My 2016 Prius Two had been consistently getting 52mpg since I bought it new two years ago. I switched insurance carriers to All State and agree to have a telematics device installed to measure my driving habits and thus qualify me for a rate reduction. From the time I inserted the device in the port under the steering wheel it seems my mileage has dropped 3-4 mpg. Nothing else has changed in my driving. I am tempted to remove it for several days to see if my mileage returns to what I consider normal. Has anyone else experienced a mileage drop after installing a similar sensor for an insurance company? Thank you.. Casey
I wouldn't expect the device to have any impact, but it's hard to rule it out too. Some people subtly change their driving patterns when they know the insurance company is watching- possibly enough to bump the MPG? Tough to say. Most insurance companies only need to pull a 30-day sample. I guess I would run out the clock and see if it gets better afterward.
There's no way the telematics device will affect your fuel economy, other than the almost immeasurably small reduction in economy due to the mass it adds to your car, and the additional tiny electrical power drain. They only read the very basic standard ODBII protocol data (e.g. speed). They can't make any adjustments. I would suggest it's things like the warmer weather increasing the load on your aircon.
how do we know the device can't be used by unscrupulous people with black boxes that can intercept and reprogram prius ecu's?
It's theoretically possible to create an ODB dongle that can reprogram a specific make and model of vehicle, either by adjusting factory settings, or updating the firmware (which puts the car out of action for several minutes so would be kind of noticeable). Given the huge number of variants of protocols, ECUs, makes, models, etc of vehicles, it simple wouldn't be economically possible to do this (nobody will pay thousands per dongle, nor hundreds of thousands for development, to achieve this). But let's assume a Prius is targeted, and they have some way to adjust some setting that drops someone's MPG by an almost unnoticeable amount, that is so small it's insignificant compared to the the day's weather conditions or tiny variations in a person's driving style... Why? Why would anyone want to do this? What would it achieve? And how would it be worth the expense in research, development, and production, to create these devices to ship to insurance customers, and how would it justify the risk of (quite easily) getting caught? Pixel 2 ?
What about a data gathering dongle that polls too frequently and inadvertently creates a denial-of-service situation where the ECU can't maintain normal operations? That situation doesn't require any specific targeting or even bad intent. ...what about a perfectly ordinary dongle with a loose connection, flooding the channel with NACKs or the equivalent? I really, really don't think that's what's going on here, just swimming the seas of speculation...
You can DOS OBD, sure, and it can have weird effects. In my previous vehicle, the steering warning light would come on, but nothing else happened. I can't say much more as my experience is limited in this area of pentesting. Pixel 2 ?
Odd - if anything, I'd have expected it to have improved with you aware that "big brother" is monitoring your driving. I GOOGLED "Telematics device hurting mileage" - and it came up with not just this thread, but some interesting complaints, though none about PRIUS - maybe worth reading.
Ive had the Bluetooth dongle connected to torque occasionally toss a check engine light when your watching active data.. in the screen. I think the excessive polling of the data can cause some issue. I'm driving a 2008 with 236,000 miles. SM-N950U using PriusChat mobile app
I have an Automatic Pro connected to my 2018 Prius Two and don't have any issues with mileage, in fact on my commute home today I was able to drive over 30 miles and obtain over 70mpg according to both the car and the device.
