principle that drilling a hole in your head didn't cure your cold, so better drill another), you will be able to over ride this. When the sewer ants start to charge more for the Helmsley TT route and the limiter allows an extra 5 mph so long as you are routed via Maccy D's we are in trouble. 

 

Andy

Edited September 7, 2019 by Andy m