Modern Vespa

Found it curious that the total miles displayed on the Vespa app doesn't match the total miles travelled by my Vespa odometer.

Turned on the Vespa and reconnected a second time, and still showing 2 miles different…

I want my 2 miles...

I don't really know where your 2 miles are, but I was going to suggest you lighten up the key ring that has the Vespa key on it. This is known to cause havoc with the ignition switch after a while.

Not only that, but the hole in the Vespa key isn't that strong - you could lose all the other keys just going over a harsh bump.

ok, I dug into this for you. App bug unsurprisingly.

the app is receiving the odo value from the bike as miles*, ie 5998. It converts this to kms using 1.61 which is 9656.78km and then stores it. At display time it converts it to miles using 0.621371 giving 6000 miles.

PS, even worse for some bikes it uses 1.60934 in the first step which correctly becomes 5998 when displayed.

* this is poor design of the tft module + pmp protocol that if well designed would always send an accurate value in a consistent unit and kms are more accurate then miles. Hmm, looked further and on some models it is always kms and on some it sends based on the dash display mode.

That's the distance between your phone and the scooters brain multiplied by every ride.

More importantly, that is some seriously impressive MPG figures.

This ^^^

SERIOUSLY impressive

Bear in mind that those MPG figures are with the UK gallon. So, about 119 MPG here with the US gallon, but still not bad at all.

Well for the mpg on a Primavera in the app:

pre - Euro 5: the injection timing and rpm are retrieved from the ecu and mashed together to create litres/hour.

Euro 5: the throttle and rpm are mashed together (using different consts for a 125 vs 150) to create the litres/hour.

The litres/hour is then mashed with the speedo to create kms/litre which is displayed in the users preferred units.

Of course such estimation ain't gonna be perfect ...

Bonus comment: the app does check if the phone's regional settings are US or not and uses US or UK gallons. No idea what the dashboard does for this distinction - does it offer the user the choice, too lazy to dig through the manuals?

PS for a GTS the ecu supplies the litres/hour directly. (injection timing is also avail but not used in these calcs)

One would have thought counting injection pulses would be the most accurate. Or at least the most consistent.

Firkins per furlongs next...

The ECU can do a more accurate calculation of litres/hour. This is because it of course has the timing of every single injection. The piaggio app only gets a sample of things every 250ms.

So why doesn't the prima get litres/hour from the ecu? Because I'm pretty sure that ecu (EFI Tech) doesn't make this available on the canbus unlike the gts ecu (Magnetti) which does.


* Bonus note my app uses 100ms on PMP2, haven't tested to see how fast I can push PMP3.

Which is pretty much counting injection pulses. That is.. ...slow. Push it.

I have the rate configurable but don't have a PMP3 scoot to test on. Waiting for a user to do some testing and let me know what is stable then I can set a default.

Note: PMP3 uses Bluetooth LE which is slower than PMP2 which uses Bluetooth 'classic'. ie piaggio took a backwards step when switching to a new supplier: pmp3 is made by Hella (india) and pmp2 is by DQuid (italy)

Love it! Thanks, I wasn't aware of this! I've decided to separate off my blue key now, and will either run it on its own or with a small single keyring to make it more visible. Thanks! Very interesting to hear how they've calculated all of this! 90% of the time, I always use full throttle launches. I found my clutch would get glazed with slower launches and would take a few weeks to clean back up again.

I think the key to the mpg has been that my favourite roads are 30-40mph roads as I'm a "big fish in a small pond". I can filter at traffic lights, and I've got pace to overtake.

I still do use some 60mph roads on a daily basis though. I top out at 60mph, but I've noticed that modulating the throttle and sitting at 50-55mph is much better for mpg than going full throttle for 20 minutes or so at a time.

My favourite two mpg figures were going over the alps into Italy. Big difference between climbing and dropping back down!

Good point! There's no metal in the loop it's just plastic.

that happened to the key for my old gts which has that soft-ish feeling plastic.

the key with my hpe is a harder plastic and is lasting just fine.

here's some solutions (not sure how the aluminium ones go with the immobiliser)

https://www.aliexpress.com/item/1005003945281414.html
https://www.aliexpress.com/item/1005001596186044.html
https://www.aliexpress.com/item/1005006858478681.html
https://www.aliexpress.com/item/1005006130992052.html

Super cool thank you!